summaryrefslogtreecommitdiffstats
path: root/feature-pooling-dmaap/src/main
diff options
context:
space:
mode:
Diffstat (limited to 'feature-pooling-dmaap/src/main')
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/DmaapManager.java294
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/EventQueue.java121
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/FeatureEnabledChecker.java144
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeature.java390
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureException.java59
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureRtException.java50
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManager.java152
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManagerImpl.java871
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingProperties.java162
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/Serializer.java79
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/SpecProperties.java109
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java466
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/Extractor.java35
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ExtractorException.java49
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java59
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MapExtractor.java60
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MethodExtractor.java58
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/BucketAssignments.java215
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Forward.java180
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Heartbeat.java60
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Identification.java45
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Leader.java75
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Message.java103
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/MessageWithAssignments.java77
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Offline.java45
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Query.java44
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ActiveState.java255
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/FilterUtils.java96
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/IdleState.java85
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/InactiveState.java55
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ProcessingState.java410
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/QueryState.java209
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StartState.java132
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/State.java370
-rw-r--r--feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StateTimerTask.java37
-rw-r--r--feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.core.PolicySessionFeatureAPI1
-rw-r--r--feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.DroolsControllerFeatureAPI1
-rw-r--r--feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.PolicyControllerFeatureAPI1
38 files changed, 5654 insertions, 0 deletions
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/DmaapManager.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/DmaapManager.java
new file mode 100644
index 00000000..98543f29
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/DmaapManager.java
@@ -0,0 +1,294 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.util.List;
+import java.util.Properties;
+import org.onap.policy.drools.event.comm.FilterableTopicSource;
+import org.onap.policy.drools.event.comm.TopicEndpoint;
+import org.onap.policy.drools.event.comm.TopicListener;
+import org.onap.policy.drools.event.comm.TopicSink;
+import org.onap.policy.drools.event.comm.TopicSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Manages the internal DMaaP topic.
+ */
+public class DmaapManager {
+
+ private static final Logger logger = LoggerFactory.getLogger(DmaapManager.class);
+
+ /**
+ * Factory used to construct objects.
+ */
+ private static Factory factory = new Factory();
+
+ /**
+ * Name of the DMaaP topic.
+ */
+ private final String topic;
+
+ /**
+ * Topic source whose filter is to be manipulated.
+ */
+ private final FilterableTopicSource topicSource;
+
+ /**
+ * Where to publish messages.
+ */
+ private final TopicSink topicSink;
+
+ /**
+ * Topic sources. In theory, there's only one item in this list, the
+ * internal DMaaP topic.
+ */
+ private final List<TopicSource> sources;
+
+ /**
+ * Topic sinks. In theory, there's only one item in this list, the internal
+ * DMaaP topic.
+ */
+ private final List<TopicSink> sinks;
+
+ /**
+ * {@code True} if the consumer is running, {@code false} otherwise.
+ */
+ private boolean consuming = false;
+
+ /**
+ * {@code True} if the publisher is running, {@code false} otherwise.
+ */
+ private boolean publishing = false;
+
+ /**
+ * Constructs the manager, but does not start the source or sink.
+ *
+ * @param topic name of the internal DMaaP topic
+ * @param props properties to configure the topic source & sink
+ * @throws PoolingFeatureException if an error occurs
+ */
+ public DmaapManager(String topic, Properties props) throws PoolingFeatureException {
+
+ logger.info("initializing bus for topic {}", topic);
+
+ try {
+ this.topic = topic;
+ this.sources = factory.initTopicSources(props);
+ this.sinks = factory.initTopicSinks(props);
+
+ this.topicSource = findTopicSource();
+ this.topicSink = findTopicSink();
+
+ // verify that we can set the filter
+ setFilter(null);
+
+ } catch (IllegalArgumentException e) {
+ logger.error("failed to attach to topic {}", topic);
+ throw new PoolingFeatureException(e);
+ }
+ }
+
+ protected static Factory getFactory() {
+ return factory;
+ }
+
+ /**
+ * Used by junit tests to set the factory used to create various objects
+ * used by this class.
+ *
+ * @param factory the new factory
+ */
+ protected static void setFactory(Factory factory) {
+ DmaapManager.factory = factory;
+ }
+
+ public String getTopic() {
+ return topic;
+ }
+
+ /**
+ * Finds the topic source associated with the internal DMaaP topic.
+ *
+ * @return the topic source
+ * @throws PoolingFeatureException if the source doesn't exist or is not
+ * filterable
+ */
+ private FilterableTopicSource findTopicSource() throws PoolingFeatureException {
+ for (TopicSource src : sources) {
+ if (topic.equals(src.getTopic())) {
+ if (src instanceof FilterableTopicSource) {
+ return (FilterableTopicSource) src;
+
+ } else {
+ throw new PoolingFeatureException("topic source " + topic + " is not filterable");
+ }
+ }
+ }
+
+ throw new PoolingFeatureException("missing topic source " + topic);
+ }
+
+ /**
+ * Finds the topic sink associated with the internal DMaaP topic.
+ *
+ * @return the topic sink
+ * @throws PoolingFeatureException if the sink doesn't exist
+ */
+ private TopicSink findTopicSink() throws PoolingFeatureException {
+ for (TopicSink sink : sinks) {
+ if (topic.equals(sink.getTopic())) {
+ return sink;
+ }
+ }
+
+ throw new PoolingFeatureException("missing topic sink " + topic);
+ }
+
+ /**
+ * Starts the publisher, if it isn't already running.
+ *
+ * @throws PoolingFeatureException if an error occurs
+ */
+ public void startPublisher() throws PoolingFeatureException {
+ if (publishing) {
+ return;
+ }
+
+ try {
+ topicSink.start();
+ publishing = true;
+
+ } catch (IllegalStateException e) {
+ throw new PoolingFeatureException("cannot start topic sink " + topic, e);
+ }
+ }
+
+ /**
+ * Stops the publisher.
+ */
+ public void stopPublisher() {
+ if (!publishing) {
+ return;
+ }
+
+ try {
+ publishing = false;
+ topicSink.stop();
+
+ } catch (IllegalStateException e) {
+ logger.error("cannot stop sink for topic {}", topic, e);
+ }
+ }
+
+ /**
+ * Starts the consumer, if it isn't already running.
+ *
+ * @param listener listener to register with the source
+ */
+ public void startConsumer(TopicListener listener) {
+ if (consuming) {
+ return;
+ }
+
+ topicSource.register(listener);
+ consuming = true;
+ }
+
+ /**
+ * Stops the consumer.
+ *
+ * @param listener listener to unregister with the source
+ */
+ public void stopConsumer(TopicListener listener) {
+ if (!consuming) {
+ return;
+ }
+
+ consuming = false;
+ topicSource.unregister(listener);
+ }
+
+ /**
+ * Sets the server-side filter to be used by the consumer.
+ *
+ * @param filter the filter string, or {@code null} if no filter is to be
+ * used
+ * @throws PoolingFeatureException if the topic is not filterable
+ */
+ public void setFilter(String filter) throws PoolingFeatureException {
+ try {
+ topicSource.setFilter(filter);
+
+ } catch (UnsupportedOperationException e) {
+ throw new PoolingFeatureException("cannot filter topic " + topic);
+ }
+ }
+
+ /**
+ * Publishes a message to the sink.
+ *
+ * @param msg message to be published
+ * @throws PoolingFeatureException if an error occurs or the publisher isn't
+ * running
+ */
+ public void publish(String msg) throws PoolingFeatureException {
+ if (!publishing) {
+ throw new PoolingFeatureException(new IllegalStateException("no topic sink " + topic));
+ }
+
+ try {
+ if (!topicSink.send(msg)) {
+ throw new PoolingFeatureException("failed to send to topic sink " + topic);
+ }
+
+ } catch (IllegalStateException e) {
+ throw new PoolingFeatureException("cannot send to topic sink " + topic, e);
+ }
+ }
+
+ /**
+ * Factory used to construct objects.
+ */
+ public static class Factory {
+
+ /**
+ * Initializes the topic sources.
+ *
+ * @param props properties used to configure the topics
+ * @return the topic sources
+ */
+ public List<TopicSource> initTopicSources(Properties props) {
+ return TopicEndpoint.manager.addTopicSources(props);
+ }
+
+ /**
+ * Initializes the topic sinks.
+ *
+ * @param props properties used to configure the topics
+ * @return the topic sinks
+ */
+ public List<TopicSink> initTopicSinks(Properties props) {
+ return TopicEndpoint.manager.addTopicSinks(props);
+ }
+
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/EventQueue.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/EventQueue.java
new file mode 100644
index 00000000..0bed85b5
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/EventQueue.java
@@ -0,0 +1,121 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.util.Deque;
+import java.util.LinkedList;
+import org.onap.policy.drools.pooling.message.Forward;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Finite queue of events waiting to be processed once the buckets have been
+ * assigned.
+ */
+public class EventQueue {
+
+ private static final Logger logger = LoggerFactory.getLogger(EventQueue.class);
+
+ /**
+ * Maximum number of events allowed in the queue. When excess events are
+ * added, the older events are removed.
+ */
+ private int maxEvents;
+
+ /**
+ * Maximum age, in milliseconds, of events in the queue. Events that are
+ * older than this are discarded rather than being handed off when
+ * {@link #poll()} is invoked.
+ */
+ private long maxAgeMs;
+
+ /**
+ * The actual queue of events.
+ */
+ private Deque<Forward> events = new LinkedList<>();
+
+ /**
+ *
+ * @param maxEvents maximum number of events to hold in the queue
+ * @param maxAgeMs maximum age of events in the queue
+ */
+ public EventQueue(int maxEvents, long maxAgeMs) {
+ this.maxEvents = maxEvents;
+ this.maxAgeMs = maxAgeMs;
+ }
+
+ /**
+ *
+ * @return {@code true} if the queue is empty, {@code false} otherwise
+ */
+ public boolean isEmpty() {
+ return events.isEmpty();
+ }
+
+ /**
+ * Clears the queue.
+ */
+ public void clear() {
+ events.clear();
+ }
+
+ /**
+ *
+ * @return the number of elements in the queue
+ */
+ public int size() {
+ return events.size();
+ }
+
+ /**
+ * Adds an item to the queue. If the queue is full, the older item is
+ * removed and discarded.
+ *
+ * @param event
+ */
+ public void add(Forward event) {
+ if (events.size() >= maxEvents) {
+ logger.warn("full queue - discarded event for topic {}", event.getTopic());
+ events.remove();
+ }
+
+ events.add(event);
+ }
+
+ /**
+ * Gets the oldest, un-expired event from the queue.
+ *
+ * @return the oldest, un-expired event
+ */
+ public Forward poll() {
+ long tmin = System.currentTimeMillis() - maxAgeMs;
+
+ Forward ev;
+ while ((ev = events.poll()) != null) {
+ if (!ev.isExpired(tmin)) {
+ break;
+ }
+ }
+
+ return ev;
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/FeatureEnabledChecker.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/FeatureEnabledChecker.java
new file mode 100644
index 00000000..d2f32043
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/FeatureEnabledChecker.java
@@ -0,0 +1,144 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+// TODO move to policy-utils
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Field;
+import java.util.Properties;
+import org.onap.policy.common.utils.properties.SpecPropertyConfiguration;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+
+/**
+ * Checks whether or not a feature is enabled. The name of the "enable" property
+ * is assumed to be of the form accepted by a {@link SpecPropertyConfiguration},
+ * which contains a substitution place-holder into which a "specializer" (e.g.,
+ * controller or session name) is substituted.
+ */
+public class FeatureEnabledChecker {
+
+ /**
+ *
+ */
+ private FeatureEnabledChecker() {
+ super();
+ }
+
+ /**
+ * Determines if a feature is enabled for a particular specializer.
+ *
+ * @param props properties from which to extract the "enabled" flag
+ * @param specializer specializer to be substituted into the property name
+ * when extracting
+ * @param propName the name of the "enabled" property
+ * @return {@code true} if the feature is enabled, or {@code false} if it is
+ * not enabled (or if the property doesn't exist)
+ * @throws IllegalArgumentException if the "enabled" property is not a
+ * boolean value
+ */
+ public static boolean isFeatureEnabled(Properties props, String specializer, String propName) {
+
+ try {
+ return new Config(specializer, props, propName).isEnabled();
+
+ } catch (PropertyException e) {
+ throw new IllegalArgumentException("cannot check property " + propName, e);
+ }
+ }
+
+
+ /**
+ * Configuration used to extract the value.
+ */
+ private static class Config extends SpecPropertyConfiguration {
+
+ /**
+ * There is a bit of trickery here. This annotation is just a
+ * place-holder to get the superclass to invoke the
+ * {@link #setValue(java.lang.reflect.Field, Properties, Property)
+ * setValue()} method. When that's invoked, we'll substitute
+ * {@link #propOverride} instead of this annotation.
+ */
+ @Property(name = "feature-enabled-property-place-holder")
+ private boolean enabled;
+
+ /**
+ * Annotation that will actually be used to set the field.
+ */
+ private Property propOverride;
+
+ /**
+ *
+ * @param specializer specializer to be substituted into the property
+ * name when extracting
+ * @param props properties from which to extract the "enabled" flag
+ * @param propName the name of the "enabled" property
+ * @throws PropertyException if an error occurs
+ */
+ public Config(String specializer, Properties props, String propName) throws PropertyException {
+ super(specializer);
+
+ propOverride = new Property() {
+
+ @Override
+ public String name() {
+ return propName;
+ }
+
+ @Override
+ public String defaultValue() {
+ // feature is disabled by default
+ return "false";
+ }
+
+ @Override
+ public String accept() {
+ return "";
+ }
+
+ @Override
+ public Class<? extends Annotation> annotationType() {
+ return Property.class;
+ }
+ };
+
+ setAllFields(props);
+ }
+
+ /**
+ * Substitutes {@link #propOverride} for "prop".
+ */
+ @Override
+ protected boolean setValue(Field field, Properties props, Property prop) throws PropertyException {
+ return super.setValue(field, props, propOverride);
+ }
+
+ /**
+ *
+ * @return {@code true} if the feature is enabled, {@code false}
+ * otherwise
+ */
+ public boolean isEnabled() {
+ return enabled;
+ }
+ };
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeature.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeature.java
new file mode 100644
index 00000000..da47a031
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeature.java
@@ -0,0 +1,390 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.io.IOException;
+import java.util.Properties;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+import org.onap.policy.drools.controller.DroolsController;
+import org.onap.policy.drools.core.PolicySessionFeatureAPI;
+import org.onap.policy.drools.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.drools.features.DroolsControllerFeatureAPI;
+import org.onap.policy.drools.features.PolicyControllerFeatureAPI;
+import org.onap.policy.drools.system.PolicyController;
+import org.onap.policy.drools.utils.PropertyUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Controller/session pooling. Multiple hosts may be launched, all servicing the
+ * same controllers/sessions. When this feature is enabled, the requests are
+ * divided across the different hosts, instead of all running on a single,
+ * active host.
+ * <p>
+ * With each controller, there is an associated DMaaP topic that is used for
+ * internal communication between the different hosts serving the controller.
+ */
+public class PoolingFeature implements PolicyControllerFeatureAPI, DroolsControllerFeatureAPI, PolicySessionFeatureAPI {
+
+ private static final Logger logger = LoggerFactory.getLogger(PoolingFeature.class);
+
+ // TODO state-management doesn't allow more than one active host at a time
+
+ /**
+ * Factory used to create objects.
+ */
+ private static Factory factory;
+
+ /**
+ * Entire set of feature properties, including those specific to various
+ * controllers.
+ */
+ private Properties featProps = null;
+
+ /**
+ * Maps a controller name to its associated manager.
+ */
+ private ConcurrentHashMap<String, PoolingManagerImpl> ctlr2pool = new ConcurrentHashMap<>(107);
+
+ /**
+ * Arguments passed to beforeOffer(), which are saved for when the
+ * beforeInsert() is called later. As multiple threads can be active within
+ * the methods at the same time, we must keep this in thread local storage.
