Prometheues metrics for APEX engine stats

Issue-ID: POLICY-3846
Signed-off-by: Rashmi Pujar <rashmi.pujar1@bell.ca>
Change-Id: I385446683372548f3fed6d609a9e85633ec2916d

2 files changed, 74 insertions, 11 deletions

diff --git a/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineState.java b/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineState.java
index f77fe1910..63c8706d2 100644
--- a/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineState.java
+++ b/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineState.java
@@ -1,19 +1,20 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2022 Bell Canada. 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.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
@@ -34,13 +35,23 @@ import javax.xml.bind.annotation.XmlType;
 @XmlType(name = "AxEngineState", namespace = "http://www.onap.org/policy/apex-pdp")
 public enum AxEngineState {
     /** The state of the engine is not known. */
-    UNDEFINED,
+    UNDEFINED(0),
     /** The engine is stopped. */
-    STOPPED,
+    STOPPED(1),
     /** The engine is running and is waiting to execute a policy. */
-    READY,
+    READY(2),
     /** The engine is running and is executing a policy. */
-    EXECUTING,
-    /** The engine has been ordered to stop and is stoping. */
-    STOPPING;
-}
+    EXECUTING(3),
+    /** The engine has been ordered to stop and is stopping. */
+    STOPPING(4);
+
+    private final int stateIdentifier;
+
+    AxEngineState(int stateIdentifier) {
+        this.stateIdentifier = stateIdentifier;
+    }
+
+    public int getStateIdentifier() {
+        return stateIdentifier;
+    }
+}
\ No newline at end of file
diff --git a/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineStats.java b/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineStats.java
index 916525900..39a90800d 100644
--- a/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineStats.java
+++ b/model/engine-model/src/main/java/org/onap/policy/apex/model/enginemodel/concepts/AxEngineStats.java
@@ -2,6 +2,7 @@
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
  *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2022 Bell Canada.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +22,8 @@
 
 package org.onap.policy.apex.model.enginemodel.concepts;
 
+import io.prometheus.client.Gauge;
+import io.prometheus.client.Histogram;
 import java.text.SimpleDateFormat;
 import java.util.List;
 import javax.persistence.Column;
@@ -59,6 +62,22 @@ import org.onap.policy.common.utils.validation.Assertions;
 public class AxEngineStats extends AxConcept {
     private static final long serialVersionUID = -6981129081962785368L;
     private static final int HASH_CODE_PRIME = 32;
+    static final String ENGINE_INSTANCE_ID = "engine_instance_id";
+    static final Gauge ENGINE_EVENTS_EXECUTED_COUNT = Gauge.build().name("apex_engine_events_executed_count")
+            .labelNames(ENGINE_INSTANCE_ID)
+            .help("Total number of APEX events processed by the engine.").register();
+    static final Gauge ENGINE_UPTIME = Gauge.build().name("apex_engine_uptime")
+            .labelNames(ENGINE_INSTANCE_ID)
+            .help("Time elapsed since the engine was started.").register();
+    static final Gauge ENGINE_START_TIMESTAMP = Gauge.build().name("apex_engine_last_start_timestamp_epoch")
+            .labelNames(ENGINE_INSTANCE_ID)
+            .help("Epoch timestamp of the instance when engine was last started.").register();
+    static final Gauge ENGINE_AVG_EXECUTION_TIME = Gauge.build().name("apex_engine_average_execution_time_seconds")
+            .labelNames(ENGINE_INSTANCE_ID)
+            .help("Average time taken to execute an APEX policy in seconds.").register();
+    static final Histogram ENGINE_LAST_EXECUTION_TIME = Histogram.build()
+            .name("apex_engine_last_execution_time").labelNames(ENGINE_INSTANCE_ID)
+            .help("Time taken to execute the last APEX policy in seconds.").register();
 
     @EmbeddedId
     @XmlElement(name = "key", required = true)
@@ -104,6 +123,22 @@ public class AxEngineStats extends AxConcept {
         upTime = 0;
         lastEnterTime = 0;
         lastStart = 0;
+        initEngineMetricsWithPrometheus();
+    }
+
+    /**
+     * Register the APEX engine metrics with Prometheus.
+     */
+    private void initEngineMetricsWithPrometheus() {
+        var engineId = getKey().getParentArtifactKey().getId();
+        if (engineId.startsWith(AxKey.NULL_KEY_NAME)) {
+            return;
+        }
+        ENGINE_UPTIME.labels(engineId).set(upTime / 1000d);
+        ENGINE_EVENTS_EXECUTED_COUNT.labels(engineId).set(this.eventCount);
+        ENGINE_START_TIMESTAMP.labels(engineId).set(this.lastStart);
+        ENGINE_AVG_EXECUTION_TIME.labels(engineId).set(this.averageExecutionTime / 1000d);
+        ENGINE_LAST_EXECUTION_TIME.labels(engineId).observe(this.lastExecutionTime / 1000d);
     }
 
