Merge pull request #1953 from metamx/taskRunnerResourceManagement

Move resource managemnt to be the responsibility of the TaskRunner

indexing-service/src/main/java/io/druid/indexing/overlord/ForkingTaskRunner.java

@@ -52,6 +52,7 @@ import io.druid.indexing.common.TaskStatus;
 import io.druid.indexing.common.config.TaskConfig;
 import io.druid.indexing.common.task.Task;
 import io.druid.indexing.common.tasklogs.LogUtils;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 import io.druid.indexing.overlord.config.ForkingTaskRunnerConfig;
 import io.druid.indexing.worker.config.WorkerConfig;
 import io.druid.query.DruidMetrics;
@@ -542,9 +543,9 @@ public class ForkingTaskRunner implements TaskRunner, TaskLogStreamer
   }
 
   @Override
-  public Collection<ZkWorker> getWorkers()
+  public Optional<ScalingStats> getScalingStats()
   {
-    return ImmutableList.of();
+    return Optional.absent();
   }
 
   @Override

indexing-service/src/main/java/io/druid/indexing/overlord/ForkingTaskRunnerFactory.java

@@ -31,8 +31,8 @@ import io.druid.tasklogs.TaskLogPusher;
 import java.util.Properties;
 
 /**
-*/
+ */
-public class ForkingTaskRunnerFactory implements TaskRunnerFactory
+public class ForkingTaskRunnerFactory implements TaskRunnerFactory<ForkingTaskRunner>
 {
   private final ForkingTaskRunnerConfig config;
   private final TaskConfig taskConfig;
@@ -51,7 +51,8 @@ public class ForkingTaskRunnerFactory implements TaskRunnerFactory
       final ObjectMapper jsonMapper,
       final TaskLogPusher persistentTaskLogs,
       @Self DruidNode node
-  ) {
+  )
+  {
     this.config = config;
     this.taskConfig = taskConfig;
     this.workerConfig = workerConfig;
@@ -62,7 +63,7 @@ public class ForkingTaskRunnerFactory implements TaskRunnerFactory
   }
 
   @Override
-  public TaskRunner build()
+  public ForkingTaskRunner build()
   {
     return new ForkingTaskRunner(config, taskConfig, workerConfig, props, persistentTaskLogs, jsonMapper, node);
   }

indexing-service/src/main/java/io/druid/indexing/overlord/RemoteTaskRunner.java

@@ -53,9 +53,12 @@ import com.metamx.http.client.Request;
 import com.metamx.http.client.response.InputStreamResponseHandler;
 import com.metamx.http.client.response.StatusResponseHandler;
 import com.metamx.http.client.response.StatusResponseHolder;
+import io.druid.concurrent.Execs;
 import io.druid.curator.cache.PathChildrenCacheFactory;
 import io.druid.indexing.common.TaskStatus;
 import io.druid.indexing.common.task.Task;
+import io.druid.indexing.overlord.autoscaling.ResourceManagementStrategy;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 import io.druid.indexing.overlord.config.RemoteTaskRunnerConfig;
 import io.druid.indexing.overlord.setup.WorkerBehaviorConfig;
 import io.druid.indexing.overlord.setup.WorkerSelectStrategy;
@@ -103,7 +106,6 @@ import java.util.concurrent.TimeUnit;
  * <p/>
  * The RemoteTaskRunner will assign tasks to a node until the node hits capacity. At that point, task assignment will
  * fail. The RemoteTaskRunner depends on another component to create additional worker resources.
- * For example, {@link io.druid.indexing.overlord.autoscaling.ResourceManagementScheduler} can take care of these duties.
  * <p/>
  * If a worker node becomes inexplicably disconnected from Zk, the RemoteTaskRunner will fail any tasks associated with the
  * worker after waiting for RemoteTaskRunnerConfig.taskCleanupTimeout for the worker to show up.
@@ -150,6 +152,7 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
   private final ListeningScheduledExecutorService cleanupExec;
 
   private final ConcurrentMap<String, ScheduledFuture> removedWorkerCleanups = new ConcurrentHashMap<>();
+  private final ResourceManagementStrategy<RemoteTaskRunner> resourceManagement;
 
   public RemoteTaskRunner(
       ObjectMapper jsonMapper,
@@ -159,7 +162,8 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
       PathChildrenCacheFactory pathChildrenCacheFactory,
       HttpClient httpClient,
       Supplier<WorkerBehaviorConfig> workerConfigRef,
-      ScheduledExecutorService cleanupExec
+      ScheduledExecutorService cleanupExec,
+      ResourceManagementStrategy<RemoteTaskRunner> resourceManagement
   )
   {
     this.jsonMapper = jsonMapper;
@@ -172,6 +176,7 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
     this.httpClient = httpClient;
     this.workerConfigRef = workerConfigRef;
     this.cleanupExec = MoreExecutors.listeningDecorator(cleanupExec);
+    this.resourceManagement = resourceManagement;
   }
 
   @LifecycleStart
@@ -284,6 +289,7 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
           waitingForMonitor.wait();
         }
       }
+      resourceManagement.startManagement(this);
       started = true;
     }
     catch (Exception e) {
@@ -299,6 +305,9 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
         return;
       }
       started = false;
+
+      resourceManagement.stopManagement();
+
       for (ZkWorker zkWorker : zkWorkers.values()) {
         zkWorker.close();
       }
@@ -315,7 +324,6 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
     return ImmutableList.of();
   }
 