+ */
+ private ThreadLocal<OfferArgs> offerArgs = new ThreadLocal<>();
+
+ /**
+ *
+ */
+ public PoolingFeature() {
+ super();
+ }
+
+ protected static Factory getFactory() {
+ return factory;
+ }
+
+ /**
+ * Sets the factory to be used to create objects. Used by junit tests.
+ *
+ * @param factory the new factory to be used to create objects
+ */
+ protected static void setFactory(Factory factory) {
+ PoolingFeature.factory = factory;
+ }
+
+ @Override
+ public int getSequenceNumber() {
+ return 0;
+ }
+
+ /**
+ * @throws PoolingFeatureRtException if the properties cannot be read or are
+ * invalid
+ */
+ @Override
+ public void globalInit(String[] args, String configDir) {
+ logger.info("initializing pooling feature");
+
+ try {
+ featProps = PropertyUtil.getProperties(configDir + "/feature-pooling-dmaap.properties");
+
+ } catch (IOException ex) {
+ throw new PoolingFeatureRtException(ex);
+ }
+ }
+
+ /**
+ * Adds the controller and a new pooling manager to {@link #ctlr2pool}.
+ *
+ * @throws PoolingFeatureRtException if an error occurs
+ */
+ @Override
+ public boolean afterCreate(PolicyController controller) {
+
+ if (featProps == null) {
+ logger.error("pooling feature properties have not been loaded");
+ throw new PoolingFeatureRtException(new IllegalStateException("missing pooling feature properties"));
+ }
+
+ String name = controller.getName();
+
+ if (FeatureEnabledChecker.isFeatureEnabled(featProps, name, PoolingProperties.FEATURE_ENABLED)) {
+ try {
+ // get & validate the properties
+ PoolingProperties props = new PoolingProperties(name, featProps);
+
+ logger.info("pooling enabled for {}", name);
+ ctlr2pool.computeIfAbsent(name, xxx -> factory.makeManager(controller, props));
+
+ } catch (PropertyException e) {
+ logger.error("pooling disabled due to exception for {}", name, e);
+ throw new PoolingFeatureRtException(e);
+ }
+
+ } else {
+ logger.info("pooling disabled for {}", name);
+ }
+
+
+ return false;
+ }
+
+ @Override
+ public boolean beforeStart(PolicyController controller) {
+ return doManager(controller, mgr -> {
+ mgr.beforeStart();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean afterStart(PolicyController controller) {
+ return doManager(controller, mgr -> {
+ mgr.afterStart();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean beforeStop(PolicyController controller) {
+ return doManager(controller, mgr -> {
+ mgr.beforeStop();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean afterStop(PolicyController controller) {
+
+ // NOTE: using doDeleteManager() instead of doManager()
+
+ return doDeleteManager(controller, mgr -> {
+
+ mgr.afterStop();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean beforeLock(PolicyController controller) {
+ return doManager(controller, mgr -> {
+ mgr.beforeLock();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean afterUnlock(PolicyController controller) {
+ return doManager(controller, mgr -> {
+ mgr.afterUnlock();
+ return false;
+ });
+ }
+
+ @Override
+ public boolean beforeOffer(PolicyController controller, CommInfrastructure protocol, String topic2, String event) {
+ /*
+ * As this is invoked a lot, we'll directly call the manager's method
+ * instead of using the functional interface via doManager().
+ */
+ PoolingManagerImpl mgr = ctlr2pool.get(controller.getName());
+ if (mgr == null) {
+ return false;
+ }
+
+ if (mgr.beforeOffer(protocol, topic2, event)) {
+ return true;
+ }
+
+ offerArgs.set(new OfferArgs(protocol, topic2, event));
+ return false;
+ }
+
+ @Override
+ public boolean beforeInsert(DroolsController droolsController, Object fact) {
+
+ OfferArgs args = offerArgs.get();
+ if (args == null) {
+ return false;
+ }
+
+ PolicyController controller;
+ try {
+ controller = factory.getController(droolsController);
+
+ } catch (IllegalArgumentException | IllegalStateException e) {
+ return false;
+ }
+
+ if (controller == null) {
+ return false;
+ }
+
+ /*
+ * As this is invoked a lot, we'll directly call the manager's method
+ * instead of using the functional interface via doManager().
+ */
+ PoolingManagerImpl mgr = ctlr2pool.get(controller.getName());
+ if (mgr == null) {
+ return false;
+ }
+
+ return mgr.beforeInsert(args.protocol, args.topic, args.event, fact);
+ }
+
+ @Override
+ public boolean afterOffer(PolicyController controller, CommInfrastructure protocol, String topic, String event,
+ boolean success) {
+
+ // clear any stored arguments
+ offerArgs.set(null);
+
+ return false;
+ }
+
+ /**
+ * Executes a function using the manager associated with the controller.
+ * Catches any exceptions from the function and re-throws it as a runtime
+ * exception.
+ *
+ * @param controller
+ * @param func function to be executed
+ * @return {@code true} if the function handled the request, {@code false}
+ * otherwise
+ * @throws PoolingFeatureRtException if an error occurs
+ */
+ private boolean doManager(PolicyController controller, MgrFunc func) {
+ PoolingManagerImpl mgr = ctlr2pool.get(controller.getName());
+ if (mgr == null) {
+ return false;
+ }
+
+ try {
+ return func.apply(mgr);
+
+ } catch (PoolingFeatureException e) {
+ throw e.toRuntimeException();
+ }
+ }
+
+ /**
+ * Executes a function using the manager associated with the controller and
+ * then deletes the manager. Catches any exceptions from the function and
+ * re-throws it as a runtime exception.
+ *
+ * @param controller
+ * @param func function to be executed
+ * @return {@code true} if the function handled the request, {@code false}
+ * otherwise
+ * @throws PoolingFeatureRtException if an error occurs
+ */
+ private boolean doDeleteManager(PolicyController controller, Function<PoolingManagerImpl, Boolean> func) {
+
+ // NOTE: using "remove()" instead of "get()"
+
+ PoolingManagerImpl mgr = ctlr2pool.remove(controller.getName());
+
+ if (mgr == null) {
+ return false;
+ }
+
+ return func.apply(mgr);
+ }
+
+ /**
+ * Function that operates on a manager.
+ */
+ @FunctionalInterface
+ private static interface MgrFunc {
+
+ /**
+ *
+ * @param mgr
+ * @return {@code true} if the request was handled by the manager,
+ * {@code false} otherwise
+ * @throws PoolingFeatureException
+ */
+ public boolean apply(PoolingManagerImpl mgr) throws PoolingFeatureException;
+ }
+
+ /**
+ * Arguments captured from beforeOffer().
+ */
+ private static class OfferArgs {
+
+ /**
+ * Protocol of the receiving topic.
+ */
+ private CommInfrastructure protocol;
+
+ /**
+ * Topic on which the event was received.
+ */
+ private String topic;
+
+ /**
+ * The event text that was received on the topic.
+ */
+ private String event;
+
+ /**
+ *
+ * @param protocol
+ * @param topic
+ * @param event the actual event data received on the topic
+ */
+ public OfferArgs(CommInfrastructure protocol, String topic, String event) {
+ this.protocol = protocol;
+ this.topic = topic;
+ this.event = event;
+ }
+ }
+
+ /**
+ * Used to create objects.
+ */
+ public static class Factory {
+
+ /**
+ * Makes a pooling manager for a controller.
+ *
+ * @param controller
+ * @param props properties to use to configure the manager
+ * @return a new pooling manager
+ */
+ public PoolingManagerImpl makeManager(PolicyController controller, PoolingProperties props) {
+ return new PoolingManagerImpl(controller, props);
+ }
+
+ /**
+ * Gets the policy controller associated with a drools controller.
+ *
+ * @param droolsController
+ * @return the policy controller associated with a drools controller
+ */
+ public PolicyController getController(DroolsController droolsController) {
+ return PolicyController.factory.get(droolsController);
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureException.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureException.java
new file mode 100644
index 00000000..5efd1414
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureException.java
@@ -0,0 +1,59 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+/**
+ * Exception thrown by the pooling feature.
+ */
+public class PoolingFeatureException extends Exception {
+ private static final long serialVersionUID = 1L;
+
+ public PoolingFeatureException() {
+ super();
+ }
+
+ public PoolingFeatureException(String message) {
+ super(message);
+ }
+
+ public PoolingFeatureException(Throwable cause) {
+ super(cause);
+ }
+
+ public PoolingFeatureException(String message, Throwable cause) {
+ super(message, cause);
+ }
+
+ public PoolingFeatureException(String message, Throwable cause, boolean enableSuppression,
+ boolean writableStackTrace) {
+ super(message, cause, enableSuppression, writableStackTrace);
+ }
+
+ /**
+ * Converts the exception to a runtime exception.
+ *
+ * @return a new runtime exception, wrapping this exception
+ */
+ public PoolingFeatureRtException toRuntimeException() {
+ return new PoolingFeatureRtException(this);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureRtException.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureRtException.java
new file mode 100644
index 00000000..6fdb6c69
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingFeatureRtException.java
@@ -0,0 +1,50 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+/**
+ * A runtime exception thrown by the pooling feature.
+ */
+public class PoolingFeatureRtException extends RuntimeException {
+ private static final long serialVersionUID = 1L;
+
+ public PoolingFeatureRtException() {
+ super();
+ }
+
+ public PoolingFeatureRtException(String message) {
+ super(message);
+ }
+
+ public PoolingFeatureRtException(Throwable cause) {
+ super(cause);
+ }
+
+ public PoolingFeatureRtException(String message, Throwable cause) {
+ super(message, cause);
+ }
+
+ public PoolingFeatureRtException(String message, Throwable cause, boolean enableSuppression,
+ boolean writableStackTrace) {
+ super(message, cause, enableSuppression, writableStackTrace);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManager.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManager.java
new file mode 100644
index 00000000..de08d1e1
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManager.java
@@ -0,0 +1,152 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ScheduledFuture;
+import org.onap.policy.drools.pooling.message.BucketAssignments;
+import org.onap.policy.drools.pooling.message.Forward;
+import org.onap.policy.drools.pooling.message.Message;
+import org.onap.policy.drools.pooling.state.State;
+import org.onap.policy.drools.pooling.state.StateTimerTask;
+
+/**
+ * Pooling manager for a single PolicyController.
+ */
+public interface PoolingManager {
+
+ /**
+ * Gets the properties used to configure the manager.
+ *
+ * @return
+ */
+ public PoolingProperties getProperties();
+
+ /**
+ * Gets the host id.
+ *
+ * @return the host id
+ */
+ public String getHost();
+
+ /**
+ * Gets the name of the internal DMaaP topic used by this manager to
+ * communicate with its other hosts.
+ *
+ * @return the name of the internal DMaaP topic
+ */
+ public String getTopic();
+
+ /**
+ * Indicates that communication with internal DMaaP topic failed, typically
+ * due to a missed heart beat. Stops the PolicyController.
+ *
+ * @return a latch that can be used to determine when the controller's
+ * stop() method has completed
+ */
+ public CountDownLatch internalTopicFailed();
+
+ /**
+ * Starts distributing requests according to the given bucket assignments.
+ *
+ * @param assignments must <i>not</i> be {@code null}
+ */
+ public void startDistributing(BucketAssignments assignments);
+
+ /**
+ * Gets the current bucket assignments.
+ *
+ * @return the current bucket assignments, or {@code null} if no assignments
+ * have been made
+ */
+ public BucketAssignments getAssignments();
+
+ /**
+ * Publishes a message to the internal topic on the administrative channel.
+ *
+ * @param msg message to be published
+ */
+ public void publishAdmin(Message msg);
+
+ /**
+ * Publishes a message to the internal topic on a particular channel.
+ *
+ * @param channel channel on which the message should be published
+ * @param msg message to be published
+ */
+ public void publish(String channel, Message msg);
+
+ /**
+ * Handles a {@link Forward} event that was received from the internal
+ * topic.
+ *
+ * @param event
+ */
+ public void handle(Forward event);
+
+ /**
+ * Schedules a timer to fire after a delay.
+ *
+ * @param delayMs delay, in milliseconds
+ * @param task
+ * @return a future that can be used to cancel the timer
+ */
+ public ScheduledFuture<?> schedule(long delayMs, StateTimerTask task);
+
+ /**
+ * Schedules a timer to fire repeatedly.
+ *
+ * @param initialDelayMs initial delay, in milliseconds
+ * @param delayMs delay, in milliseconds
+ * @param task
+ * @return a future that can be used to cancel the timer
+ */
+ public ScheduledFuture<?> scheduleWithFixedDelay(long initialDelayMs, long delayMs, StateTimerTask task);
+
+ /**
+ * Transitions to the "start" state.
+ *
+ * @return the new state
+ */
+ public State goStart();
+
+ /**
+ * Transitions to the "query" state.
+ *
+ * @return the new state
+ */
+ public State goQuery();
+
+ /**
+ * Transitions to the "active" state.
+ *
+ * @return the new state
+ */
+ public State goActive();
+
+ /**
+ * Transitions to the "inactive" state.
+ *
+ * @return the new state
+ */
+ public State goInactive();
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManagerImpl.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManagerImpl.java
new file mode 100644
index 00000000..cd71670d
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingManagerImpl.java
@@ -0,0 +1,871 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.Properties;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import org.onap.policy.drools.controller.DroolsController;
+import org.onap.policy.drools.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.drools.event.comm.TopicListener;
+import org.onap.policy.drools.pooling.extractor.ClassExtractors;
+import org.onap.policy.drools.pooling.message.BucketAssignments;
+import org.onap.policy.drools.pooling.message.Forward;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Message;
+import org.onap.policy.drools.pooling.state.ActiveState;
+import org.onap.policy.drools.pooling.state.IdleState;
+import org.onap.policy.drools.pooling.state.InactiveState;
+import org.onap.policy.drools.pooling.state.QueryState;
+import org.onap.policy.drools.pooling.state.StartState;
+import org.onap.policy.drools.pooling.state.State;
+import org.onap.policy.drools.pooling.state.StateTimerTask;
+import org.onap.policy.drools.protocol.coders.EventProtocolCoder;
+import org.onap.policy.drools.system.PolicyController;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+/**
+ * Implementation of a {@link PoolingManager}. Until bucket assignments have
+ * been made, events coming from external topics are saved in a queue for later
+ * processing. Once assignments are made, the saved events are processed. In
+ * addition, while the controller is locked, events are still forwarded to other
+ * hosts and bucket assignments are still updated, based on any {@link Leader}
+ * messages that it receives.
+ */
+public class PoolingManagerImpl implements PoolingManager, TopicListener {
+
+ private static final Logger logger = LoggerFactory.getLogger(PoolingManagerImpl.class);
+
+ // TODO metrics, audit logging
+
+ /**
+ * Maximum number of times a message can be forwarded.
+ */
+ public static final int MAX_HOPS = 5;
+
+ /**
+ * Type of item that the extractors will be extracting.
+ */
+ private static final String EXTRACTOR_TYPE = "requestId";
+
+ /**
+ * Prefix for extractor properties.
+ */
+ private static final String PROP_EXTRACTOR_PREFIX = "extractor." + EXTRACTOR_TYPE;
+
+ /**
+ * Factory used to create various objects. Can be overridden during junit
+ * testing.
+ */
+ private static Factory factory = new Factory();
+
+ /**
+ * ID of this host.
+ */
+ private final String host;
+
+ /**
+ * Properties with which this was configured.
+ */
+ private final PoolingProperties props;
+
+ /**
+ * Associated controller.
+ */
+ private final PolicyController controller;
+
+ /**
+ * Where to offer events that have been forwarded to this host (i.e, the
+ * controller).
+ */
+ private final TopicListener listener;
+
+ /**
+ * Used to encode & decode request objects received from & sent to a rule
+ * engine.
+ */
+ private final Serializer serializer;
+
+ /**
+ * Internal DMaaP topic used by this controller.
+ */
+ private final String topic;
+
+ /**
+ * Manager for the internal DMaaP topic.
