diff options
Diffstat (limited to 'feature-pooling-dmaap/src/main/java/org')
35 files changed, 5651 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><a.prefix>.<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); + +} |