-  @Override
   public Collection<ZkWorker> getWorkers()
   {
     return ImmutableList.copyOf(zkWorkers.values());
@@ -340,6 +348,12 @@ public class RemoteTaskRunner implements TaskRunner, TaskLogStreamer
     return ImmutableList.copyOf(Iterables.concat(pendingTasks.values(), runningTasks.values(), completeTasks.values()));
   }
 
+  @Override
+  public Optional<ScalingStats> getScalingStats()
+  {
+    return Optional.of(resourceManagement.getStats());
+  }
+
   public ZkWorker findWorkerRunningTask(String taskId)
   {
     for (ZkWorker zkWorker : zkWorkers.values()) {

indexing-service/src/main/java/io/druid/indexing/overlord/RemoteTaskRunnerFactory.java

@@ -23,9 +23,16 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Supplier;
 import com.google.inject.Inject;
 import com.metamx.common.concurrent.ScheduledExecutorFactory;
+import com.metamx.common.logger.Logger;
 import com.metamx.http.client.HttpClient;
 import io.druid.curator.cache.SimplePathChildrenCacheFactory;
 import io.druid.guice.annotations.Global;
+import io.druid.indexing.overlord.autoscaling.NoopResourceManagementStrategy;
+import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerConfig;
+import io.druid.indexing.overlord.autoscaling.ResourceManagementStrategy;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
+import io.druid.indexing.overlord.autoscaling.SimpleResourceManagementConfig;
+import io.druid.indexing.overlord.autoscaling.SimpleResourceManagementStrategy;
 import io.druid.indexing.overlord.config.RemoteTaskRunnerConfig;
 import io.druid.indexing.overlord.setup.WorkerBehaviorConfig;
 import io.druid.server.initialization.IndexerZkConfig;
@@ -35,8 +42,9 @@ import java.util.concurrent.ScheduledExecutorService;
 
 /**
  */
-public class RemoteTaskRunnerFactory implements TaskRunnerFactory
+public class RemoteTaskRunnerFactory implements TaskRunnerFactory<RemoteTaskRunner>
 {
+  private static final Logger LOG = new Logger(RemoteTaskRunnerFactory.class);
   private final CuratorFramework curator;
   private final RemoteTaskRunnerConfig remoteTaskRunnerConfig;
   private final IndexerZkConfig zkPaths;
@@ -44,6 +52,9 @@ public class RemoteTaskRunnerFactory implements TaskRunnerFactory
   private final HttpClient httpClient;
   private final Supplier<WorkerBehaviorConfig> workerConfigRef;
   private final ScheduledExecutorService cleanupExec;
+  private final SimpleResourceManagementConfig config;
+  private final ResourceManagementSchedulerConfig resourceManagementSchedulerConfig;
+  private final ScheduledExecutorService exec;
 
   @Inject
   public RemoteTaskRunnerFactory(
@@ -53,7 +64,10 @@ public class RemoteTaskRunnerFactory implements TaskRunnerFactory
       final ObjectMapper jsonMapper,
       @Global final HttpClient httpClient,
       final Supplier<WorkerBehaviorConfig> workerConfigRef,
-      ScheduledExecutorFactory factory
+      final ScheduledExecutorFactory factory,
+      final SimpleResourceManagementConfig config,
+      final ResourceManagementSchedulerConfig resourceManagementSchedulerConfig,
+      final ScheduledExecutorService exec
   )
   {
     this.curator = curator;
@@ -62,12 +76,26 @@ public class RemoteTaskRunnerFactory implements TaskRunnerFactory
     this.jsonMapper = jsonMapper;
     this.httpClient = httpClient;
     this.workerConfigRef = workerConfigRef;
-    this.cleanupExec = factory.create(1,"RemoteTaskRunner-Scheduled-Cleanup--%d");
+    this.cleanupExec = factory.create(1, "RemoteTaskRunner-Scheduled-Cleanup--%d");
+    this.config = config;
+    this.resourceManagementSchedulerConfig = resourceManagementSchedulerConfig;
+    this.exec = exec;
   }
 
   @Override
-  public TaskRunner build()
+  public RemoteTaskRunner build()
   {
+    final ResourceManagementStrategy<RemoteTaskRunner> resourceManagementStrategy;
+    if (resourceManagementSchedulerConfig.isDoAutoscale()) {
+      resourceManagementStrategy = new SimpleResourceManagementStrategy(
+          config,
+          workerConfigRef,
+          resourceManagementSchedulerConfig,
+          exec
+      );
+    } else {
+      resourceManagementStrategy = new NoopResourceManagementStrategy<>();
+    }
     return new RemoteTaskRunner(
         jsonMapper,
         remoteTaskRunnerConfig,
@@ -79,7 +107,8 @@ public class RemoteTaskRunnerFactory implements TaskRunnerFactory
             .build(),
         httpClient,
         workerConfigRef,
-        cleanupExec
+        cleanupExec,
+        resourceManagementStrategy
     );
   }
 }