     /**
@@ -147,6 +182,7 @@ public class AxEngineStats extends AxConcept {
         this.averageExecutionTime = averageExecutionTime;
         this.upTime = upTime;
         this.lastStart = lastStart;
+        initEngineMetricsWithPrometheus();
     }
 
     /**
@@ -218,6 +254,8 @@ public class AxEngineStats extends AxConcept {
      */
     public void setEventCount(final long eventCount) {
         this.eventCount = eventCount;
+        ENGINE_EVENTS_EXECUTED_COUNT.labels(getKey().getParentArtifactKey().getId())
+                .set(this.eventCount);
     }
 
     /**
@@ -236,6 +274,8 @@ public class AxEngineStats extends AxConcept {
      */
     public void setLastExecutionTime(final long lastExecutionTime) {
         this.lastExecutionTime = lastExecutionTime;
+        ENGINE_LAST_EXECUTION_TIME.labels(getKey().getParentArtifactKey().getId())
+                .observe(this.lastExecutionTime / 1000d);
     }
 
     /**
@@ -254,6 +294,8 @@ public class AxEngineStats extends AxConcept {
      */
     public void setAverageExecutionTime(final double averageExecutionTime) {
         this.averageExecutionTime = averageExecutionTime;
+        ENGINE_AVG_EXECUTION_TIME.labels(getKey().getParentArtifactKey().getId())
+                .set(this.averageExecutionTime / 1000d);
     }
 
     /**
@@ -275,6 +317,7 @@ public class AxEngineStats extends AxConcept {
      */
     public void setUpTime(final long upTime) {
         this.upTime = upTime;
+        ENGINE_UPTIME.labels(getKey().getParentArtifactKey().getId()).set(this.upTime / 1000d);
     }
 
     /**
@@ -284,6 +327,7 @@ public class AxEngineStats extends AxConcept {
      */
     private void setLastStart(final long lastStart) {
         this.lastStart = lastStart;
+        ENGINE_START_TIMESTAMP.labels(getKey().getParentArtifactKey().getId()).set(this.lastStart);
     }
 
     /**
@@ -306,6 +350,7 @@ public class AxEngineStats extends AxConcept {
         upTime = 0;
         lastEnterTime = 0;
         lastStart = 0;
+        initEngineMetricsWithPrometheus();
     }
 
     /**
@@ -321,6 +366,7 @@ public class AxEngineStats extends AxConcept {
         }
         lastEnterTime = now;
         timeStamp = now;
+        ENGINE_EVENTS_EXECUTED_COUNT.labels(getKey().getParentArtifactKey().getId()).set(this.eventCount);
     }
 
     /**
@@ -329,10 +375,14 @@ public class AxEngineStats extends AxConcept {
     public synchronized void executionExit() {
         final long now = System.currentTimeMillis();
         lastExecutionTime = now - lastEnterTime;
+        ENGINE_LAST_EXECUTION_TIME.labels(getKey().getParentArtifactKey().getId())
+                .observe(this.lastExecutionTime / 1000d);
 
         averageExecutionTime = ((averageExecutionTime * (eventCount - 1.0)) + lastExecutionTime) / eventCount;
         lastEnterTime = 0;
         timeStamp = System.currentTimeMillis();
+        ENGINE_AVG_EXECUTION_TIME.labels(getKey().getParentArtifactKey().getId())
+                .set(this.averageExecutionTime / 1000d);
     }
 
     /**
@@ -352,6 +402,7 @@ public class AxEngineStats extends AxConcept {
         timeStamp = now;
         upTime += (timeStamp - this.getLastStart());
         this.setLastStart(0);
+        ENGINE_UPTIME.labels(getKey().getParentArtifactKey().getId()).set(this.upTime / 1000d);
     }
 
     /**
@@ -417,6 +468,7 @@ public class AxEngineStats extends AxConcept {
         copy.setAverageExecutionTime(averageExecutionTime);
         copy.setUpTime(upTime);
         copy.setLastStart(lastStart);
+        initEngineMetricsWithPrometheus();
 
         return copy;
     }
@@ -514,4 +566,4 @@ public class AxEngineStats extends AxConcept {
 
         return Long.compare(lastStart, other.lastStart);
     }
-}
+}
\ No newline at end of file