+ */
+ private final DmaapManager dmaapMgr;
+
+ /**
+ * Used to extract the request id from the decoded message.
+ */
+ private final ClassExtractors extractors;
+
+ /**
+ * Lock used while updating {@link #current}. In general, public methods
+ * must use this, while private methods assume the lock is already held.
+ */
+ private final Object curLocker = new Object();
+
+ /**
+ * Current state.
+ * <p>
+ * This uses a finite state machine, wherein the state object contains all
+ * of the data relevant to that state. Each state object has a process()
+ * method, specific to each type of {@link Message} subclass. The method
+ * returns the next state object, or {@code null} if the state is to remain
+ * the same.
+ */
+ private State current;
+
+ /**
+ * Current bucket assignments or {@code null}.
+ */
+ private BucketAssignments assignments = null;
+
+ /**
+ * Pool used to execute timers.
+ */
+ private ScheduledThreadPoolExecutor scheduler = null;
+
+ /**
+ * Queue used when no bucket assignments are available.
+ */
+ private EventQueue eventq;
+
+ /**
+ * {@code True} if events offered by the controller should be intercepted,
+ * {@code false} otherwise.
+ */
+ private boolean intercept = true;
+
+ /**
+ * Constructs the manager, initializing all of the data structures.
+ *
+ * @param controller controller with which this is associated
+ * @param props feature properties specific to the controller
+ */
+ public PoolingManagerImpl(PolicyController controller, PoolingProperties props) {
+ this.host = UUID.randomUUID().toString();
+ this.controller = controller;
+ this.props = props;
+
+ try {
+ this.listener = (TopicListener) controller;
+ this.serializer = new Serializer();
+ this.topic = props.getPoolingTopic();
+ this.eventq = factory.makeEventQueue(props);
+
+ SpecProperties spec = new SpecProperties(PROP_EXTRACTOR_PREFIX, controller.getName());
+ this.extractors = factory.makeClassExtractors(spec);
+
+ this.dmaapMgr = factory.makeDmaapManager(props);
+ this.current = new IdleState(this);
+
+ logger.info("allocating host {} to controller {} for topic {}", host, controller.getName(), topic);
+
+ } catch (ClassCastException e) {
+ logger.error("not a topic listener, controller {}", controller.getName());
+ throw new PoolingFeatureRtException(e);
+
+ } catch (PoolingFeatureException e) {
+ logger.error("failed to attach internal DMaaP topic to controller {}", controller.getName());
+ throw e.toRuntimeException();
+ }
+ }
+
+ protected static Factory getFactory() {
+ return factory;
+ }
+
+ protected static void setFactory(Factory factory) {
+ PoolingManagerImpl.factory = factory;
+ }
+
+ /**
+ * Should only be used by junit tests.
+ *
+ * @return the current state
+ */
+ protected State getCurrent() {
+ synchronized (curLocker) {
+ return current;
+ }
+ }
+
+ public String getHost() {
+ return host;
+ }
+
+ public String getTopic() {
+ return topic;
+ }
+
+ @Override
+ public PoolingProperties getProperties() {
+ return props;
+ }
+
+ /**
+ * Indicates that the controller is about to start. Starts the publisher for
+ * the internal topic, and creates a thread pool for the timers.
+ *
+ * @throws PoolingFeatureException if the internal topic publisher cannot be
+ * started
+ */
+ public void beforeStart() throws PoolingFeatureException {
+ synchronized (curLocker) {
+ if (scheduler == null) {
+ dmaapMgr.startPublisher();
+
+ scheduler = factory.makeScheduler();
+
+ /*
+ * Only a handful of timers at any moment, thus we can afford to
+ * take the time to remove them when they're cancelled.
+ */
+ scheduler.setRemoveOnCancelPolicy(true);
+ scheduler.setMaximumPoolSize(1);
+ scheduler.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
+ scheduler.setContinueExistingPeriodicTasksAfterShutdownPolicy(false);
+ }
+ }
+ }
+
+ /**
+ * Indicates that the controller has successfully started. Starts the
+ * consumer for the internal topic, enters the {@link StartState}, and sets
+ * the filter for the initial state.
+ */
+ public void afterStart() {
+ synchronized (curLocker) {
+ if (current instanceof IdleState) {
+ dmaapMgr.startConsumer(this);
+ changeState(new StartState(this));
+ }
+ }
+ }
+
+ /**
+ * Indicates that the controller is about to stop. Stops the consumer, the
+ * scheduler, and the current state.
+ */
+ public void beforeStop() {
+ ScheduledThreadPoolExecutor sched;
+
+ synchronized (curLocker) {
+ sched = scheduler;
+ scheduler = null;
+
+ if (!(current instanceof IdleState)) {
+ dmaapMgr.stopConsumer(this);
+ changeState(new IdleState(this));
+
+ // TODO
+ /*
+ * Need a brief delay here to allow "offline" message to be
+ * transmitted?
+ */
+ }
+ }
+
+ if (sched != null) {
+ sched.shutdownNow();
+ }
+ }
+
+ /**
+ * Indicates that the controller has stopped. Stops the publisher and logs a
+ * warning if any events are still in the queue.
+ */
+ public void afterStop() {
+ synchronized (curLocker) {
+ if (!eventq.isEmpty()) {
+ logger.warn("discarded {} messages after stopping topic {}", eventq.size(), topic);
+ eventq.clear();
+ }
+
+ dmaapMgr.stopPublisher();
+ }
+ }
+
+ /**
+ * Indicates that the controller is about to be locked. Enters the idle
+ * state, as all it will be doing is forwarding messages.
+ */
+ public void beforeLock() {
+ synchronized (curLocker) {
+ changeState(new IdleState(this));
+ }
+ }
+
+ /**
+ * Indicates that the controller has been unlocked. Enters the start state,
+ * if the controller is running.
+ */
+ public void afterUnlock() {
+ synchronized (curLocker) {
+ if (controller.isAlive() && current instanceof IdleState && scheduler != null) {
+ changeState(new StartState(this));
+ }
+ }
+ }
+
+ /**
+ * Changes the finite state machine to a new state, provided the new state
+ * is not {@code null}.
+ *
+ * @param newState new state, or {@code null} if to remain unchanged
+ */
+ private void changeState(State newState) {
+ if (newState != null) {
+ current.cancelTimers();
+ current = newState;
+
+ // set the filter before starting the state
+ setFilter(newState.getFilter());
+ newState.start();
+ }
+ }
+
+ /**
+ * Sets the server-side filter for the internal topic.
+ *
+ * @param filter new filter to be used
+ */
+ private void setFilter(Map<String, Object> filter) {
+ try {
+ dmaapMgr.setFilter(serializer.encodeFilter(filter));
+
+ } catch (JsonProcessingException e) {
+ logger.error("failed to encode server-side filter for topic {}, {}", topic, filter, e);
+
+ } catch (PoolingFeatureException e) {
+ logger.error("failed to set server-side filter for topic {}, {}", topic, filter, e);
+ }
+ }
+
+ @Override
+ public CountDownLatch internalTopicFailed() {
+ logger.error("communication failed for topic {}", topic);
+
+ CountDownLatch latch = new CountDownLatch(1);
+
+ /*
+ * We don't want to build up items in our queue if we can't forward them
+ * to other hosts, so we just stop the controller.
+ *
+ * Use a background thread to prevent deadlocks.
+ */
+ new Thread() {
+ @Override
+ public void run() {
+ controller.stop();
+ latch.countDown();
+ }
+ }.start();
+
+ return latch;
+ }
+
+ @Override
+ public ScheduledFuture<?> schedule(long delayMs, StateTimerTask task) {
+ return scheduler.schedule(new TimerAction(task), delayMs, TimeUnit.MILLISECONDS);
+ }
+
+ @Override
+ public ScheduledFuture<?> scheduleWithFixedDelay(long initialDelayMs, long delayMs, StateTimerTask task) {
+ return scheduler.scheduleWithFixedDelay(new TimerAction(task), initialDelayMs, delayMs, TimeUnit.MILLISECONDS);
+ }
+
+ @Override
+ public void publishAdmin(Message msg) {
+ publish(Message.ADMIN, msg);
+ }
+
+ @Override
+ public void publish(String channel, Message msg) {
+ msg.setChannel(channel);
+
+ try {
+ // ensure it's valid before we send it
+ msg.checkValidity();
+
+ String txt = serializer.encodeMsg(msg);
+ dmaapMgr.publish(txt);
+
+ } catch (JsonProcessingException e) {
+ logger.error("failed to serialize message for topic {} channel {}", topic, channel, e);
+
+ } catch (PoolingFeatureException e) {
+ logger.error("failed to publish message for topic {} channel {}", topic, channel, e);
+ }
+ }
+
+ /**
+ * Handles an event from the internal topic.
+ *
+ * @param topic2
+ * @param event
+ * @return {@code true} if the event was handled, {@code false} if the
+ * controller should handle it
+ */
+ @Override
+ public void onTopicEvent(CommInfrastructure commType, String topic2, String event) {
+
+ if (event == null) {
+ logger.error("null event on topic {}", topic);
+ return;
+ }
+
+ synchronized (curLocker) {
+ // it's on the internal topic
+ handleInternal(event);
+ }
+ }
+
+ /**
+ * Called by the PolicyController before it offers the event to the
+ * DroolsController. If the controller is locked, then it isn't processing
+ * events. However, they still need to be forwarded, thus in that case, they
+ * are decoded and forwarded.
+ * <p>
+ * On the other hand, if the controller is not locked, then we just return
+ * immediately and let {@link #beforeInsert(Object, String, String, Object)
+ * beforeInsert()} handle it instead, as it already has the decoded message.
+ *
+ * @param protocol
+ * @param topic2
+ * @param event
+ * @return {@code true} if the event was handled by the manager,
+ * {@code false} if it must still be handled by the invoker
+ */
+ public boolean beforeOffer(CommInfrastructure protocol, String topic2, String event) {
+
+ if (!controller.isLocked() || !intercept) {
+ // we should NOT intercept this message - let the invoker handle it
+ return false;
+ }
+
+ return handleExternal(protocol, topic2, event, extractRequestId(decodeEvent(topic2, event)));
+ }
+
+ /**
+ * Called by the DroolsController before it inserts the event into the rule
+ * engine.
+ *
+ * @param protocol
+ * @param topic2
+ * @param event original event text, as received from the Bus
+ * @param event2 event, as an object
+ * @return {@code true} if the event was handled by the manager,
+ * {@code false} if it must still be handled by the invoker
+ */
+ public boolean beforeInsert(CommInfrastructure protocol, String topic2, String event, Object event2) {
+
+ if (!intercept) {
+ // we should NOT intercept this message - let the invoker handle it
+ return false;
+ }
+
+ return handleExternal(protocol, topic2, event, extractRequestId(event2));
+ }
+
+ /**
+ * Handles an event from an external topic.
+ *
+ * @param protocol
+ * @param topic2
+ * @param event
+ * @param reqid request id extracted from the event, or {@code null} if it
+ * couldn't be extracted
+ * @return {@code true} if the event was handled by the manager,
+ * {@code false} if it must still be handled by the invoker
+ */
+ private boolean handleExternal(CommInfrastructure protocol, String topic2, String event, String reqid) {
+ if (reqid == null) {
+ // no request id - let the invoker handle it
+ return false;
+ }
+
+ if (reqid.isEmpty()) {
+ logger.warn("handle locally due to empty request id for topic {}", topic2);
+ // no request id - let the invoker handle it
+ return false;
+ }
+
+ Forward ev = makeForward(protocol, topic2, event, reqid);
+ if (ev == null) {
+ // invalid args - consume the message
+ return true;
+ }
+
+ synchronized (curLocker) {
+ return handleExternal(ev);
+ }
+ }
+
+ /**
+ * Handles an event from an external topic.
+ *
+ * @param event
+ * @return {@code true} if the event was handled, {@code false} if the
+ * invoker should handle it
+ */
+ private boolean handleExternal(Forward event) {
+ if (assignments == null) {
+ // no bucket assignments yet - add it to the queue
+ eventq.add(event);
+
+ // we've consumed the event
+ return true;
+
+ } else {
+ return handleEvent(event);
+ }
+ }
+
+ /**
+ * Handles a {@link Forward} event, possibly forwarding it again.
+ *
+ * @param event
+ * @return {@code true} if the event was handled, {@code false} if the
+ * invoker should handle it
+ */
+ private boolean handleEvent(Forward event) {
+ int bucket = Math.abs(event.getRequestId().hashCode()) % assignments.size();
+ String target = assignments.getAssignedHost(bucket);
+
+ if (target == null) {
+ /*
+ * This bucket has no assignment - just discard the event
+ */
+ return true;
+ }
+
+ if (target.equals(host)) {
+ /*
+ * Message belongs to this host - allow the controller to handle it.
+ */
+ return false;
+ }
+
+ // forward to a different host, if hop count has been exhausted
+ if (event.getNumHops() > MAX_HOPS) {
+ logger.warn("message discarded - hop count {} exceeded {} for topic {}", event.getNumHops(), MAX_HOPS,
+ topic);
+
+ } else {
+ event.bumpNumHops();
+ publish(target, event);
+ }
+
+ // either way, consume the event
+ return true;
+ }
+
+ /**
+ * Extract the request id from an event object.
+ *
+ * @param event the event object, or {@code null}
+ * @return the event's request id, or {@code null} if it can't be extracted
+ */
+ private String extractRequestId(Object event) {
+ if (event == null) {
+ return null;
+ }
+
+ Object reqid = extractors.extract(event);
+ return (reqid != null ? reqid.toString() : null);
+ }
+
+ /**
+ * Decodes an event from a String into an event Object.
+ *
+ * @param topic2
+ * @param event
+ * @return the decoded event object, or {@code null} if it can't be decoded
+ */
+ private Object decodeEvent(String topic2, String event) {
+ DroolsController drools = controller.getDrools();
+
+ // check if this topic has a decoder
+
+ if (!factory.canDecodeEvent(drools, topic2)) {
+
+ logger.warn("{}: DECODING-UNSUPPORTED {}:{}:{}", drools, topic2, drools.getGroupId(),
+ drools.getArtifactId());
+ return null;
+ }
+
+ // decode
+
+ try {
+ return factory.decodeEvent(drools, topic2, event);
+
+ } catch (UnsupportedOperationException | IllegalStateException | IllegalArgumentException e) {
+ logger.debug("{}: DECODE FAILED: {} <- {} because of {}", drools, topic2, event, e.getMessage(), e);
+ return null;
+ }
+ }
+
+ /**
+ * Makes a {@link Forward}, and validates its contents.
+ *
+ * @param protocol
+ * @param topic2
+ * @param event
+ * @param reqid
+ * @return a new message, or {@code null} if the message was invalid
+ */
+ private Forward makeForward(CommInfrastructure protocol, String topic2, String event, String reqid) {
+ try {
+ Forward ev = new Forward(host, protocol, topic2, event, reqid);
+
+ // required for the validity check
+ ev.setChannel(host);
+
+ ev.checkValidity();
+
+ return ev;
+
+ } catch (PoolingFeatureException e) {
+ logger.error("invalid message for topic {}", topic2, e);
+ return null;
+ }
+ }
+
+ @Override
+ public void handle(Forward event) {
+ synchronized (curLocker) {
+ if (!handleExternal(event)) {
+ // this host should handle it - inject it
+ inject(event);
+ }
+ }
+ }
+
+ /**
+ * Injects an event into the controller.
+ *
+ * @param event
+ */
+ private void inject(Forward event) {
+ intercept = false;
+ listener.onTopicEvent(event.getProtocol(), event.getTopic(), event.getPayload());
+
+ intercept = true;
+ }
+
+ /**
+ * Handles an event from the internal topic. This uses reflection to
+ * identify the appropriate process() method to invoke, based on the type of
+ * Message that was decoded.