indexing-service/src/main/java/io/druid/indexing/overlord/TaskMaster.java

@@ -22,8 +22,6 @@ package io.druid.indexing.overlord;
 import com.google.common.base.Optional;
 import com.google.common.base.Throwables;
 import com.google.inject.Inject;
-import com.metamx.common.concurrent.ScheduledExecutorFactory;
-import com.metamx.common.concurrent.ScheduledExecutors;
 import com.metamx.common.lifecycle.Lifecycle;
 import com.metamx.common.lifecycle.LifecycleStart;
 import com.metamx.common.lifecycle.LifecycleStop;
@@ -34,8 +32,7 @@ import io.druid.guice.annotations.Self;
 import io.druid.indexing.common.actions.TaskActionClient;
 import io.druid.indexing.common.actions.TaskActionClientFactory;
 import io.druid.indexing.common.task.Task;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementScheduler;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerFactory;
 import io.druid.indexing.overlord.config.TaskQueueConfig;
 import io.druid.server.DruidNode;
 import io.druid.server.initialization.IndexerZkConfig;
@@ -64,7 +61,6 @@ public class TaskMaster
   private volatile boolean leading = false;
   private volatile TaskRunner taskRunner;
   private volatile TaskQueue taskQueue;
-  private volatile ResourceManagementScheduler resourceManagementScheduler;
 
   private static final EmittingLogger log = new EmittingLogger(TaskMaster.class);
 
@@ -77,7 +73,6 @@ public class TaskMaster
       @Self final DruidNode node,
       final IndexerZkConfig zkPaths,
       final TaskRunnerFactory runnerFactory,
-      final ResourceManagementSchedulerFactory managementSchedulerFactory,
       final CuratorFramework curator,
       final ServiceAnnouncer serviceAnnouncer,
       final ServiceEmitter emitter
@@ -118,14 +113,6 @@ public class TaskMaster
                    .emit();
               }
               leaderLifecycle.addManagedInstance(taskRunner);
-              if (taskRunner instanceof RemoteTaskRunner) {
-                final ScheduledExecutorFactory executorFactory = ScheduledExecutors.createFactory(leaderLifecycle);
-                resourceManagementScheduler = managementSchedulerFactory.build(
-                    (RemoteTaskRunner) taskRunner,
-                    executorFactory
-                );
-                leaderLifecycle.addManagedInstance(resourceManagementScheduler);
-              }
               leaderLifecycle.addManagedInstance(taskQueue);
               leaderLifecycle.addHandler(
                   new Lifecycle.Handler()
@@ -285,10 +272,10 @@ public class TaskMaster
     }
   }
 
-  public Optional<ResourceManagementScheduler> getResourceManagementScheduler()
+  public Optional<ScalingStats> getScalingStats()
   {
     if (leading) {
-      return Optional.fromNullable(resourceManagementScheduler);
+      return taskRunner.getScalingStats();
     } else {
       return Optional.absent();
     }

indexing-service/src/main/java/io/druid/indexing/overlord/TaskRunner.java

@@ -19,10 +19,12 @@
 
 package io.druid.indexing.overlord;
 
+import com.google.common.base.Optional;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.metamx.common.Pair;
 import io.druid.indexing.common.TaskStatus;
 import io.druid.indexing.common.task.Task;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 
 import java.util.Collection;
 import java.util.List;
@@ -45,7 +47,7 @@ public interface TaskRunner
    *
    * @return task status, eventually
    */
-  public ListenableFuture<TaskStatus> run(Task task);
+  ListenableFuture<TaskStatus> run(Task task);
 
   /**
    * Inform the task runner it can clean up any resources associated with a task. This implies shutdown of any
@@ -53,19 +55,24 @@ public interface TaskRunner
    *
    * @param taskid task ID to clean up resources for
    */
-  public void shutdown(String taskid);
+  void shutdown(String taskid);
 
   /**
    * Stop this task runner. This may block until currently-running tasks can be gracefully stopped. After calling
    * stopping, "run" will not accept further tasks.
    */
-  public void stop();
+  void stop();
 
-  public Collection<? extends TaskRunnerWorkItem> getRunningTasks();
+  Collection<? extends TaskRunnerWorkItem> getRunningTasks();
 
-  public Collection<? extends TaskRunnerWorkItem> getPendingTasks();
+  Collection<? extends TaskRunnerWorkItem> getPendingTasks();
 
-  public Collection<? extends TaskRunnerWorkItem> getKnownTasks();
+  Collection<? extends TaskRunnerWorkItem> getKnownTasks();
 
-  public Collection<ZkWorker> getWorkers();
+  /**
+   * Some runners are able to scale up and down their capacity in a dynamic manner. This returns stats on those activities
+   *
+   * @return ScalingStats if the runner has an underlying resource which can scale, Optional.absent() otherwise
+   */
+  Optional<ScalingStats> getScalingStats();
 }

indexing-service/src/main/java/io/druid/indexing/overlord/TaskRunnerFactory.java

@@ -19,7 +19,7 @@
 
 package io.druid.indexing.overlord;
 
-public interface TaskRunnerFactory
+public interface TaskRunnerFactory<T extends TaskRunner>
 {
-  public TaskRunner build();
+  T build();
 }

indexing-service/src/main/java/io/druid/indexing/overlord/ThreadPoolTaskRunner.java

