Enable metrics for core queues

The following queues will provide metrics:

* index_batch
* index_interactive
* receive_commits
* send_email
* ssh_batch_worker
* ssh_command_start
* ssh_interactive_worker
* ssh_stream_worker

For each queue following metrics are available:

* active_threads - Number of threads that are actively executing tasks
* max_pool_size - Maximum allowed number of threads in the pool
* pool_size - Current number of threads in the pool
* scheduled_tasks - Number of scheduled tasks in the queue
* total_completed_tasks_count - Total number of tasks that have completed execution
* total_scheduled_tasks_count - Total number of tasks that have been scheduled

Change-Id: I9430c2a90d1fb07630c1c8b599abf6dd18e01b2d
Signed-off-by: Eryk Szymanski <eryksz@gmail.com>

Documentation/metrics.txt

@@ -53,14 +53,28 @@ objects needing finalization.
 * `query/query_latency`: Successful query latency, accumulated over the life
 of the process.
 
-=== Work Queue
+=== Core Queues
 
-* `queue/work_queue/pool_size`: Current number of threads in the pool
-* `queue/work_queue/max_pool_size`: Maximum allowed number of threads in the pool
-* `queue/work_queue/active_threads`: Number of threads that are actively executing tasks
-* `queue/work_queue/scheduled_tasks`: Number of scheduled tasks in the queue
-* `queue/work_queue/total_scheduled_tasks_count`: Total number of tasks that have been scheduled
-* `queue/work_queue/total_completed_tasks_count`: Total number of tasks that have completed execution
+The following queues support metrics:
+
+* default `WorkQueue`
+* index batch
+* index interactive
+* receive commits
+* send email
+* ssh batch worker
+* ssh command start
+* ssh interactive worker
+* ssh stream worker
+
+Each queue provides the following metrics:
+
+* `queue/<queue_name>/pool_size`: Current number of threads in the pool
+* `queue/<queue_name>/max_pool_size`: Maximum allowed number of threads in the pool
+* `queue/<queue_name>/active_threads`: Number of threads that are actively executing tasks
+* `queue/<queue_name>/scheduled_tasks`: Number of scheduled tasks in the queue
+* `queue/<queue_name>/total_scheduled_tasks_count`: Total number of tasks that have been scheduled
+* `queue/<queue_name>/total_completed_tasks_count`: Total number of tasks that have completed execution
 
 === SSH sessions
 

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommitsExecutorModule.java

@@ -41,7 +41,7 @@ public class ReceiveCommitsExecutorModule extends AbstractModule {
     int poolSize =
         config.getInt(
             "receive", null, "threadPoolSize", Runtime.getRuntime().availableProcessors());
-    return queues.createQueue(poolSize, "ReceiveCommits");
+    return queues.createQueue(poolSize, "ReceiveCommits", true);
   }
 
   @Provides
@@ -53,7 +53,7 @@ public class ReceiveCommitsExecutorModule extends AbstractModule {
     if (poolSize == 0) {
       return MoreExecutors.newDirectExecutorService();
     }
-    return queues.createQueue(poolSize, "SendEmail");
+    return queues.createQueue(poolSize, "SendEmail", true);
   }
 
   @Provides

gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java

@@ -181,7 +181,8 @@ public class IndexModule extends LifecycleModule {
     if (threads <= 0) {
       threads = Runtime.getRuntime().availableProcessors() / 2 + 1;
     }
-    return MoreExecutors.listeningDecorator(workQueue.createQueue(threads, "Index-Interactive"));
+    return MoreExecutors.listeningDecorator(
+        workQueue.createQueue(threads, "Index-Interactive", true));
   }
 
   @Provides
@@ -199,7 +200,8 @@ public class IndexModule extends LifecycleModule {
     if (batchThreads <= 0) {
       batchThreads = Runtime.getRuntime().availableProcessors();
     }
-    return MoreExecutors.listeningDecorator(workQueue.createQueue(batchThreads, "Index-Batch"));
+    return MoreExecutors.listeningDecorator(
+        workQueue.createQueue(batchThreads, "Index-Batch", true));
   }
 
   @Singleton

gerrit-sshd/src/main/java/com/google/gerrit/sshd/CommandExecutorQueueProvider.java

@@ -43,9 +43,9 @@ public class CommandExecutorQueueProvider implements QueueProvider {
       poolSize += batchThreads;
     }
     int interactiveThreads = Math.max(1, poolSize - batchThreads);
-    interactiveExecutor = queues.createQueue(interactiveThreads, "SSH-Interactive-Worker");
+    interactiveExecutor = queues.createQueue(interactiveThreads, "SSH-Interactive-Worker", true);
     if (batchThreads != 0) {
-      batchExecutor = queues.createQueue(batchThreads, "SSH-Batch-Worker");
+      batchExecutor = queues.createQueue(batchThreads, "SSH-Batch-Worker", true);
       setThreadFactory(batchExecutor);
     } else {
       batchExecutor = interactiveExecutor;

gerrit-sshd/src/main/java/com/google/gerrit/sshd/CommandFactoryProvider.java

@@ -76,7 +76,7 @@ class CommandFactoryProvider implements Provider<CommandFactory>, LifecycleListe
     createCommandInterceptor = i;
 
     int threads = cfg.getInt("sshd", "commandStartThreads", 2);
-    startExecutor = workQueue.createQueue(threads, "SshCommandStart");
+    startExecutor = workQueue.createQueue(threads, "SshCommandStart", true);
     destroyExecutor =
         Executors.newSingleThreadExecutor(
             new ThreadFactoryBuilder()

gerrit-sshd/src/main/java/com/google/gerrit/sshd/StreamCommandExecutorProvider.java

@@ -36,7 +36,7 @@ class StreamCommandExecutorProvider implements Provider<WorkQueue.Executor> {
   public WorkQueue.Executor get() {
     final WorkQueue.Executor executor;
 
-    executor = queues.createQueue(poolSize, "SSH-Stream-Worker");
+    executor = queues.createQueue(poolSize, "SSH-Stream-Worker", true);
 
     final ThreadFactory parent = executor.getThreadFactory();
     executor.setThreadFactory(