+ *
+ * @param event the serialized {@link Message} read from the internal topic
+ */
+ private void handleInternal(String event) {
+ Class<?> clazz = null;
+
+ try {
+ Message msg = serializer.decodeMsg(event);
+
+ // get the class BEFORE checking the validity
+ clazz = msg.getClass();
+
+ msg.checkValidity();
+
+ Method meth = current.getClass().getMethod("process", msg.getClass());
+ changeState((State) meth.invoke(current, msg));
+
+ } catch (IOException e) {
+ logger.warn("failed to decode message for topic {}", topic, e);
+
+ } catch (NoSuchMethodException | SecurityException e) {
+ logger.error("no processor for message {} for topic {}", clazz, topic, e);
+
+ } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+ logger.error("failed to process message {} for topic {}", clazz, topic, e);
+
+ } catch (PoolingFeatureException e) {
+ logger.error("failed to process message {} for topic {}", clazz, topic, e);
+ }
+ }
+
+ @Override
+ public void startDistributing(BucketAssignments assignments) {
+ if (assignments == null) {
+ return;
+ }
+
+ synchronized (curLocker) {
+ this.assignments = assignments;
+
+ // now that we have assignments, we can process the queue
+ Forward ev;
+ while ((ev = eventq.poll()) != null) {
+ handle(ev);
+ }
+ }
+ }
+
+ @Override
+ public BucketAssignments getAssignments() {
+ return assignments;
+ }
+
+ @Override
+ public State goStart() {
+ return new StartState(this);
+ }
+
+ @Override
+ public State goQuery() {
+ return new QueryState(this);
+ }
+
+ @Override
+ public State goActive() {
+ return new ActiveState(this);
+ }
+
+ @Override
+ public State goInactive() {
+ return new InactiveState(this);
+ }
+
+ /**
+ * Action to run a timer task. Only runs the task if the machine is still in
+ * the state that it was in when the timer was created.
+ */
+ private class TimerAction implements Runnable {
+
+ /**
+ * State of the machine when the timer was created.
+ */
+ private State origState;
+
+ /**
+ * Task to be executed.
+ */
+ private StateTimerTask task;
+
+ /**
+ *
+ * @param task task to execute when this timer runs
+ */
+ public TimerAction(StateTimerTask task) {
+ this.origState = current;
+ this.task = task;
+ }
+
+ @Override
+ public void run() {
+ synchronized (curLocker) {
+ if (current == origState) {
+ changeState(task.fire(null));
+ }
+ }
+ }
+ }
+
+ /**
+ * Factory used to create objects.
+ */
+ public static class Factory {
+
+ /**
+ * Creates an event queue.
+ *
+ * @param props properties used to configure the event queue
+ * @return a new event queue
+ */
+ public EventQueue makeEventQueue(PoolingProperties props) {
+ return new EventQueue(props.getOfflineLimit(), props.getOfflineAgeMs());
+ }
+
+ /**
+ * Creates object extractors.
+ *
+ * @param props properties used to configure the extractors
+ * @return a new set of extractors
+ */
+ public ClassExtractors makeClassExtractors(Properties props) {
+ return new ClassExtractors(props, PROP_EXTRACTOR_PREFIX, EXTRACTOR_TYPE);
+ }
+
+ /**
+ * Creates a DMaaP manager.
+ *
+ * @param props properties used to configure the manager
+ * @return a new DMaaP manager
+ * @throws PoolingFeatureException if an error occurs
+ */
+ public DmaapManager makeDmaapManager(PoolingProperties props) throws PoolingFeatureException {
+ return new DmaapManager(props.getPoolingTopic(), props.getSource());
+ }
+
+ /**
+ * Creates a scheduled thread pool.
+ *
+ * @return a new scheduled thread pool
+ */
+ public ScheduledThreadPoolExecutor makeScheduler() {
+ return new ScheduledThreadPoolExecutor(1);
+ }
+
+ /**
+ * Determines if the event can be decoded.
+ *
+ * @param drools drools controller
+ * @param topic topic on which the event was received
+ * @return {@code true} if the event can be decoded, {@code false}
+ * otherwise
+ */
+ public boolean canDecodeEvent(DroolsController drools, String topic) {
+ return EventProtocolCoder.manager.isDecodingSupported(drools.getGroupId(), drools.getArtifactId(), topic);
+ }
+
+ /**
+ * Decodes the event.
+ *
+ * @param drools drools controller
+ * @param topic topic on which the event was received
+ * @param event event text to be decoded
+ * @return the decoded event
+ * @throws IllegalArgumentException
+ * @throw UnsupportedOperationException
+ * @throws IllegalStateException
+ */
+ public Object decodeEvent(DroolsController drools, String topic, String event) {
+ return EventProtocolCoder.manager.decode(drools.getGroupId(), drools.getArtifactId(), topic, event);
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingProperties.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingProperties.java
new file mode 100644
index 00000000..1cbe5cb9
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/PoolingProperties.java
@@ -0,0 +1,162 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.util.Properties;
+import org.onap.policy.common.utils.properties.SpecPropertyConfiguration;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+
+/**
+ * Properties used by the pooling feature, specific to a controller.
+ */
+public class PoolingProperties extends SpecPropertyConfiguration {
+
+ /**
+ * Feature properties all begin with this prefix.
+ */
+ public static final String PREFIX = "pooling.";
+
+ /*
+ * These properties REQUIRE a controller name, thus they use the "{$}" form.
+ */
+ public static final String POOLING_TOPIC = PREFIX + "{$}.topic";
+
+ /*
+ * These properties allow the controller name to be left out, thus they use
+ * the "{prefix?suffix}" form.
+ */
+ public static final String FEATURE_ENABLED = PREFIX + "{?.}enabled";
+ public static final String OFFLINE_LIMIT = PREFIX + "{?.}offline.queue.limit";
+ public static final String OFFLINE_AGE_MS = PREFIX + "{?.}offline.queue.age.milliseconds";
+ public static final String START_HEARTBEAT_MS = PREFIX + "{?.}start.heartbeat.milliseconds";
+ public static final String REACTIVATE_MS = PREFIX + "{?.}reactivate.milliseconds";
+ public static final String IDENTIFICATION_MS = PREFIX + "{?.}identification.milliseconds";
+ public static final String ACTIVE_HEARTBEAT_MS = PREFIX + "{?.}active.heartbeat.milliseconds";
+ public static final String INTER_HEARTBEAT_MS = PREFIX + "{?.}inter.heartbeat.milliseconds";
+
+ /**
+ * Properties from which this was constructed.
+ */
+ private Properties source;
+
+ /**
+ * Topic used for inter-host communication.
+ */
+ @Property(name = POOLING_TOPIC)
+ private String poolingTopic;
+
+ /**
+ * Maximum number of events to retain in the queue while waiting for
+ * buckets to be assigned.
+ */
+ @Property(name = OFFLINE_LIMIT, defaultValue = "1000")
+ private int offlineLimit;
+
+ /**
+ * Maximum age, in milliseconds, of events to be retained in the queue.
+ * Events older than this are discarded.
+ */
+ @Property(name = OFFLINE_AGE_MS, defaultValue = "60000")
+ private long offlineAgeMs;
+
+ /**
+ * Time, in milliseconds, to wait for this host's heart beat during the
+ * start-up state.
+ */
+ @Property(name = START_HEARTBEAT_MS, defaultValue = "50000")
+ private long startHeartbeatMs;
+
+ /**
+ * Time, in milliseconds, to wait before attempting to re-active this
+ * host when it has no bucket assignments.
+ */
+ @Property(name = REACTIVATE_MS, defaultValue = "50000")
+ private long reactivateMs;
+
+ /**
+ * Time, in milliseconds, to wait for all Identification messages to
+ * arrive during the query state.
+ */
+ @Property(name = IDENTIFICATION_MS, defaultValue = "50000")
+ private long identificationMs;
+
+ /**
+ * Time, in milliseconds, to wait for heart beats from this host, or its
+ * predecessor, during the active state.
+ */
+ @Property(name = ACTIVE_HEARTBEAT_MS, defaultValue = "50000")
+ private long activeHeartbeatMs;
+
+ /**
+ * Time, in milliseconds, to wait between heart beat generations during
+ * the active state.
+ */
+ @Property(name = INTER_HEARTBEAT_MS, defaultValue = "15000")
+ private long interHeartbeatMs;
+
+ /**
+ * @param controllerName the name of the controller
+ * @param props set of properties used to configure this
+ * @throws PropertyException if an error occurs
+ *
+ */
+ public PoolingProperties(String controllerName, Properties props) throws PropertyException {
+ super(controllerName, props);
+
+ source = props;
+ }
+
+ public Properties getSource() {
+ return source;
+ }
+
+ public String getPoolingTopic() {
+ return poolingTopic;
+ }
+
+ public int getOfflineLimit() {
+ return offlineLimit;
+ }
+
+ public long getOfflineAgeMs() {
+ return offlineAgeMs;
+ }
+
+ public long getStartHeartbeatMs() {
+ return startHeartbeatMs;
+ }
+
+ public long getReactivateMs() {
+ return reactivateMs;
+ }
+
+ public long getIdentificationMs() {
+ return identificationMs;
+ }
+
+ public long getActiveHeartbeatMs() {
+ return activeHeartbeatMs;
+ }
+
+ public long getInterHeartbeatMs() {
+ return interHeartbeatMs;
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/Serializer.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/Serializer.java
new file mode 100644
index 00000000..63aefb7a
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/Serializer.java
@@ -0,0 +1,79 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.io.IOException;
+import java.util.Map;
+import org.onap.policy.drools.pooling.message.Message;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Serialization helper functions.
+ */
+public class Serializer {
+
+ /**
+ * Used to encode & decode JSON messages sent & received, respectively, on
+ * the internal DMaaP topic.
+ */
+ private final ObjectMapper mapper = new ObjectMapper();
+
+ /**
+ *
+ */
+ public Serializer() {
+ super();
+ }
+
+ /**
+ * Encodes a filter.
+ *
+ * @param filter filter to be encoded
+ * @return the filter, serialized as a JSON string
+ * @throws JsonProcessingException if it cannot be serialized
+ */
+ public String encodeFilter(Map<String, Object> filter) throws JsonProcessingException {
+ return mapper.writeValueAsString(filter);
+ }
+
+ /**
+ * Encodes a message.
+ *
+ * @param msg message to be encoded
+ * @return the message, serialized as a JSON string
+ * @throws JsonProcessingException if it cannot be serialized
+ */
+ public String encodeMsg(Message msg) throws JsonProcessingException {
+ return mapper.writeValueAsString(msg);
+ }
+
+ /**
+ * Decodes a JSON string into a Message.
+ *
+ * @param msg JSON string representing the message
+ * @return the message
+ * @throws IOException if it cannot be serialized
+ */
+ public Message decodeMsg(String msg) throws IOException {
+ return mapper.readValue(msg, Message.class);
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/SpecProperties.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/SpecProperties.java
new file mode 100644
index 00000000..e4557404
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/SpecProperties.java
@@ -0,0 +1,109 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling;
+
+import java.util.Properties;
+
+/**
+ * Properties with an optional specialization (e.g., session name, controller
+ * name).
+ */
+public class SpecProperties extends Properties {
+ private static final long serialVersionUID = 1L;
+
+ /**
+ * The property prefix, ending with ".".
+ */
+ private final String prefix;
+
+ /**
+ * The specialized property prefix, ending with ".".
+ */
+ private final String specPrefix;
+
+ /**
+ *
+ * @param prefix the property name prefix that appears before any
+ * specialization
+ * @param specialization the property name specialization (e.g., session
+ * name)
+ */
+ public SpecProperties(String prefix, String specialization) {
+ this.prefix = withTrailingDot(prefix);
+ this.specPrefix = withTrailingDot(this.prefix + specialization);
+ }
+
+ /**
+ *
+ * @param prefix the property name prefix that appears before any
+ * specialization
+ * @param specialization the property name specialization (e.g., session
+ * name)
+ * @param props the default properties
+ */
+ public SpecProperties(String prefix, String specialization, Properties props) {
+ super(props);
+
+ this.prefix = withTrailingDot(prefix);
+ this.specPrefix = withTrailingDot(this.prefix + specialization);
+ }
+
+ /**
+ * Adds a trailing "." to a String, if it doesn't already have one.
+ *
+ * @param text text to which the "." should be added
+ * @return the text, with a trailing "."
+ */
+ private static String withTrailingDot(String text) {
+ return text.endsWith(".") ? text : text + ".";
+ }
+
+ /**
+ * Gets the property whose value has the given key, looking first for the
+ * specialized property name, and then for the generalized property name.
+ *
+ * @param key property name, without the specialization
+ * @return the value from the property set, or {@code null} if the property
+ * set does not contain the value
+ */
+ public String getProperty(String key) {
+ if (!key.startsWith(prefix)) {
+ return super.getProperty(key);
+ }
+
+ String suffix = key.substring(prefix.length());
+
+ String val = super.getProperty(specPrefix + suffix);
+ if (val != null) {
+ return val;
+ }
+
+ return super.getProperty(key);
+ }
+
+ protected String getPrefix() {
+ return prefix;
+ }
+
+ protected String getSpecPrefix() {
+ return specPrefix;
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java
new file mode 100644
index 00000000..cb12a6ac
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ClassExtractors.java
@@ -0,0 +1,466 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.Properties;
+import java.util.concurrent.ConcurrentHashMap;
+import org.apache.commons.lang.StringUtils;
+import org.onap.policy.drools.utils.Pair;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Extractors for each object class. Properties define how the data is to be
+ * extracted for a given class, where the properties are similar to the
+ * following:
+ *
+ * <pre>
+ * <code>&lt;a.prefix>.&lt;class.name> = ${event.reqid}</code>
+ * </pre>
+ *
+ * If it doesn't find a property for the class, then it looks for a property for
+ * that class' super class or interfaces. Extractors are compiled and cached.
+ */
+public class ClassExtractors {
+
+ private static final Logger logger = LoggerFactory.getLogger(ClassExtractors.class);
+
+ /**
+ * Properties that specify how the data is to be extracted from a given
+ * class.
+ */
+ private final Properties properties;
+
+ /**
+ * Property prefix, including a trailing ".".
+ */
+ private final String prefix;
+
+ /**
+ * Type of item to be extracted.
+ */
+ private final String type;
+
+ /**
+ * Maps the class name to its extractor.
+ */
+ private final ConcurrentHashMap<String, Extractor> class2extractor = new ConcurrentHashMap<>();
+
+ /**
+ *
+ * @param props properties that specify how the data is to be extracted from
+ * a given class
+ * @param prefix property name prefix, prepended before the class name
+ * @param type type of item to be extracted
+ */
+ public ClassExtractors(Properties props, String prefix, String type) {
+ this.properties = props;
+ this.prefix = (prefix.endsWith(".") ? prefix : prefix + ".");
+ this.type = type;
+ }
+
+ /**
+ * Gets the number of extractors in the map.
+ *
+ * @return gets the number of extractors in the map
+ */
+ protected int size() {
+ return class2extractor.size();
+ }
+
+ /**
+ * Extracts the desired data item from an object.
+ *
+ * @param object object from which to extract the data item
+ * @return the extracted item, or {@code null} if it could not be extracted
+ */
+ public Object extract(Object object) {
+ if (object == null) {
+ return null;
+ }
+
+ Extractor ext = getExtractor(object);
+
+ return ext.extract(object);
+ }
+
+ /**
+ * Gets the extractor for the given type of object, creating one if it
+ * doesn't exist yet.
+ *
+ * @param object object whose extracted is desired
+ * @return an extractor for the object
+ */
+ private Extractor getExtractor(Object object) {
+ Class<?> clazz = object.getClass();
+ Extractor ext = class2extractor.get(clazz.getName());
+
+ if (ext == null) {
+ // allocate a new extractor, if another thread doesn't beat us to it
+ ext = class2extractor.computeIfAbsent(clazz.getName(), xxx -> buildExtractor(clazz));
+ }
+
+ return ext;
+ }
+
+ /**
+ * Builds an extractor for the class.