@@ -19,11 +19,11 @@
 
 package io.druid.indexing.overlord;
 
+import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
-import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -33,7 +33,6 @@ import com.google.inject.Inject;
 import com.metamx.common.Pair;
 import com.metamx.common.lifecycle.LifecycleStop;
 import com.metamx.emitter.EmittingLogger;
-import com.metamx.emitter.service.AlertEvent;
 import com.metamx.emitter.service.ServiceEmitter;
 import com.metamx.emitter.service.ServiceMetricEvent;
 import io.druid.concurrent.Execs;
@@ -42,6 +41,7 @@ import io.druid.indexing.common.TaskToolbox;
 import io.druid.indexing.common.TaskToolboxFactory;
 import io.druid.indexing.common.config.TaskConfig;
 import io.druid.indexing.common.task.Task;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 import io.druid.query.NoopQueryRunner;
 import io.druid.query.Query;
 import io.druid.query.QueryRunner;
@@ -204,9 +204,9 @@ public class ThreadPoolTaskRunner implements TaskRunner, QuerySegmentWalker
   }
 
   @Override
-  public Collection<ZkWorker> getWorkers()
+  public Optional<ScalingStats> getScalingStats()
   {
-    return Lists.newArrayList();
+    return Optional.absent();
   }
 
   @Override

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/AutoScaler.java

@@ -34,17 +34,17 @@ import java.util.List;
 })
 public interface AutoScaler<T>
 {
-  public int getMinNumWorkers();
+  int getMinNumWorkers();
 
-  public int getMaxNumWorkers();
+  int getMaxNumWorkers();
 
-  public T getEnvConfig();
+  T getEnvConfig();
 
-  public AutoScalingData provision();
+  AutoScalingData provision();
 
-  public AutoScalingData terminate(List<String> ips);
+  AutoScalingData terminate(List<String> ips);
 
-  public AutoScalingData terminateWithIds(List<String> ids);
+  AutoScalingData terminateWithIds(List<String> ids);
 
   /**
    * Provides a lookup of ip addresses to node ids
@@ -53,7 +53,7 @@ public interface AutoScaler<T>
    *
    * @return node ids
    */
-  public List<String> ipToIdLookup(List<String> ips);
+  List<String> ipToIdLookup(List<String> ips);
 
   /**
    * Provides a lookup of node ids to ip addresses
@@ -62,5 +62,5 @@ public interface AutoScaler<T>
    *
    * @return IPs associated with the node
    */
-  public List<String> idToIpLookup(List<String> nodeIds);
+  List<String> idToIpLookup(List<String> nodeIds);
 }

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/NoopResourceManagementScheduler.java

@@ -1,52 +0,0 @@
-/*
- * Licensed to Metamarkets Group Inc. (Metamarkets) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. Metamarkets licenses this file
- * to you 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.
- */
-
-package io.druid.indexing.overlord.autoscaling;
-
-import com.metamx.common.logger.Logger;
-
-/**
- */
-public class NoopResourceManagementScheduler extends ResourceManagementScheduler
-{
-  private static final Logger log = new Logger(NoopResourceManagementScheduler.class);
-
-  public NoopResourceManagementScheduler()
-  {
-    super(null, null, null, null);
-  }
-
-  @Override
-  public void start()
-  {
-    log.info("Autoscaling is disabled.");
-  }
-
-  @Override
-  public void stop()
-  {
-    // do nothing
-  }
-
-  @Override
-  public ScalingStats getStats()
-  {
-    return new ScalingStats(0);
-  }
-}

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/NoopResourceManagementStrategy.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  Metamarkets licenses this file
+ * to you 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.
+ */
+
+package io.druid.indexing.overlord.autoscaling;
+
+import io.druid.indexing.overlord.TaskRunner;
+
+public class NoopResourceManagementStrategy<T extends TaskRunner> implements ResourceManagementStrategy<T>
+{
+  @Override
+  public void startManagement(T runner)
+  {
+
+  }
+
+  @Override
+  public void stopManagement()
+  {
+
+  }
+
+  @Override
+  public ScalingStats getStats()
+  {
+    return null;
+  }
+}

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/ResourceManagementScheduler.java

