add actor metrics

dist/pom.xml

@@ -244,7 +244,7 @@
               <goal>assemble</goal>
             </goals>
             <phase>package</phase>
-            <configuration />
+            <configuration></configuration>
           </execution>
         </executions>
       </plugin>

gateway-protocol-impl/pom.xml

@@ -105,7 +105,7 @@
                 <phase>generate-sources</phase>
                 <configuration>
                   <target>
-                    <copy failonerror="true" file="${project.build.directory}/generated-sources/protobuf/go/gateway.pb.go" tofile="${maven.multiModuleProjectDirectory}/clients/go/pkg/pb/gateway.pb.go" />
+                    <copy failonerror="true" file="${project.build.directory}/generated-sources/protobuf/go/gateway.pb.go" tofile="${maven.multiModuleProjectDirectory}/clients/go/pkg/pb/gateway.pb.go"></copy>
                   </target>
                 </configuration>
               </execution>

util/pom.xml

@@ -20,6 +20,10 @@
       <groupId>org.agrona</groupId>
       <artifactId>agrona</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.prometheus</groupId>
+      <artifactId>simpleclient</artifactId>
+    </dependency>
 
     <dependency>
       <groupId>org.slf4j</groupId>

util/src/main/java/io/camunda/zeebe/util/sched/ActorMetrics.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH under
+ * one or more contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright ownership.
+ * Licensed under the Zeebe Community License 1.1. You may not use this file
+ * except in compliance with the Zeebe Community License 1.1.
+ */
+package io.camunda.zeebe.util.sched;
+
+import io.prometheus.client.Counter;
+import io.prometheus.client.Histogram;
+
+public class ActorMetrics {
+
+  private static final Histogram EXECUTION_LATENCY =
+      Histogram.build()
+          .namespace("zeebe")
+          .name("sched_task_execution_latency")
+          .help("Latency to execute")
+          .labelNames("actorName")
+          .register();
+
+  private static final Counter EXECUTION_COUNT =
+      Counter.build()
+          .namespace("zeebe")
+          .name("sched_task_execution_count")
+          .labelNames("actorName")
+          .register();
+
+  public Histogram.Timer startExecutionTimer(final String name) {
+    return EXECUTION_LATENCY.labels(name).startTimer();
+  }
+
+  public void countExecution(final String name) {
+    EXECUTION_COUNT.labels(name).inc();
+  }
+}

util/src/main/java/io/camunda/zeebe/util/sched/ActorThread.java

@@ -25,6 +25,7 @@
 
 public class ActorThread extends Thread implements Consumer<Runnable> {
   static final Unsafe UNSAFE = UnsafeAccess.UNSAFE;
+  static final ActorMetrics ACTOR_METRICS = new ActorMetrics();
   private static final long STATE_OFFSET;
   private static final Logger LOG = Loggers.ACTOR_LOGGER;
   private static final FatalErrorHandler FATAL_ERROR_HANDLER = FatalErrorHandler.withLogger(LOG);
@@ -77,7 +78,12 @@ private void doWork() {
 
     if (currentTask != null) {
       try {
-        executeCurrentTask();
+        final var actorName = currentTask.actor.getName();
+        ACTOR_METRICS.countExecution(actorName);
+        try (final var timer = ACTOR_METRICS.startExecutionTimer(actorName)) {
+          executeCurrentTask();
+        }
+
       } finally {
         taskScheduler.onTaskReleased(currentTask);
       }