+ *
+ * @param clazz class for which the extractor should be built
+ *
+ * @return a new extractor
+ */
+ private Extractor buildExtractor(Class<?> clazz) {
+ String value = properties.getProperty(prefix + clazz.getName(), null);
+ if (value != null) {
+ // property has config info for this class - build the extractor
+ return buildExtractor(clazz, value);
+ }
+
+ /*
+ * Get the extractor, if any, for the super class or interfaces, but
+ * don't add one if it doesn't exist
+ */
+ Extractor ext = getClassExtractor(clazz, false);
+ if (ext != null) {
+ return ext;
+ }
+
+ /*
+ * No extractor defined for for this class or its super class - we
+ * cannot extract data items from objects of this type, so just
+ * allocated a null extractor.
+ */
+ logger.warn("missing property " + prefix + clazz.getName());
+ return new NullExtractor();
+ }
+
+ /**
+ * Builds an extractor for the class, based on the config value extracted
+ * from the corresponding property.
+ *
+ * @param clazz class for which the extractor should be built
+ * @param value config value (e.g., "${event.request.id}"
+ * @return a new extractor
+ */
+ private Extractor buildExtractor(Class<?> clazz, String value) {
+ if (!value.startsWith("${")) {
+ logger.warn("property value for " + prefix + clazz.getName() + " does not start with '${'");
+ return new NullExtractor();
+ }
+
+ if (!value.endsWith("}")) {
+ logger.warn("property value for " + prefix + clazz.getName() + " does not end with '}'");
+ return new NullExtractor();
+ }
+
+ // get the part in the middle
+ String val = value.substring(2, value.length() - 1);
+ if (val.startsWith(".")) {
+ logger.warn("property value for " + prefix + clazz.getName() + " begins with '.'");
+ return new NullExtractor();
+ }
+
+ if (val.endsWith(".")) {
+ logger.warn("property value for " + prefix + clazz.getName() + " ends with '.'");
+ return new NullExtractor();
+ }
+
+ // everything's valid - create the extractor
+ try {
+ ComponetizedExtractor ext = new ComponetizedExtractor(clazz, val.split("[.]"));
+
+ /*
+ * If there's only one extractor, then just return it, otherwise
+ * return the whole extractor.
+ */
+ return (ext.extractors.length == 1 ? ext.extractors[0] : ext);
+
+ } catch (ExtractorException e) {
+ logger.warn("cannot build extractor for " + clazz.getName());
+ return new NullExtractor();
+ }
+ }
+
+ /**
+ * Gets the extractor for a class, examining all super classes and
+ * interfaces.
+ *
+ * @param clazz class whose extractor is desired
+ * @param addOk {@code true} if the extractor may be added, provided the
+ * property is defined, {@code false} otherwise
+ * @return the extractor to be used for the class, or {@code null} if no
+ * extractor has been defined yet
+ */
+ private Extractor getClassExtractor(Class<?> clazz, boolean addOk) {
+ if (clazz == null) {
+ return null;
+ }
+
+ Extractor ext = null;
+
+ if (addOk) {
+ String val = properties.getProperty(prefix + clazz.getName(), null);
+
+ if (val != null) {
+ /*
+ * A property is defined for this class, so create the extractor
+ * for it.
+ */
+ return class2extractor.computeIfAbsent(clazz.getName(), xxx -> buildExtractor(clazz));
+ }
+ }
+
+ // see if the superclass has an extractor
+ if ((ext = getClassExtractor(clazz.getSuperclass(), true)) != null) {
+ return ext;
+ }
+
+ // check the interfaces, too
+ for (Class<?> clz : clazz.getInterfaces()) {
+ if ((ext = getClassExtractor(clz, true)) != null) {
+ break;
+ }
+ }
+
+ return ext;
+ }
+
+ /**
+ * Extractor that always returns {@code null}. Used when no extractor could
+ * be built for a given object type.
+ */
+ private class NullExtractor implements Extractor {
+
+ @Override
+ public Object extract(Object object) {
+ logger.warn("cannot extract " + type + " from " + object.getClass());
+ return null;
+ }
+ }
+
+ /**
+ * Component-ized extractor. Extracts an object that is referenced
+ * hierarchically, where each name identifies a particular component within
+ * the hierarchy. Supports retrieval from {@link Map} objects, as well as
+ * via getXxx() methods, or by direct field retrieval.
+ * <p>
+ * Note: this will <i>not</i> work if POJOs are contained within a Map.
+ */
+ private class ComponetizedExtractor implements Extractor {
+
+ /**
+ * Extractor for each component.
+ */
+ private final Extractor[] extractors;
+
+ /**
+ *
+ * @param clazz the class associated with the object at the root of the
+ * hierarchy
+ * @param names name associated with each component
+ * @throws ExtractorException
+ */
+ public ComponetizedExtractor(Class<?> clazz, String[] names) throws ExtractorException {
+ this.extractors = new Extractor[names.length];
+
+ Class<?> clz = clazz;
+
+ for (int x = 0; x < names.length; ++x) {
+ String comp = names[x];
+
+ Pair<Extractor, Class<?>> pair = buildExtractor(clz, comp);
+
+ extractors[x] = pair.first();
+ clz = pair.second();
+ }
+ }
+
+ /**
+ * Builds an extractor for the given component of an object.
+ *
+ * @param clazz type of object from which the component will be
+ * extracted
+ * @param comp name of the component to extract
+ * @return a pair containing the extractor and the extracted object's
+ * type
+ * @throws ExtractorException
+ */
+ private Pair<Extractor, Class<?>> buildExtractor(Class<?> clazz, String comp) throws ExtractorException {
+ Pair<Extractor, Class<?>> pair = null;
+
+ if (pair == null) {
+ pair = getMethodExtractor(clazz, comp);
+ }
+
+ if (pair == null) {
+ pair = getFieldExtractor(clazz, comp);
+ }
+
+ if (pair == null) {
+ pair = getMapExtractor(clazz, comp);
+ }
+
+
+ // didn't find an extractor
+ if (pair == null) {
+ throw new ExtractorException("class " + clazz + " contains no element " + comp);
+ }
+
+ return pair;
+ }
+
+ @Override
+ public Object extract(Object object) {
+ Object obj = object;
+
+ for (Extractor ext : extractors) {
+ if (obj == null) {
+ break;
+ }
+
+ obj = ext.extract(obj);
+ }
+
+ return obj;
+ }
+
+ /**
+ * Gets an extractor that invokes a getXxx() method to retrieve the
+ * object.
+ *
+ * @param clazz container's class
+ * @param name name of the property to be retrieved
+ * @return a new extractor, or {@code null} if the class does not
+ * contain the corresponding getXxx() method
+ * @throws ExtractorException if the getXxx() method is inaccessible
+ */
+ private Pair<Extractor, Class<?>> getMethodExtractor(Class<?> clazz, String name) throws ExtractorException {
+ Method meth;
+
+ String nm = "get" + StringUtils.capitalize(name);
+
+ try {
+ meth = clazz.getMethod(nm);
+
+ Class<?> retType = meth.getReturnType();
+ if (retType == void.class) {
+ // it's a void method, thus it won't return an object
+ return null;
+ }
+
+ return new Pair<>(new MethodExtractor(meth), retType);
+
+ } catch (NoSuchMethodException expected) {
+ // no getXxx() method, maybe there's a field by this name
+ return null;
+
+ } catch (SecurityException e) {
+ throw new ExtractorException("inaccessible method " + clazz + "." + nm, e);
+ }
+ }
+
+ /**
+ * Gets an extractor for a field within the object.
+ *
+ * @param clazz container's class
+ * @param name name of the field whose value is to be extracted
+ * @return a new extractor, or {@code null} if the class does not
+ * contain the given field
+ * @throws ExtractorException if the field is inaccessible
+ */
+ private Pair<Extractor, Class<?>> getFieldExtractor(Class<?> clazz, String name) throws ExtractorException {
+
+ Field field = getClassField(clazz, name);
+ if (field == null) {
+ return null;
+ }
+
+ return new Pair<>(new FieldExtractor(field), field.getType());
+ }
+
+ /**
+ * Gets an extractor for an item within a Map object.
+ *
+ * @param clazz container's class
+ * @param key item key within the map
+ * @return a new extractor, or {@code null} if the class is not a Map
+ * subclass
+ * @throws ExtractorException
+ */
+ private Pair<Extractor, Class<?>> getMapExtractor(Class<?> clazz, String key) throws ExtractorException {
+
+ if (!Map.class.isAssignableFrom(clazz)) {
+ return null;
+ }
+
+ /*
+ * Don't know the value's actual type, so we'll assume it's a Map
+ * for now. Things should still work OK, as this is only used to
+ * direct the constructor on what type of extractor to create next.
+ * If the object turns out not to be a map, then the MapExtractor
+ * for the next component will just return null.
+ */
+ return new Pair<>(new MapExtractor(key), Map.class);
+ }
+
+ /**
+ * Gets field within a class, examining all super classes and
+ * interfaces.
+ *
+ * @param clazz class whose field is desired
+ * @param name name of the desired field
+ * @return the field within the class, or {@code null} if the field does
+ * not exist
+ * @throws ExtractorException if the field is inaccessible
+ */
+ private Field getClassField(Class<?> clazz, String name) throws ExtractorException {
+ if (clazz == null) {
+ return null;
+ }
+
+ try {
+ return clazz.getDeclaredField(name);
+
+ } catch (NoSuchFieldException expected) {
+ // no field by this name - try super class & interfaces
+
+ } catch (SecurityException e) {
+ throw new ExtractorException("inaccessible field " + clazz + "." + name, e);
+ }
+
+
+ Field field;
+
+ // see if the superclass has an extractor
+ if ((field = getClassField(clazz.getSuperclass(), name)) != null) {
+ return field;
+ }
+
+ // not necessary to check the interfaces
+
+ return field;
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/Extractor.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/Extractor.java
new file mode 100644
index 00000000..9ed32ae4
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/Extractor.java
@@ -0,0 +1,35 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+/**
+ * Used to extract an object contained within another object.
+ */
+public interface Extractor {
+
+ /**
+ * Extracts an object contained within another object.
+ *
+ * @param object object from which to extract the contained object
+ * @return the extracted value, or {@code null} if it cannot be extracted
+ */
+ public Object extract(Object object);
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ExtractorException.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ExtractorException.java
new file mode 100644
index 00000000..a864672b
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/ExtractorException.java
@@ -0,0 +1,49 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+/**
+ * Exception generated by extractors.
+ */
+public class ExtractorException extends Exception {
+ private static final long serialVersionUID = 1L;
+
+ public ExtractorException() {
+ super();
+ }
+
+ public ExtractorException(String message) {
+ super(message);
+ }
+
+ public ExtractorException(Throwable cause) {
+ super(cause);
+ }
+
+ public ExtractorException(String message, Throwable cause) {
+ super(message, cause);
+ }
+
+ public ExtractorException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+ super(message, cause, enableSuppression, writableStackTrace);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java
new file mode 100644
index 00000000..132b8ed0
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java
@@ -0,0 +1,59 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+import java.lang.reflect.Field;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Used to extract an object stored in one of the container's fields.
+ */
+public class FieldExtractor implements Extractor {
+
+ private static final Logger logger = LoggerFactory.getLogger(FieldExtractor.class);
+
+ /**
+ * Field containing the object.
+ */
+ private final Field field;
+
+ /**
+ *
+ * @param field field containing the object
+ */
+ public FieldExtractor(Field field) {
+ this.field = field;
+
+ field.setAccessible(true);
+ }
+
+ @Override
+ public Object extract(Object object) {
+ try {
+ return field.get(object);
+
+ } catch (IllegalAccessException | IllegalArgumentException e) {
+ logger.warn("cannot get {} from {}", field.getName(), object.getClass(), e);
+ return null;
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MapExtractor.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MapExtractor.java
new file mode 100644
index 00000000..aff9d860
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MapExtractor.java
@@ -0,0 +1,60 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Used to extract an object stored in a map.
+ */
+public class MapExtractor implements Extractor {
+
+ private static final Logger logger = LoggerFactory.getLogger(MapExtractor.class);
+
+ /**
+ * Key to the item to extract from the map.
+ */
+ private final String key;
+
+ /**
+ *
+ * @param key key to the item to extract from the map
+ */
+ public MapExtractor(String key) {
+ this.key = key;
+ }
+
+ @Override
+ public Object extract(Object object) {
+
+ if (object instanceof Map) {
+ Map<?, ?> map = (Map<?, ?>) object;
+
+ return map.get(key);
+
+ } else {
+ logger.warn("expecting a map, instead of " + object.getClass());
+ return null;
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MethodExtractor.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MethodExtractor.java
new file mode 100644
index 00000000..20c4a1a7
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/MethodExtractor.java
@@ -0,0 +1,58 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.extractor;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Used to extract an object by invoking a method on the container.
+ */
+public class MethodExtractor implements Extractor {
+
+ private static final Logger logger = LoggerFactory.getLogger(MethodExtractor.class);
+
+ /**
+ * Method to invoke to extract the contained object.
+ */
+ private final Method method;
+
+ /**
+ *
+ * @param method method to invoke to extract the contained object
+ */
+ public MethodExtractor(Method method) {
+ this.method = method;
+ }
+
+ @Override
+ public Object extract(Object object) {
+ try {
+ return method.invoke(object);
+
+ } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+ logger.warn("cannot invoke {} on {}", method.getName(), object.getClass(), e);
+ return null;
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/BucketAssignments.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/BucketAssignments.java
new file mode 100644
index 00000000..8fd86c1e
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/BucketAssignments.java
@@ -0,0 +1,215 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import org.onap.policy.drools.pooling.PoolingFeatureException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * Bucket assignments, which is simply an array of host names.
+ */
+public class BucketAssignments {
+
+ @JsonIgnore
+ private static final Logger logger = LoggerFactory.getLogger(BucketAssignments.class);
+
+ /**
+ * Number of buckets.
+ */
+ public static final int MAX_BUCKETS = 1024;
+
+ /**
+ * Identifies the host serving a particular bucket.
+ */
+ private String[] hostArray = null;
+
+ /**
+ *
+ */
+ public BucketAssignments() {
+ super();
+ }
+
+ /**
+ *
+ * @param hostArray maps a bucket number (i.e., array index) to a host. All
+ * values must be non-null
+ */
+ public BucketAssignments(String[] hostArray) {
+ this.hostArray = hostArray;
+ }
+
+ public String[] getHostArray() {
+ return hostArray;
+ }
+
+ public void setHostArray(String[] hostArray) {
+ this.hostArray = hostArray;
+ }
+
+ /**
+ * Gets the leader, which is the host with the minimum UUID.
+ *
+ * @return the assignment leader
+ */
+ @JsonIgnore
+ public String getLeader() {
+ if (hostArray == null) {
+ return null;
+ }
+
+ String leader = null;
+
+ for (String host : hostArray) {
+ if (host != null && (leader == null || host.compareTo(leader) < 0)) {
+ leader = host;
+ }
+ }
+
+ return leader;
+
+ }
+
+ /**
+ * Determines if a host has an assignment.
+ *
+ * @param host host to be checked
+ * @return {@code true} if the host has an assignment, {@code false}
+ * otherwise
+ */
+ @JsonIgnore
+ public boolean hasAssignment(String host) {
+ if (hostArray == null) {
+ return false;
+ }
+
+ for (String host2 : hostArray) {
+ if (host.equals(host2)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Gets all of the hosts that have an assignment.
+ *
+ * @return all of the hosts that have an assignment
+ */
+ @JsonIgnore
+ public Set<String> getAllHosts() {
+ Set<String> set = new HashSet<>();
+ if (hostArray == null) {
+ return set;
+ }
+
+ for (String host : hostArray) {
+ if (host != null) {
+ set.add(host);
+ }
+ }
+
+ return set;
+ }
+
+ /**
+ * Gets the host assigned to a given bucket.
+ *
+ * @param bucket bucket number
+ * @return the assigned host, or {@code null} if the bucket has no assigned
+ * host
+ */
+ @JsonIgnore
+ public String getAssignedHost(int bucket) {
+ if (hostArray == null) {
+ logger.error("no buckets have been assigned");
+ return null;
+ }
+
+ if (bucket < 0 || bucket >= hostArray.length) {
+ logger.error("invalid bucket number {} maximum {}", bucket, hostArray.length);
+ return null;
+ }
+
+ return hostArray[bucket];
+ }
+
+ /**
+ * Gets the number of buckets.