@@ -1,127 +0,0 @@
-/*
- * Licensed to Metamarkets Group Inc. (Metamarkets) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. Metamarkets licenses this file
- * to you 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.
- */
-
-package io.druid.indexing.overlord.autoscaling;
-
-import com.metamx.common.concurrent.ScheduledExecutors;
-import com.metamx.common.lifecycle.LifecycleStart;
-import com.metamx.common.lifecycle.LifecycleStop;
-import com.metamx.common.logger.Logger;
-import io.druid.granularity.PeriodGranularity;
-import io.druid.indexing.overlord.RemoteTaskRunner;
-import org.joda.time.DateTime;
-import org.joda.time.Duration;
-import org.joda.time.Period;
-
-import java.util.concurrent.ScheduledExecutorService;
-
-/**
- * The ResourceManagementScheduler schedules a check for when worker nodes should potentially be created or destroyed.
- * The ResourceManagementScheduler does not contain the logic to decide whether provision or termination should actually
- * occur. That decision is made in the {@link ResourceManagementStrategy}.
- */
-public class ResourceManagementScheduler
-{
-  private static final Logger log = new Logger(ResourceManagementScheduler.class);
-
-  private final RemoteTaskRunner taskRunner;
-  private final ResourceManagementStrategy resourceManagementStrategy;
-  private final ResourceManagementSchedulerConfig config;
-  private final ScheduledExecutorService exec;
-
-  private final Object lock = new Object();
-  private volatile boolean started = false;
-
-  public ResourceManagementScheduler(
-      RemoteTaskRunner taskRunner,
-      ResourceManagementStrategy resourceManagementStrategy,
-      ResourceManagementSchedulerConfig config,
-      ScheduledExecutorService exec
-  )
-  {
-    this.taskRunner = taskRunner;
-    this.resourceManagementStrategy = resourceManagementStrategy;
-    this.config = config;
-    this.exec = exec;
-  }
-
-  @LifecycleStart
-  public void start()
-  {
-    synchronized (lock) {
-      if (started) {
-        return;
-      }
-
-      log.info("Started Resource Management Scheduler");
-
-      ScheduledExecutors.scheduleAtFixedRate(
-          exec,
-          config.getProvisionPeriod().toStandardDuration(),
-          new Runnable()
-          {
-            @Override
-            public void run()
-            {
-              resourceManagementStrategy.doProvision(taskRunner);
-            }
-          }
-      );
-
-      // Schedule termination of worker nodes periodically
-      Period period = config.getTerminatePeriod();
-      PeriodGranularity granularity = new PeriodGranularity(period, config.getOriginTime(), null);
-      final long startTime = granularity.next(granularity.truncate(new DateTime().getMillis()));
-
-      ScheduledExecutors.scheduleAtFixedRate(
-          exec,
-          new Duration(System.currentTimeMillis(), startTime),
-          config.getTerminatePeriod().toStandardDuration(),
-          new Runnable()
-          {
-            @Override
-            public void run()
-            {
-              resourceManagementStrategy.doTerminate(taskRunner);
-            }
-          }
-      );
-
-      started = true;
-    }
-  }
-
-  @LifecycleStop
-  public void stop()
-  {
-    synchronized (lock) {
-      if (!started) {
-        return;
-      }
-      log.info("Stopping Resource Management Scheduler");
-      exec.shutdown();
-      started = false;
-    }
-  }
-
-  public ScalingStats getStats()
-  {
-    return resourceManagementStrategy.getStats();
-  }
-}

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/ResourceManagementSchedulerFactory.java

@@ -1,30 +0,0 @@
-/*
- * Licensed to Metamarkets Group Inc. (Metamarkets) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. Metamarkets licenses this file
- * to you 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.
- */
-
-package io.druid.indexing.overlord.autoscaling;
-
-import com.metamx.common.concurrent.ScheduledExecutorFactory;
-import io.druid.indexing.overlord.RemoteTaskRunner;
-
-/**
- */
-public interface ResourceManagementSchedulerFactory
-{
-  public ResourceManagementScheduler build(RemoteTaskRunner runner, ScheduledExecutorFactory executorFactory);
-}

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/ResourceManagementSchedulerFactoryImpl.java

@@ -1,54 +0,0 @@
-/*
- * Licensed to Metamarkets Group Inc. (Metamarkets) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. Metamarkets licenses this file
- * to you 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.
- */
-
-package io.druid.indexing.overlord.autoscaling;
-
-import com.google.inject.Inject;
-import com.metamx.common.concurrent.ScheduledExecutorFactory;
-import io.druid.indexing.overlord.RemoteTaskRunner;
-
-/**
- */
-public class ResourceManagementSchedulerFactoryImpl implements ResourceManagementSchedulerFactory
-{
-  private final ResourceManagementSchedulerConfig config;
-  private final ResourceManagementStrategy strategy;
-
-  @Inject
-  public ResourceManagementSchedulerFactoryImpl(
-      ResourceManagementStrategy strategy,
-      ResourceManagementSchedulerConfig config,
-      ScheduledExecutorFactory executorFactory
-  )
-  {
-    this.config = config;
-    this.strategy = strategy;
-  }
-
-  @Override
-  public ResourceManagementScheduler build(RemoteTaskRunner runner, ScheduledExecutorFactory executorFactory)
-  {
-    if (config.isDoAutoscale()) {
-      return new ResourceManagementScheduler(runner, strategy, config, executorFactory.create(1, "ScalingExec--%d"));
-    }
-    else {
-      return new NoopResourceManagementScheduler();
-    }
-  }
-}

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/ResourceManagementStrategy.java

@@ -19,17 +19,33 @@
 
 package io.druid.indexing.overlord.autoscaling;
 
-import io.druid.indexing.overlord.RemoteTaskRunner;
+import io.druid.indexing.overlord.TaskRunner;
 
 /**
  * The ResourceManagementStrategy decides if worker nodes should be provisioned or determined
  * based on the available tasks in the system and the state of the workers in the system.
+ * In general, the resource management is tied to the runner.
  */
-public interface ResourceManagementStrategy
+public interface ResourceManagementStrategy<T extends TaskRunner>
 {
-  public boolean doProvision(RemoteTaskRunner runner);
+  /**
+   * Equivalent to start() but requires a specific runner instance which holds state of interest.
+   * This method is intended to be called from the TaskRunner's lifecycle
+   *
+   * @param runner The TaskRunner state holder this strategy should use during execution
+   */
+  void startManagement(T runner);
 