+ *
+ * @return the number of buckets
+ */
+ @JsonIgnore
+ public int size() {
+ return (hostArray != null ? hostArray.length : 0);
+ }
+
+ /**
+ * Checks the validity of the assignments, verifying that all buckets have
+ * been assigned to a host.
+ *
+ * @throws PoolingFeatureException if the assignments are invalid
+ */
+ @JsonIgnore
+ public void checkValidity() throws PoolingFeatureException {
+ if (hostArray == null || hostArray.length == 0) {
+ throw new PoolingFeatureException("missing hosts in message bucket assignments");
+ }
+
+ if (hostArray.length > MAX_BUCKETS) {
+ throw new PoolingFeatureException("too many hosts in message bucket assignments");
+ }
+
+ for (int x = 0; x < hostArray.length; ++x) {
+ if (hostArray[x] == null) {
+ throw new PoolingFeatureException("bucket " + x + " has no assignment");
+ }
+ }
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+ result = prime * result + Arrays.hashCode(hostArray);
+ return result;
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj)
+ return true;
+ if (obj == null)
+ return false;
+ if (getClass() != obj.getClass())
+ return false;
+ BucketAssignments other = (BucketAssignments) obj;
+ if (!Arrays.equals(hostArray, other.hostArray))
+ return false;
+ return true;
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Forward.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Forward.java
new file mode 100644
index 00000000..b59cfbb2
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Forward.java
@@ -0,0 +1,180 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+import org.onap.policy.drools.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.drools.pooling.PoolingFeatureException;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * Message to forward an event to another host.
+ */
+public class Forward extends Message {
+
+ /**
+ * Number of hops (i.e., number of times it's been forwarded) so far.
+ */
+ private int numHops;
+
+ /**
+ * Time, in milliseconds, at which the message was created.
+ */
+ private long createTimeMs;
+
+ /**
+ * Protocol of the receiving topic.
+ */
+ private CommInfrastructure protocol;
+
+ /**
+ * Topic on which the event was received.
+ */
+ private String topic;
+
+ /**
+ * The event pay load that was received on the topic.
+ */
+ private String payload;
+
+ /**
+ * The request id that was extracted from the event.
+ */
+ private String requestId;
+
+ /**
+ *
+ */
+ public Forward() {
+ super();
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ * @param protocol
+ * @param topic
+ * @param payload the actual event data received on the topic
+ * @param requestId
+ */
+ public Forward(String source, CommInfrastructure protocol, String topic, String payload, String requestId) {
+ super(source);
+
+ this.numHops = 0;
+ this.createTimeMs = System.currentTimeMillis();
+ this.protocol = protocol;
+ this.topic = topic;
+ this.payload = payload;
+ this.requestId = requestId;
+ }
+
+ /**
+ * Increments {@link #numHops}.
+ */
+ public void bumpNumHops() {
+ ++numHops;
+ }
+
+ public int getNumHops() {
+ return numHops;
+ }
+
+ public void setNumHops(int numHops) {
+ this.numHops = numHops;
+ }
+
+ public long getCreateTimeMs() {
+ return createTimeMs;
+ }
+
+ public void setCreateTimeMs(long createTimeMs) {
+ this.createTimeMs = createTimeMs;
+ }
+
+ public CommInfrastructure getProtocol() {
+ return protocol;
+ }
+
+ public void setProtocol(CommInfrastructure protocol) {
+ this.protocol = protocol;
+ }
+
+ public String getTopic() {
+ return topic;
+ }
+
+ public void setTopic(String topic) {
+ this.topic = topic;
+ }
+
+ public String getPayload() {
+ return payload;
+ }
+
+ public void setPayload(String payload) {
+ this.payload = payload;
+ }
+
+ public String getRequestId() {
+ return requestId;
+ }
+
+ public void setRequestId(String requestId) {
+ this.requestId = requestId;
+ }
+
+ @JsonIgnore
+ public boolean isExpired(long minCreateTimeMs) {
+ return (createTimeMs < minCreateTimeMs);
+
+ }
+
+ @JsonIgnore
+ public void checkValidity() throws PoolingFeatureException {
+
+ super.checkValidity();
+
+ if (protocol == null) {
+ throw new PoolingFeatureException("missing message protocol");
+ }
+
+ if (topic == null || topic.isEmpty()) {
+ throw new PoolingFeatureException("missing message topic");
+ }
+
+ /*
+ * Note: an empty pay load is OK, as an empty message could have been
+ * received on the topic.
+ */
+
+ if (payload == null) {
+ throw new PoolingFeatureException("missing message payload");
+ }
+
+ if (requestId == null || requestId.isEmpty()) {
+ throw new PoolingFeatureException("missing message requestId");
+ }
+
+ if (numHops < 0) {
+ throw new PoolingFeatureException("invalid message hop count");
+ }
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Heartbeat.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Heartbeat.java
new file mode 100644
index 00000000..2a63a5be
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Heartbeat.java
@@ -0,0 +1,60 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+/**
+ * Heart beat message sent to self, or to the succeeding host.
+ */
+public class Heartbeat extends Message {
+
+ /**
+ * Time, in milliseconds, when this was created.
+ */
+ private long timestampMs;
+
+ /**
+ *
+ */
+ public Heartbeat() {
+ super();
+
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ * @param timestampMs time, in milliseconds, associated with the message
+ */
+ public Heartbeat(String source, long timestampMs) {
+ super(source);
+
+ this.timestampMs = timestampMs;
+ }
+
+ public long getTimestampMs() {
+ return timestampMs;
+ }
+
+ public void setTimestampMs(long timestampMs) {
+ this.timestampMs = timestampMs;
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Identification.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Identification.java
new file mode 100644
index 00000000..5de6b8f9
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Identification.java
@@ -0,0 +1,45 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+/**
+ * Identifies the source host and the bucket assignments which it knows about.
+ */
+public class Identification extends MessageWithAssignments {
+
+ /**
+ *
+ */
+ public Identification() {
+ super();
+
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ * @param assignments
+ */
+ public Identification(String source, BucketAssignments assignments) {
+ super(source, assignments);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Leader.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Leader.java
new file mode 100644
index 00000000..0fc48c3c
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Leader.java
@@ -0,0 +1,75 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+import org.onap.policy.drools.pooling.PoolingFeatureException;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * Indicates that the "source" of this message is now the "lead" host.
+ */
+public class Leader extends MessageWithAssignments {
+
+ /**
+ *
+ */
+ public Leader() {
+ super();
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ * @param assignments
+ */
+ public Leader(String source, BucketAssignments assignments) {
+ super(source, assignments);
+ }
+
+ /**
+ * Also verifies that buckets have been assigned and that the source is
+ * indeed the leader.
+ */
+ @Override
+ @JsonIgnore
+ public void checkValidity() throws PoolingFeatureException {
+
+ super.checkValidity();
+
+ BucketAssignments assignments = getAssignments();
+ if (assignments == null) {
+ throw new PoolingFeatureException("missing message bucket assignments");
+ }
+
+ String leader = getSource();
+
+ if(!assignments.hasAssignment(leader)) {
+ throw new PoolingFeatureException("leader " + leader + " has no bucket assignments");
+ }
+
+ for (String host : assignments.getHostArray()) {
+ if (host.compareTo(leader) < 0) {
+ throw new PoolingFeatureException("invalid leader " + leader + ", should be " + host);
+ }
+ }
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Message.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Message.java
new file mode 100644
index 00000000..e8a4671d
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Message.java
@@ -0,0 +1,103 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+import org.onap.policy.drools.pooling.PoolingFeatureException;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
+/**
+ * Messages sent on the internal topic.
+ */
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
+@JsonSubTypes({@Type(value = Forward.class, name = "forward"), @Type(value = Heartbeat.class, name = "heartbeat"),
+ @Type(value = Identification.class, name = "identification"),
+ @Type(value = Leader.class, name = "leader"), @Type(value = Offline.class, name = "offline"),
+ @Type(value = Query.class, name = "query")})
+public class Message {
+
+ /**
+ * Name of the administrative channel.
+ */
+ public static final String ADMIN = "_admin";
+
+ /**
+ * Host that originated the message.
+ */
+ private String source;
+
+ /**
+ * Channel on which the message is routed, which is either the target host
+ * or {@link #ADMIN}.
+ */
+ private String channel;
+
+ /**
+ *
+ */
+ public Message() {
+ super();
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ */
+ public Message(String source) {
+ this.source = source;
+ }
+
+ public String getSource() {
+ return source;
+ }
+
+ public void setSource(String source) {
+ this.source = source;
+ }
+
+ public String getChannel() {
+ return channel;
+ }
+
+ public void setChannel(String channel) {
+ this.channel = channel;
+ }
+
+ /**
+ * Checks the validity of the message, including verifying that required
+ * fields are not missing.
+ *
+ * @throws PoolingFeatureException if the message is invalid
+ */
+ @JsonIgnore
+ public void checkValidity() throws PoolingFeatureException {
+ if (source == null || source.isEmpty()) {
+ throw new PoolingFeatureException("missing message source");
+ }
+
+ if (channel == null || channel.isEmpty()) {
+ throw new PoolingFeatureException("missing message channel");
+ }
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/MessageWithAssignments.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/MessageWithAssignments.java
new file mode 100644
index 00000000..9fded815
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/MessageWithAssignments.java
@@ -0,0 +1,77 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+import org.onap.policy.drools.pooling.PoolingFeatureException;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * A Message that includes bucket assignments.
+ */
+public class MessageWithAssignments extends Message {
+
+ /**
+ * Bucket assignments, as known by the source host.
+ */
+ private BucketAssignments assignments;
+
+ /**
+ *
+ */
+ public MessageWithAssignments() {
+ super();
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ * @param assignments
+ */
+ public MessageWithAssignments(String source, BucketAssignments assignments) {
+ super(source);
+
+ this.assignments = assignments;
+
+ }
+
+ public BucketAssignments getAssignments() {
+ return assignments;
+ }
+
+ public void setAssignments(BucketAssignments assignments) {
+ this.assignments = assignments;
+ }
+
+ /**
+ * If there are any assignments, it verifies there validity.
+ */
+ @Override
+ @JsonIgnore
+ public void checkValidity() throws PoolingFeatureException {
+
+ super.checkValidity();
+
+ if (assignments != null) {
+ assignments.checkValidity();
+ }
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Offline.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Offline.java
new file mode 100644
index 00000000..297671ac
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Offline.java
@@ -0,0 +1,45 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+/**
+ * Indicates that the source host is going offline and will be unable to process
+ * any further requests.
+ */
+public class Offline extends Message {
+
+ /**
+ *
+ */
+ public Offline() {
+ super();
+
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ */
+ public Offline(String source) {
+ super(source);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Query.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Query.java
new file mode 100644
index 00000000..c995a288
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/message/Query.java
@@ -0,0 +1,44 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.message;
+
+/**
+ * Query the other hosts for their identification.
+ */
+public class Query extends Message {
+
+ /**
+ *
+ */
+ public Query() {
+ super();
+
+ }
+
+ /**
+ *
+ * @param source host on which the message originated
+ */
+ public Query(String source) {
+ super(source);
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ActiveState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ActiveState.java
new file mode 100644
index 00000000..5f503a3b
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ActiveState.java
@@ -0,0 +1,255 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import java.util.Arrays;
+import java.util.TreeSet;
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.message.Heartbeat;
+import org.onap.policy.drools.pooling.message.Offline;
+import org.onap.policy.drools.pooling.message.Query;
+
+/**
+ * The active state. In this state, this host has one more more bucket
+ * assignments and processes any events associated with one of its buckets.
+ * Other events are forwarded to appropriate target hosts.
+ */
+public class ActiveState extends ProcessingState {
+
+ /**
+ * Set of hosts that have been assigned a bucket.
+ */
+ private final TreeSet<String> assigned = new TreeSet<>();
+
+ /**
+ * Host that comes after this host, or {@code null} if it has no successor.
+ */
+ private String succHost = null;
+
+ /**
+ * Host that comes before this host, or "" if it has no predecessor.
+ */
+ private String predHost = "";
+
+ /**
+ * {@code True} if we saw this host's heart beat since the last check,
+ * {@code false} otherwise.
+ */
+ private boolean myHeartbeatSeen = false;
+
+ /**
+ * {@code True} if we saw the predecessor's heart beat since the last check,
+ * {@code false} otherwise.
+ */
+ private boolean predHeartbeatSeen = false;
+
+ /**
+ *
+ * @param mgr
+ */
+ public ActiveState(PoolingManager mgr) {
+ super(mgr, mgr.getAssignments().getLeader());
+
+ assigned.addAll(Arrays.asList(mgr.getAssignments().getHostArray()));
+
+ detmNeighbors();
+ }
+
+ /**
+ * Determine this host's neighbors based on the order of the host UUIDs.
+ * Updates {@link #succHost} and {@link #predHost}.
+ */
+ private void detmNeighbors() {
+ if (assigned.size() < 2) {
+ /*
+ * this host is the only one with any assignments - it has no
+ * neighbors
+ */
+ succHost = null;
+ predHost = "";
+ return;
+ }
+
+ if ((succHost = assigned.higher(getHost())) == null) {
+ // wrapped around - successor is the first host in the set
+ succHost = assigned.first();
+ }
+
+ if ((predHost = assigned.lower(getHost())) == null) {
+ // wrapped around - predecessor is the last host in the set
+ predHost = assigned.last();
+ }
+ }
+
+ @Override
+ public void start() {
+ addTimers();
+ genHeartbeat();
+ }
+
+ /**
+ * Adds the timers.
+ */
+ private void addTimers() {
+
+ /*
+ * heart beat generator
+ */
+ long genMs = getProperties().getActiveHeartbeatMs();
+
+ scheduleWithFixedDelay(genMs, genMs, xxx -> {
+ genHeartbeat();
+ return null;
+ });
+
+ /*
+ * my heart beat checker
+ */
+ long interMs = getProperties().getInterHeartbeatMs();
+
+ scheduleWithFixedDelay(interMs, interMs, xxx -> {
+ if (myHeartbeatSeen) {
+ myHeartbeatSeen = false;
+ return null;
+ }
+
+ // missed my heart beat
+
+ return internalTopicFailed();
+ });
+
+ /*
+ * predecessor heart beat checker
+ */
+ if (!predHost.isEmpty()) {
+
+ scheduleWithFixedDelay(interMs, interMs, xxx -> {
+ if (predHeartbeatSeen) {
+ predHeartbeatSeen = false;
+ return null;
+ }
+
+ // missed the predecessor's heart beat
+ publish(makeQuery());
+
+ return goQuery();
+ });
+ }
+ }
+
+ /**
+ * Generates a heart beat for this host and its successor.
+ */
+ private void genHeartbeat() {
+ Heartbeat msg = makeHeartbeat(System.currentTimeMillis());
+ publish(getHost(), msg);
+
+ if (succHost != null) {
+ publish(succHost, msg);
+ }
+ }
+
+ @Override
+ public State process(Heartbeat msg) {
+ String src = msg.getSource();
+
+ if (src == null) {
+ return null;
+
+ } else if (src.equals(getHost())) {
+ myHeartbeatSeen = true;
+
+ } else if (src.equals(predHost)) {
+ predHeartbeatSeen = true;
+
+ }
+
+ return null;
+ }
+
+ @Override
+ public State process(Offline msg) {
+ String src = msg.getSource();
+
+ if (src == null) {
+ return null;
+
+ } else if (!assigned.contains(src)) {
+ /*
+ * the offline host wasn't assigned any buckets, so just ignore the
+ * message
+ */
+ return null;
+
+ } else if (isLeader() || (predHost.equals(src) && predHost.equals(assigned.first()))) {
+ /*
+ * Case 1: We are the leader.
+ *
+ * Case 2: Our predecessor was the leader and it has gone offline -
+ * we should become the leader.
+ *
+ * In either case, we are now the leader and we must re-balance the
+ * buckets since one of the hosts has gone offline.
+ */
+
+ assigned.remove(src);
+
+ return becomeLeader(assigned);
+
+ } else {
+ /*
+ * Otherwise, we don't care right now - we'll wait for the leader to
+ * tell us it's been removed.
+ */
+ return null;
+ }
+ }
+
+ /**
+ * Transitions to the query state.
+ */
+ @Override
+ public State process(Query msg) {
+ State next = super.process(msg);
+ if (next != null) {
+ return next;
+ }
+
+ return goQuery();
+ }
+
+ protected String getSuccHost() {
+ return succHost;
+ }
+
+ protected String getPredHost() {
+ return predHost;
+ }
+
+ protected boolean isMyHeartbeatSeen() {
+ return myHeartbeatSeen;
+ }
+
+ protected boolean isPredHeartbeatSeen() {
+ return predHeartbeatSeen;
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/FilterUtils.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/FilterUtils.java
new file mode 100644
index 00000000..a2da0ea2
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/FilterUtils.java
@@ -0,0 +1,96 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * Filter Utilities. These methods create <i>TreeMap</i> objects, because they
+ * should only contain a small number of items.
+ */
+public class FilterUtils {
+ // message element names
+ public static final String MSG_CHANNEL = "channel";
+ public static final String MSG_TIMESTAMP = "timestampMs";
+
+ // json element names
+ protected static final String JSON_CLASS = "class";
+ protected static final String JSON_FILTERS = "filters";
+ protected static final String JSON_FIELD = "field";
+ protected static final String JSON_VALUE = "value";
+
+ // values to be stuck into the "class" element
+ protected static final String CLASS_OR = "Or";
+ protected static final String CLASS_AND = "And";
+ protected static final String CLASS_EQUALS = "Equals";
+
+ /**
+ *
+ */
+ private FilterUtils() {
+ super();
+ }
+
+ /**
+ * Makes a filter that verifies that a field equals a value.
+ *
+ * @param field name of the field to check
+ * @param value desired value
+ * @return a map representing an "equals" filter
+ */
+ public static Map<String, Object> makeEquals(String field, String value) {
+ Map<String, Object> map = new TreeMap<>();
+ map.put(JSON_CLASS, CLASS_EQUALS);
+ map.put(JSON_FIELD, field);
+ map.put(JSON_VALUE, value);
+
+ return map;
+ }
+
+ /**
+ * Makes an "and" filter, where all of the items must be true.
+ *
+ * @param items items to be checked
+ * @return an "and" filter
+ */
+ public static Map<String, Object> makeAnd(@SuppressWarnings("unchecked") Map<String, Object>... items) {
+ Map<String, Object> map = new TreeMap<>();
+ map.put(JSON_CLASS, CLASS_AND);
+ map.put(JSON_FILTERS, items);
+
+ return map;
+ }
+
+ /**
+ * Makes an "or" filter, where at least one of the items must be true.
+ *
+ * @param items items to be checked
+ * @return an "or" filter
+ */
+ public static Map<String, Object> makeOr(@SuppressWarnings("unchecked") Map<String, Object>... items) {
+ Map<String, Object> map = new TreeMap<>();
+ map.put(JSON_CLASS, CLASS_OR);
+ map.put(JSON_FILTERS, items);
+
+ return map;
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/IdleState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/IdleState.java
new file mode 100644
index 00000000..27678360
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/IdleState.java
@@ -0,0 +1,85 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.message.Heartbeat;
+import org.onap.policy.drools.pooling.message.Identification;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Offline;
+import org.onap.policy.drools.pooling.message.Query;
+
+/**
+ * Idle state, used when offline.
+ */
+public class IdleState extends State {
+
+ public IdleState(PoolingManager mgr) {
+ super(mgr);
+ }
+
+ @Override
+ public void stop() {
+ // do nothing - don't even send of "offline" message
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Heartbeat msg) {
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Identification msg) {
+ return null;
+ }
+
+ /**
+ * Copies the assignments, but doesn't change states.
+ */
+ @Override
+ public State process(Leader msg) {
+ super.process(msg);
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Offline msg) {
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Query msg) {
+ return null;
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/InactiveState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/InactiveState.java
new file mode 100644
index 00000000..1c8e4dcc
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/InactiveState.java
@@ -0,0 +1,55 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import org.onap.policy.drools.pooling.PoolingManager;
+
+/**
+ * The inactive state. In this state, we just wait a bit and then try to
+ * re-activate. In the meantime, all messages are ignored.
+ */
+public class InactiveState extends State {
+
+ /**
+ *
+ * @param mgr
+ */
+ public InactiveState(PoolingManager mgr) {
+ super(mgr);
+ }
+
+ @Override
+ public void start() {
+
+ super.start();
+
+ schedule(getProperties().getReactivateMs(), xxx -> goStart());
+ }
+
+ /**
+ * Remains in this state.
+ */
+ @Override
+ protected State goInactive() {
+ return null;
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ProcessingState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ProcessingState.java
new file mode 100644
index 00000000..2f830c66
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/ProcessingState.java
@@ -0,0 +1,410 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.message.BucketAssignments;
+import org.onap.policy.drools.pooling.message.Identification;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Query;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Any state in which events are being processed locally and forwarded, as
+ * appropriate.
+ */
+public class ProcessingState extends State {
+
+ private static final Logger logger = LoggerFactory.getLogger(ProcessingState.class);
+
+ /**
+ * Current known leader, never {@code null}.
+ */
+ private String leader;
+
+ /**
+ *
+ * @param mgr
+ * @param leader current known leader, which need not be the same as the
+ * assignment leader. Never {@code null}
+ * @throws IllegalArgumentException if an argument is invalid
+ */
+ public ProcessingState(PoolingManager mgr, String leader) {
+ super(mgr);
+
+ if (leader == null) {
+ throw new IllegalArgumentException("null leader");
+ }
+
+ BucketAssignments assignments = mgr.getAssignments();
+
+ if (assignments != null) {
+ String[] arr = assignments.getHostArray();
+ if (arr != null && arr.length == 0) {
+ throw new IllegalArgumentException("zero-length bucket assignments");
+ }
+ }
+
+ this.leader = leader;
+ }
+
+ /**
+ * Generates an Identification message and returns {@code null}.
+ */
+ @Override
+ public State process(Query msg) {
+ publish(makeIdentification());
+ return goQuery();
+ }
+
+ /**
+ * Makes an Identification message.
+ *
+ * @return a new message
+ */
+ protected Identification makeIdentification() {
+ return new Identification(getHost(), getAssignments());
+ }
+
+ /**
+ * Sets the assignments.
+ *
+ * @param assignments new assignments, or {@code null}
+ */
+ protected final void setAssignments(BucketAssignments assignments) {
+ if (assignments != null) {
+ startDistributing(assignments);
+ }
+ }
+
+ public String getLeader() {
+ return leader;
+ }
+
+ /**
+ * Sets the leader.
+ *
+ * @param leader the new leader
+ * @throws IllegalArgumentException if an argument is invalid
+ */
+ protected void setLeader(String leader) {
+ if (leader == null) {
+ throw new IllegalArgumentException("null leader");
+ }
+
+ this.leader = leader;
+ }
+
+ /**
+ * Determines if this host is the leader, based on the current assignments.
+ *
+ * @return {@code true} if this host is the leader, {@code false} otherwise
+ */
+ public boolean isLeader() {
+ return getHost().equals(leader);
+ }
+
+ /**
+ * Becomes the leader. Publishes a Leader message and enters the
+ * {@link ActiveState}.
+ *
+ * @param alive hosts that are known to be alive
+ *
+ * @return the new state
+ */
+ protected State becomeLeader(SortedSet<String> alive) {
+ String leader = getHost();
+
+ if (!leader.equals(alive.first())) {
+ throw new IllegalArgumentException(leader + " cannot replace " + alive.first());
+ }
+
+ Leader msg = makeLeader(alive);
+ publish(msg);
+
+ setAssignments(msg.getAssignments());
+
+ return goActive();
+ }
+
+ /**
+ * Makes a leader message. Assumes "this" host is the leader, and thus
+ * appears as the first host in the set of hosts that are still alive.
+ *
+ * @param alive hosts that are known to be alive
+ *
+ * @return a new message
+ */
+ private Leader makeLeader(Set<String> alive) {
+ return new Leader(getHost(), makeAssignments(alive));
+ }
+
+ /**
+ * Makes a set of bucket assignments. Assumes "this" host is the leader.
+ *
+ * @param alive hosts that are known to be alive
+ *
+ * @return a new set of bucket assignments
+ */
+ private BucketAssignments makeAssignments(Set<String> alive) {
+
+ // make a working array from the CURRENT assignments
+ String[] bucket2host = makeBucketArray();
+
+ TreeSet<String> avail = new TreeSet<>(alive);
+
+ // if we have more hosts than buckets, then remove the extra hosts
+ removeExcessHosts(bucket2host.length, avail);
+
+ // create a host bucket for each available host
+ Map<String, HostBucket> host2hb = new HashMap<>();
+ avail.forEach(host -> host2hb.put(host, new HostBucket(host)));
+
+ // add bucket indices to the appropriate host bucket
+ addIndicesToHostBuckets(bucket2host, host2hb);
+
+ // convert the collection back to an array
+ fillArray(host2hb.values(), bucket2host);
+
+ // update bucket2host with new assignments
+ rebalanceBuckets(host2hb.values(), bucket2host);
+
+ return new BucketAssignments(bucket2host);
+ }
+
+ /**
+ * Makes a bucket array, copying the current assignments, if available.
+ *
+ * @return a new bucket array
+ */
+ private String[] makeBucketArray() {
+ BucketAssignments asgn = getAssignments();
+ if (asgn == null) {
+ return new String[BucketAssignments.MAX_BUCKETS];
+ }
+
+ String[] oldArray = asgn.getHostArray();
+ if (oldArray.length == 0) {
+ return new String[BucketAssignments.MAX_BUCKETS];
+ }
+
+ String[] newArray = new String[oldArray.length];
+ System.arraycopy(oldArray, 0, newArray, 0, oldArray.length);
+
+ return newArray;
+ }
+
+ /**
+ * Removes excess hosts from the set of available hosts. Assumes "this" host
+ * is the leader, and thus appears as the first host in the set.
+ *
+ * @param maxHosts maximum number of hosts to be retained
+ * @param avail available hosts
+ */
+ private void removeExcessHosts(int maxHosts, SortedSet<String> avail) {
+ while (avail.size() > maxHosts) {
+ /*
+ * Don't remove this host, as it's the leader. Since the leader is
+ * always at the front of the sorted set, we'll just pick off hosts
+ * from the back of the set.
+ */
+ String host = avail.last();
+ avail.remove(host);
+
+ logger.warn("not using extra host {} for topic {}", host, getTopic());
+ }
+ }
+
+ /**
+ * Adds bucket indices to {@link HostBucket} objects. Buckets that are
+ * unassigned or assigned to a host that does not appear within the map are
+ * re-assigned to a host that appears within the map.
+ *
+ * @param bucket2host bucket assignments
+ * @param host2data maps a host name to its {@link HostBucket}
+ */
+ private void addIndicesToHostBuckets(String[] bucket2host, Map<String, HostBucket> host2data) {
+ LinkedList<Integer> nullBuckets = new LinkedList<Integer>();
+
+ for (int x = 0; x < bucket2host.length; ++x) {
+ String host = bucket2host[x];
+ if (host == null) {
+ nullBuckets.add(x);
+
+ } else {
+ HostBucket hb = host2data.get(host);
+ if (hb == null) {
+ nullBuckets.add(x);
+
+ } else {
+ hb.add(x);
+ }
+ }
+ }
+
+ // assign the null buckets to other hosts
+ assignNullBuckets(nullBuckets, host2data.values());
+ }
+
+ /**
+ * Assigns null buckets (i.e., those having no assignment) to available
+ * hosts.
+ *
+ * @param buckets available hosts
+ * @param coll collection of current host-bucket assignments
+ */
+ private void assignNullBuckets(Queue<Integer> buckets, Collection<HostBucket> coll) {
+ // assign null buckets to the hosts with the fewest buckets
+ TreeSet<HostBucket> assignments = new TreeSet<>(coll);
+
+ for (Integer index : buckets) {
+ // add it to the host with the shortest bucket list
+ HostBucket newhb = assignments.pollFirst();
+ newhb.add(index);
+
+ // put the item back into the queue, with its new count
+ assignments.add(newhb);
+ }
+ }
+
+ /**
+ * Re-balances the buckets, taking from those that have a larger count and
+ * giving to those that have a smaller count. Populates an output array with
+ * the new assignments.
+ *
+ * @param coll current bucket assignment
+ * @param bucket2host array to be populated with the new assignments
+ */
+ private void rebalanceBuckets(Collection<HostBucket> coll, String[] bucket2host) {
+ if (coll.size() <= 1) {
+ // only one hosts - nothing to rebalance
+ return;
+ }
+
+ TreeSet<HostBucket> assignments = new TreeSet<>(coll);
+
+ for (;;) {
+ HostBucket smaller = assignments.pollFirst();
+ HostBucket larger = assignments.pollLast();
+
+ if (larger.size() - smaller.size() <= 1) {
+ // it's as balanced as it will get
+ break;
+ }
+
+ // move the bucket from the larger to the smaller
+ Integer b = larger.remove();
+ smaller.add(b);
+
+ bucket2host[b] = smaller.host;
+
+ // put the items back, with their new counts
+ assignments.add(larger);
+ assignments.add(smaller);
+ }
+
+ }
+
+ /**
+ * Fills the array with the host assignments.
+ *
+ * @param coll the host assignments
+ * @param bucket2host array to be filled
+ */
+ private void fillArray(Collection<HostBucket> coll, String[] bucket2host) {
+ for (HostBucket hb : coll) {
+ for (Integer index : hb.buckets) {
+ bucket2host[index] = hb.host;
+ }
+ }
+ }
+
+ /**
+ * Tracks buckets that have been assigned to a host.
+ */
+ public static class HostBucket implements Comparable<HostBucket> {
+ /**
+ * Host to which the buckets have been assigned.
+ */
+ private String host;
+
+ /**
+ * Buckets that have been assigned to this host.
+ */
+ private Queue<Integer> buckets = new LinkedList<>();
+
+ /**
+ *
+ * @param host
+ */
+ public HostBucket(String host) {
+ this.host = host;
+ }
+
+ /**
+ * Removes the next bucket from the list.
+ *
+ * @return the next bucket
+ */
+ public final Integer remove() {
+ return buckets.remove();
+ }
+
+ /**
+ * Adds a bucket to the list.
+ *
+ * @param index index of the bucket to add
+ */
+ public final void add(Integer index) {
+ buckets.add(index);
+ }
+
+ /**
+ *
+ * @return the number of buckets assigned to this host
+ */
+ public final int size() {
+ return buckets.size();
+ }
+
+ /**
+ * Compares host buckets, first by the number of buckets, and then by
+ * the host name.
+ */
+ @Override
+ public final int compareTo(HostBucket other) {
+ int d = buckets.size() - other.buckets.size();
+ if (d == 0) {
+ d = host.compareTo(other.host);
+ }
+ return d;
+ }
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/QueryState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/QueryState.java
new file mode 100644
index 00000000..57521960
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/QueryState.java
@@ -0,0 +1,209 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import java.util.TreeSet;
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.message.BucketAssignments;
+import org.onap.policy.drools.pooling.message.Identification;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Offline;
+
+// TODO add logging
+
+/**
+ * The Query state. In this state, the host waits for the other hosts to
+ * identify themselves. Eventually, a leader should come forth. If not, it will
+ * transition to the active or inactive state, depending on whether or not it
+ * has an assignment in the current bucket assignments. The other possibility is
+ * that it may <i>become</i> the leader, in which case it will also transition
+ * to the active state.
+ */
+public class QueryState extends ProcessingState {
+
+ /**
+ * Hosts that have sent an "Identification" message. Always includes this
+ * host.