-  public boolean doTerminate(RemoteTaskRunner runner);
+  /**
+   * Equivalent to stop()
+   * Should be called from TaskRunner's lifecycle
+   */
+  void stopManagement();
 
-  public ScalingStats getStats();
+  /**
+   * Get any interesting stats related to scaling
+   *
+   * @return The ScalingStats or `null` if nothing of interest
+   */
+  ScalingStats getStats();
 }

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/ScalingStats.java

@@ -23,6 +23,7 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.google.common.collect.Lists;
 import com.google.common.collect.MinMaxPriorityQueue;
+import com.google.common.collect.Ordering;
 import org.joda.time.DateTime;
 
 import java.util.Collections;
@@ -33,20 +34,20 @@ import java.util.List;
  */
 public class ScalingStats
 {
-  public static enum EVENT
+  public enum EVENT
   {
     PROVISION,
     TERMINATE
   }
 
-  private static final Comparator<ScalingEvent> comparator = new Comparator<ScalingEvent>()
+  private static final Comparator<ScalingEvent> COMPARATOR = new Ordering<ScalingEvent>()
   {
     @Override
     public int compare(ScalingEvent s1, ScalingEvent s2)
     {
-      return -s1.getTimestamp().compareTo(s2.getTimestamp());
+      return s2.getTimestamp().compareTo(s1.getTimestamp());
     }
-  };
+  }.nullsLast();
 
   private final Object lock = new Object();
 
@@ -55,10 +56,10 @@ public class ScalingStats
   public ScalingStats(int capacity)
   {
     if (capacity == 0) {
-      this.recentEvents = MinMaxPriorityQueue.orderedBy(comparator).create();
+      this.recentEvents = MinMaxPriorityQueue.orderedBy(COMPARATOR).create();
     } else {
       this.recentEvents = MinMaxPriorityQueue
-          .orderedBy(comparator)
+          .orderedBy(COMPARATOR)
           .maximumSize(capacity)
           .create();
     }
@@ -95,7 +96,7 @@ public class ScalingStats
   {
     synchronized (lock) {
       List<ScalingEvent> retVal = Lists.newArrayList(recentEvents);
-      Collections.sort(retVal, comparator);
+      Collections.sort(retVal, COMPARATOR);
       return retVal;
     }
   }

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/SimpleResourceManagementConfig.java

@@ -99,6 +99,7 @@ public class SimpleResourceManagementConfig
     return this;
   }
 
+  // Do not use this if possible. Assuming all workers will have the same port is bad for containers.
   public int getWorkerPort()
   {
     return workerPort;

indexing-service/src/main/java/io/druid/indexing/overlord/autoscaling/SimpleResourceManagementStrategy.java

@@ -29,25 +29,33 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import com.google.inject.Inject;
 import com.metamx.common.ISE;
+import com.metamx.common.concurrent.ScheduledExecutors;
 import com.metamx.emitter.EmittingLogger;
+import io.druid.granularity.PeriodGranularity;
 import io.druid.indexing.overlord.RemoteTaskRunner;
-import io.druid.indexing.overlord.RemoteTaskRunnerWorkItem;
 import io.druid.indexing.overlord.TaskRunnerWorkItem;
 import io.druid.indexing.overlord.ZkWorker;
 import io.druid.indexing.overlord.setup.WorkerBehaviorConfig;
 import org.joda.time.DateTime;
 import org.joda.time.Duration;
+import org.joda.time.Period;
 
 import java.util.Collection;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.ScheduledExecutorService;
 
 /**
  */
-public class SimpleResourceManagementStrategy implements ResourceManagementStrategy
+public class SimpleResourceManagementStrategy implements ResourceManagementStrategy<RemoteTaskRunner>
 {
   private static final EmittingLogger log = new EmittingLogger(SimpleResourceManagementStrategy.class);
 
+  private final ResourceManagementSchedulerConfig resourceManagementSchedulerConfig;
+  private final ScheduledExecutorService exec;
+
+  private volatile boolean started = false;
+
   private final SimpleResourceManagementConfig config;
   private final Supplier<WorkerBehaviorConfig> workerConfigRef;
   private final ScalingStats scalingStats;
@@ -63,19 +71,22 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
   @Inject
   public SimpleResourceManagementStrategy(
       SimpleResourceManagementConfig config,
-      Supplier<WorkerBehaviorConfig> workerConfigRef
+      Supplier<WorkerBehaviorConfig> workerConfigRef,
+      ResourceManagementSchedulerConfig resourceManagementSchedulerConfig,
+      ScheduledExecutorService exec
   )
   {
     this.config = config;
     this.workerConfigRef = workerConfigRef;
     this.scalingStats = new ScalingStats(config.getNumEventsToTrack());
+    this.resourceManagementSchedulerConfig = resourceManagementSchedulerConfig;
+    this.exec = exec;
   }
 