+ */
+ private TreeSet<String> alive = new TreeSet<>();
+
+ /**
+ *
+ * @param mgr
+ */
+ public QueryState(PoolingManager mgr) {
+ // this host is the leader, until a better candidate identifies itself
+ super(mgr, mgr.getHost());
+
+ alive.add(getHost());
+ }
+
+ @Override
+ public void start() {
+
+ super.start();
+
+ // start identification timer
+ awaitIdentification();
+ }
+
+ /**
+ * Starts a timer to wait for all Identification messages to arrive.
+ */
+ private void awaitIdentification() {
+
+ /*
+ * Once we've waited long enough for all Identification messages to
+ * arrive, become the leader, assuming we should.
+ */
+
+ schedule(getProperties().getIdentificationMs(), xxx -> {
+
+ if (isLeader()) {
+ // "this" host is the new leader
+ return becomeLeader(alive);
+
+ } else if (hasAssignment()) {
+ /*
+ * this host is not the new leader, but it does have an
+ * assignment - return to the active state while we wait for the
+ * leader
+ */
+ return goActive();
+
+ } else {
+ // not the leader and no assignment yet
+ return goInactive();
+ }
+ });
+ }
+
+ /**
+ * Remains in this state.
+ */
+ @Override
+ public State goQuery() {
+ return null;
+ }
+
+ /**
+ * Determines if this host has an assignment in the CURRENT assignments.
+ *
+ * @return {@code true} if this host has an assignment, {@code false}
+ * otherwise
+ */
+ protected boolean hasAssignment() {
+ BucketAssignments asgn = getAssignments();
+ return (asgn != null && asgn.hasAssignment(getHost()));
+ }
+
+ @Override
+ public State process(Identification msg) {
+
+ recordInfo(msg.getSource(), msg.getAssignments());
+
+ return null;
+ }
+
+ /**
+ * If the message leader is better than the leader we have, then go active
+ * with it. Otherwise, simply treat it like an {@link Identification}
+ * message.
+ */
+ @Override
+ public State process(Leader msg) {
+ BucketAssignments asgn = msg.getAssignments();
+ if (asgn == null) {
+ return null;
+ }
+
+ // ignore Leader messages from ourself
+ String source = msg.getSource();
+ if (source == null || source.equals(getHost())) {
+ return null;
+ }
+
+ // the new leader must equal the source
+ if (!source.equals(asgn.getLeader())) {
+ return null;
+ }
+
+ // go active, if this has a better leader than the one we have
+ if (source.compareTo(getLeader()) < 0) {
+ return super.process(msg);
+ }
+
+ /*
+ * The message does not have an acceptable leader, but we'll still
+ * record its info.
+ */
+ recordInfo(msg.getSource(), msg.getAssignments());
+
+ return null;
+ }
+
+ /**
+ * Records info from a message, adding the source host name to
+ * {@link #alive}, and updating the bucket assignments.
+ *
+ * @param source the message's source host
+ * @param assignments assignments, or {@code null}
+ */
+ private void recordInfo(String source, BucketAssignments assignments) {
+ // add this message's source host to "alive"
+ if (source != null) {
+ alive.add(source);
+ setLeader(alive.first());
+ }
+
+ if (assignments == null || assignments.getLeader() == null) {
+ return;
+ }
+
+ // record assignments, if we don't have any yet
+ BucketAssignments current = getAssignments();
+ if (current == null) {
+ setAssignments(assignments);
+ return;
+ }
+
+ /*
+ * Record assignments, if the new assignments have a better (i.e.,
+ * lesser) leader.
+ */
+ String curldr = current.getLeader();
+ if (curldr == null || curldr.compareTo(assignments.getLeader()) > 0) {
+ setAssignments(assignments);
+ }
+ }
+
+ @Override
+ public State process(Offline msg) {
+ String host = msg.getSource();
+
+ if (host != null && !host.equals(getHost())) {
+ alive.remove(host);
+ setLeader(alive.first());
+ }
+
+ return null;
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StartState.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StartState.java
new file mode 100644
index 00000000..decbdfda
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StartState.java
@@ -0,0 +1,132 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import static org.onap.policy.drools.pooling.state.FilterUtils.MSG_CHANNEL;
+import static org.onap.policy.drools.pooling.state.FilterUtils.MSG_TIMESTAMP;
+import static org.onap.policy.drools.pooling.state.FilterUtils.makeAnd;
+import static org.onap.policy.drools.pooling.state.FilterUtils.makeEquals;
+import static org.onap.policy.drools.pooling.state.FilterUtils.makeOr;
+import java.util.Map;
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.message.Heartbeat;
+import org.onap.policy.drools.pooling.message.Identification;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Message;
+import org.onap.policy.drools.pooling.message.Offline;
+import org.onap.policy.drools.pooling.message.Query;
+
+/**
+ * The start state. Upon entry, a heart beat is generated and the event filter
+ * is changed to look for just that particular message. Once the message is
+ * seen, it goes into the {@link QueryState}.
+ */
+public class StartState extends State {
+
+ /**
+ * Time stamp inserted into the heart beat message.
+ */
+ private long hbTimestampMs = System.currentTimeMillis();
+
+ /**
+ *
+ * @param mgr
+ */
+ public StartState(PoolingManager mgr) {
+ super(mgr);
+ }
+
+ /**
+ *
+ * @return the time stamp inserted into the heart beat message
+ */
+ public long getHbTimestampMs() {
+ return hbTimestampMs;
+ }
+
+ @Override
+ public void start() {
+
+ super.start();
+
+ publish(getHost(), makeHeartbeat(hbTimestampMs));
+
+ schedule(getProperties().getStartHeartbeatMs(), xxx -> internalTopicFailed());
+ }
+
+ /**
+ * Transitions to the query state if the heart beat originated from this
+ * host and its time stamp matches.
+ */
+ @Override
+ public State process(Heartbeat msg) {
+ if (msg.getTimestampMs() == hbTimestampMs && getHost().equals(msg.getSource())) {
+ // saw our own heart beat - transition to query state
+ publish(makeQuery());
+ return goQuery();
+ }
+
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Identification msg) {
+ return null;
+ }
+
+ /**
+ * Processes the assignments, but remains in the current state.
+ */
+ @Override
+ public State process(Leader msg) {
+ super.process(msg);
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Offline msg) {
+ return null;
+ }
+
+ /**
+ * Discards the message.
+ */
+ @Override
+ public State process(Query msg) {
+ return null;
+ }
+
+ @SuppressWarnings("unchecked")
+ @Override
+ public Map<String, Object> getFilter() {
+ // ignore everything except our most recent heart beat message
+ return makeOr(makeEquals(MSG_CHANNEL, Message.ADMIN), makeAnd(makeEquals(MSG_CHANNEL, getHost()),
+ makeEquals(MSG_TIMESTAMP, String.valueOf(hbTimestampMs))));
+
+ }
+
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/State.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/State.java
new file mode 100644
index 00000000..1e3a907e
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/State.java
@@ -0,0 +1,370 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+import static org.onap.policy.drools.pooling.state.FilterUtils.MSG_CHANNEL;
+import static org.onap.policy.drools.pooling.state.FilterUtils.makeEquals;
+import static org.onap.policy.drools.pooling.state.FilterUtils.makeOr;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ScheduledFuture;
+import org.onap.policy.drools.pooling.PoolingManager;
+import org.onap.policy.drools.pooling.PoolingProperties;
+import org.onap.policy.drools.pooling.message.BucketAssignments;
+import org.onap.policy.drools.pooling.message.Forward;
+import org.onap.policy.drools.pooling.message.Heartbeat;
+import org.onap.policy.drools.pooling.message.Identification;
+import org.onap.policy.drools.pooling.message.Leader;
+import org.onap.policy.drools.pooling.message.Message;
+import org.onap.policy.drools.pooling.message.Offline;
+import org.onap.policy.drools.pooling.message.Query;
+
+/**
+ * A state in the finite state machine.
+ * <p>
+ * A state may have several timers associated with it, which must be cancelled
+ * whenever the state is changed. Assumes that timers are not continuously added
+ * to the same state.
+ */
+public abstract class State {
+
+ /**
+ * Host pool manager.
+ */
+ private final PoolingManager mgr;
+
+ /**
+ * Timers added by this state.
+ */
+ private final List<ScheduledFuture<?>> timers = new LinkedList<>();
+
+ /**
+ *
+ * @param mgr
+ */
+ public State(PoolingManager mgr) {
+ this.mgr = mgr;
+ }
+
+ /**
+ * Gets the server-side filter to use when polling the DMaaP internal topic.
+ * The default method returns a filter that accepts messages on the admin
+ * channel and on the host's own channel.
+ *
+ * @return the server-side filter to use.
+ */
+ @SuppressWarnings("unchecked")
+ public Map<String, Object> getFilter() {
+ return makeOr(makeEquals(MSG_CHANNEL, Message.ADMIN), makeEquals(MSG_CHANNEL, getHost()));
+ }
+
+ /**
+ * Cancels the timers added by this state.
+ */
+ public void cancelTimers() {
+ for (ScheduledFuture<?> fut : timers) {
+ fut.cancel(false);
+ }
+ }
+
+ /**
+ * Starts the state.
+ */
+ public void start() {
+
+ }
+
+ /**
+ * Indicates that the finite state machine is stopping. Sends an "offline"
+ * message to the other hosts.
+ */
+ public void stop() {
+ publish(makeOffline());
+ }
+
+ /**
+ * Transitions to the "start" state.
+ *
+ * @return the new state
+ */
+ public State goStart() {
+ return mgr.goStart();
+ }
+
+ /**
+ * Transitions to the "query" state.
+ *
+ * @return the new state
+ */
+ public State goQuery() {
+ return mgr.goQuery();
+ }
+
+ /**
+ * Transitions to the "active" state.
+ *
+ * @return the new state
+ */
+ public State goActive() {
+ return mgr.goActive();
+ }
+
+ /**
+ * Transitions to the "inactive" state.
+ *
+ * @return the new state
+ */
+ protected State goInactive() {
+ return mgr.goInactive();
+ }
+
+ /**
+ * Processes a message. The default method passes it to the manager to
+ * handle and returns {@code null}.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Forward msg) {
+ mgr.handle(msg);
+ return null;
+ }
+
+ /**
+ * Processes a message. The default method just returns {@code null}.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Heartbeat msg) {
+ return null;
+ }
+
+ /**
+ * Processes a message. The default method just returns {@code null}.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Identification msg) {
+ return null;
+ }
+
+ /**
+ * Processes a message. If this host has a new assignment, then it
+ * transitions to the active state. Otherwise, it transitions to the
+ * inactive state.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Leader msg) {
+ BucketAssignments asgn = msg.getAssignments();
+ if (asgn == null) {
+ return null;
+ }
+
+ String source = msg.getSource();
+ if (source == null) {
+ return null;
+ }
+
+ // the new leader must equal the source
+ if (source.equals(asgn.getLeader())) {
+ startDistributing(asgn);
+
+ if (asgn.hasAssignment(getHost())) {
+ return goActive();
+
+ } else {
+ return goInactive();
+ }
+ }
+
+ return null;
+ }
+
+ /**
+ * Processes a message. The default method just returns {@code null}.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Offline msg) {
+ return null;
+ }
+
+ /**
+ * Processes a message. The default method just returns {@code null}.
+ *
+ * @param msg message to be processed
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State process(Query msg) {
+ return null;
+ }
+
+ /**
+ * Publishes a message.
+ *
+ * @param msg message to be published
+ */
+ protected void publish(Identification msg) {
+ mgr.publishAdmin(msg);
+ }
+
+ /**
+ * Publishes a message.
+ *
+ * @param msg message to be published
+ */
+ protected void publish(Leader msg) {
+ mgr.publishAdmin(msg);
+ }
+
+ /**
+ * Publishes a message.
+ *
+ * @param msg message to be published
+ */
+ protected void publish(Offline msg) {
+ mgr.publishAdmin(msg);
+ }
+
+ /**
+ * Publishes a message.
+ *
+ * @param msg message to be published
+ */
+ protected void publish(Query msg) {
+ mgr.publishAdmin(msg);
+ }
+
+ /**
+ * Publishes a message on the specified channel.
+ *
+ * @param channel
+ * @param msg message to be published
+ */
+ protected void publish(String channel, Forward msg) {
+ mgr.publish(channel, msg);
+ }
+
+ /**
+ * Publishes a message on the specified channel.
+ *
+ * @param channel
+ * @param msg message to be published
+ */
+ protected void publish(String channel, Heartbeat msg) {
+ mgr.publish(channel, msg);
+ }
+
+ /**
+ * Starts distributing messages using the specified bucket assignments.
+ *
+ * @param assignments
+ */
+ protected void startDistributing(BucketAssignments assignments) {
+ if (assignments != null) {
+ mgr.startDistributing(assignments);
+ }
+ }
+
+ /**
+ * Schedules a timer to fire after a delay.
+ *
+ * @param delayMs
+ * @param task
+ */
+ protected void schedule(long delayMs, StateTimerTask task) {
+ timers.add(mgr.schedule(delayMs, task));
+ }
+
+ /**
+ * Schedules a timer to fire repeatedly.
+ *
+ * @param initialDelayMs
+ * @param delayMs
+ * @param task
+ */
+ protected void scheduleWithFixedDelay(long initialDelayMs, long delayMs, StateTimerTask task) {
+ timers.add(mgr.scheduleWithFixedDelay(initialDelayMs, delayMs, task));
+ }
+
+ /**
+ * Indicates that the internal topic failed.
+ *
+ * @return a new {@link InactiveState}
+ */
+ protected State internalTopicFailed() {
+ publish(makeOffline());
+ mgr.internalTopicFailed();
+
+ return mgr.goInactive();
+ }
+
+ /**
+ * Makes a heart beat message.
+ *
+ * @param timestampMs time, in milliseconds, associated with the message
+ *
+ * @return a new message
+ */
+ protected Heartbeat makeHeartbeat(long timestampMs) {
+ return new Heartbeat(getHost(), timestampMs);
+ }
+
+ /**
+ * Makes an "offline" message.
+ *
+ * @return a new message
+ */
+ protected Offline makeOffline() {
+ return new Offline(getHost());
+ }
+
+ /**
+ * Makes a query message.
+ *
+ * @return a new message
+ */
+ protected Query makeQuery() {
+ return new Query(getHost());
+ }
+
+ public final BucketAssignments getAssignments() {
+ return mgr.getAssignments();
+ }
+
+ public final String getHost() {
+ return mgr.getHost();
+ }
+
+ public final String getTopic() {
+ return mgr.getTopic();
+ }
+
+ public final PoolingProperties getProperties() {
+ return mgr.getProperties();
+ }
+}
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StateTimerTask.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StateTimerTask.java
new file mode 100644
index 00000000..bd388b4e
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/state/StateTimerTask.java
@@ -0,0 +1,37 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.pooling.state;
+
+/**
+ * Task to be executed when a timer fires within a {@link State}.
+ */
+@FunctionalInterface
+public interface StateTimerTask {
+
+ /**
+ * Fires the timer.
+ *
+ * @param arg always {@code null}
+ * @return the new state, or {@code null} if the state is unchanged
+ */
+ public State fire(Void arg);
+
+}
diff --git a/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.core.PolicySessionFeatureAPI b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.core.PolicySessionFeatureAPI
new file mode 100644
index 00000000..cd59e469
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.core.PolicySessionFeatureAPI
@@ -0,0 +1 @@
+org.onap.policy.drools.pooling.PoolingFeature
diff --git a/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.DroolsControllerFeatureAPI b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.DroolsControllerFeatureAPI
new file mode 100644
index 00000000..cd59e469
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.DroolsControllerFeatureAPI
@@ -0,0 +1 @@
+org.onap.policy.drools.pooling.PoolingFeature
diff --git a/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.PolicyControllerFeatureAPI b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.PolicyControllerFeatureAPI
new file mode 100644
index 00000000..cd59e469
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/resources/META-INF/services/org.onap.policy.drools.features.PolicyControllerFeatureAPI
@@ -0,0 +1 @@
+org.onap.policy.drools.pooling.PoolingFeature