-  @Override
+  boolean doProvision(RemoteTaskRunner runner)
-  public boolean doProvision(RemoteTaskRunner runner)
   {
-    Collection<RemoteTaskRunnerWorkItem> pendingTasks = runner.getPendingTasks();
+    Collection<? extends TaskRunnerWorkItem> pendingTasks = runner.getPendingTasks();
-    Collection<ZkWorker> zkWorkers = runner.getWorkers();
+    Collection<ZkWorker> zkWorkers = getWorkers(runner);
     synchronized (lock) {
       boolean didProvision = false;
       final WorkerBehaviorConfig workerConfig = workerConfigRef.get();
@@ -140,10 +151,9 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
     }
   }
 
-  @Override
+  boolean doTerminate(RemoteTaskRunner runner)
-  public boolean doTerminate(RemoteTaskRunner runner)
   {
-    Collection<RemoteTaskRunnerWorkItem> pendingTasks = runner.getPendingTasks();
+    Collection<? extends TaskRunnerWorkItem> pendingTasks = runner.getPendingTasks();
     synchronized (lock) {
       final WorkerBehaviorConfig workerConfig = workerConfigRef.get();
       if (workerConfig == null) {
@@ -179,7 +189,7 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
       currentlyTerminating.clear();
       currentlyTerminating.addAll(stillExisting);
 
-      Collection<ZkWorker> workers = runner.getWorkers();
+      Collection<ZkWorker> workers = getWorkers(runner);
       updateTargetWorkerCount(workerConfig, pendingTasks, workers);
 
       if (currentlyTerminating.isEmpty()) {
@@ -237,6 +247,70 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
     }
   }
 
+  @Override
+  public void startManagement(final RemoteTaskRunner runner)
+  {
+    synchronized (lock) {
+      if (started) {
+        return;
+      }
+
+      log.info("Started Resource Management Scheduler");
+
+      ScheduledExecutors.scheduleAtFixedRate(
+          exec,
+          resourceManagementSchedulerConfig.getProvisionPeriod().toStandardDuration(),
+          new Runnable()
+          {
+            @Override
+            public void run()
+            {
+              doProvision(runner);
+            }
+          }
+      );
+
+      // Schedule termination of worker nodes periodically
+      Period period = resourceManagementSchedulerConfig.getTerminatePeriod();
+      PeriodGranularity granularity = new PeriodGranularity(
+          period,
+          resourceManagementSchedulerConfig.getOriginTime(),
+          null
+      );
+      final long startTime = granularity.next(granularity.truncate(new DateTime().getMillis()));
+
+      ScheduledExecutors.scheduleAtFixedRate(
+          exec,
+          new Duration(System.currentTimeMillis(), startTime),
+          resourceManagementSchedulerConfig.getTerminatePeriod().toStandardDuration(),
+          new Runnable()
+          {
+            @Override
+            public void run()
+            {
+              doTerminate(runner);
+            }
+          }
+      );
+
+      started = true;
+
+    }
+  }
+
+  @Override
+  public void stopManagement()
+  {
+    synchronized (lock) {
+      if (!started) {
+        return;
+      }
+      log.info("Stopping Resource Management Scheduler");
+      exec.shutdown();
+      started = false;
+    }
+  }
+
   @Override
   public ScalingStats getStats()
   {
@@ -281,7 +355,7 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
 
   private void updateTargetWorkerCount(
       final WorkerBehaviorConfig workerConfig,
-      final Collection<RemoteTaskRunnerWorkItem> pendingTasks,
+      final Collection<? extends TaskRunnerWorkItem> pendingTasks,
       final Collection<ZkWorker> zkWorkers
   )
   {
@@ -358,7 +432,7 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
     }
   }
 
-  private boolean hasTaskPendingBeyondThreshold(Collection<RemoteTaskRunnerWorkItem> pendingTasks)
+  private boolean hasTaskPendingBeyondThreshold(Collection<? extends TaskRunnerWorkItem> pendingTasks)
   {
     synchronized (lock) {
       long now = System.currentTimeMillis();
@@ -372,4 +446,9 @@ public class SimpleResourceManagementStrategy implements ResourceManagementStrat
       return false;
     }
   }
+
+  public Collection<ZkWorker> getWorkers(RemoteTaskRunner runner)
+  {
+    return runner.getWorkers();
+  }
 }

indexing-service/src/main/java/io/druid/indexing/overlord/http/OverlordResource.java

@@ -39,12 +39,13 @@ import io.druid.indexing.common.TaskStatus;
 import io.druid.indexing.common.actions.TaskActionClient;
 import io.druid.indexing.common.actions.TaskActionHolder;
 import io.druid.indexing.common.task.Task;
+import io.druid.indexing.overlord.RemoteTaskRunner;
 import io.druid.indexing.overlord.TaskMaster;
 import io.druid.indexing.overlord.TaskQueue;
 import io.druid.indexing.overlord.TaskRunner;
 import io.druid.indexing.overlord.TaskRunnerWorkItem;
 import io.druid.indexing.overlord.TaskStorageQueryAdapter;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementScheduler;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 import io.druid.indexing.overlord.setup.WorkerBehaviorConfig;
 import io.druid.metadata.EntryExistsException;
 import io.druid.tasklogs.TaskLogStreamer;
@@ -409,7 +410,18 @@ public class OverlordResource
           @Override
           public Response apply(TaskRunner taskRunner)
           {
-            return Response.ok(taskRunner.getWorkers()).build();
+            if (taskRunner instanceof RemoteTaskRunner) {
+              return Response.ok(((RemoteTaskRunner) taskRunner).getWorkers()).build();
+            } else {
+              log.debug(
+                  "Task runner [%s] of type [%s] does not support listing workers",
+                  taskRunner,
+                  taskRunner.getClass().getCanonicalName()
+              );
+              return Response.serverError()
+                             .entity(ImmutableMap.of("error", "Task Runner does not support worker listing"))
+                             .build();
+            }
           }
         }
     );
@@ -421,9 +433,9 @@ public class OverlordResource
   public Response getScalingState()
   {
     // Don't use asLeaderWith, since we want to return 200 instead of 503 when missing an autoscaler.
-    final Optional<ResourceManagementScheduler> rms = taskMaster.getResourceManagementScheduler();
+    final Optional<ScalingStats> rms = taskMaster.getScalingStats();
     if (rms.isPresent()) {
-      return Response.ok(rms.get().getStats()).build();
+      return Response.ok(rms.get()).build();
     } else {
       return Response.ok().build();
     }
@@ -563,7 +575,7 @@ public class OverlordResource
       }
       if (status.isPresent()) {
         data.put("statusCode", status.get().getStatusCode().toString());
-        if(status.get().isComplete()) {
+        if (status.get().isComplete()) {
           data.put("duration", status.get().getDuration());
         }
       }

indexing-service/src/main/java/io/druid/indexing/overlord/setup/WorkerSelectStrategy.java

@@ -48,7 +48,7 @@ public interface WorkerSelectStrategy
    *
    * @return A {@link io.druid.indexing.overlord.ImmutableZkWorker} to run the task if one is available.
    */
-  public Optional<ImmutableZkWorker> findWorkerForTask(
+  Optional<ImmutableZkWorker> findWorkerForTask(
       final RemoteTaskRunnerConfig config,
       final ImmutableMap<String, ImmutableZkWorker> zkWorkers,
       final Task task

indexing-service/src/test/java/io/druid/indexing/overlord/RemoteTaskRunnerTest.java

@@ -41,6 +41,9 @@ import io.druid.indexing.common.TestRealtimeTask;
 import io.druid.indexing.common.TestUtils;
 import io.druid.indexing.common.task.Task;
 import io.druid.indexing.common.task.TaskResource;
+import io.druid.indexing.overlord.autoscaling.NoopResourceManagementStrategy;
+import io.druid.indexing.overlord.autoscaling.ResourceManagementStrategy;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
 import io.druid.indexing.overlord.config.RemoteTaskRunnerConfig;
 import io.druid.indexing.overlord.setup.WorkerBehaviorConfig;
 import io.druid.indexing.worker.TaskAnnouncement;
@@ -475,7 +478,8 @@ public class RemoteTaskRunnerTest
         new SimplePathChildrenCacheFactory.Builder().build(),
         null,
         DSuppliers.of(new AtomicReference<>(WorkerBehaviorConfig.defaultConfig())),
-        ScheduledExecutors.fixed(1, "Remote-Task-Runner-Cleanup--%d")
+        ScheduledExecutors.fixed(1, "Remote-Task-Runner-Cleanup--%d"),
+        new NoopResourceManagementStrategy<RemoteTaskRunner>()
     );
 
     remoteTaskRunner.start();

indexing-service/src/test/java/io/druid/indexing/overlord/autoscaling/SimpleResourceManagementStrategyTest.java

@@ -27,6 +27,7 @@ import com.metamx.emitter.EmittingLogger;
 import com.metamx.emitter.service.ServiceEmitter;
 import com.metamx.emitter.service.ServiceEventBuilder;
 import io.druid.common.guava.DSuppliers;
+import io.druid.concurrent.Execs;
 import io.druid.indexing.common.TaskStatus;
 import io.druid.indexing.common.TestMergeTask;
 import io.druid.indexing.common.task.NoopTask;
@@ -45,6 +46,7 @@ import org.easymock.EasyMock;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 import org.joda.time.Period;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -53,6 +55,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicReference;
 
 /**
@@ -61,9 +64,9 @@ public class SimpleResourceManagementStrategyTest
 {
   private AutoScaler autoScaler;
   private Task testTask;
-  private SimpleResourceManagementConfig simpleResourceManagementConfig;
   private SimpleResourceManagementStrategy simpleResourceManagementStrategy;
   private AtomicReference<WorkerBehaviorConfig> workerConfig;
+  private ScheduledExecutorService executorService = Execs.scheduledSingleThreaded("test service");
 
   @Before
   public void setUp() throws Exception
@@ -75,7 +78,7 @@ public class SimpleResourceManagementStrategyTest
     testTask = new TestMergeTask(
         "task1",
         "dummyDs",
-        Lists.<DataSegment>newArrayList(
+        Lists.newArrayList(
             new DataSegment(
                 "dummyDs",
                 new Interval("2012-01-01/2012-01-02"),
@@ -92,13 +95,15 @@ public class SimpleResourceManagementStrategyTest
         indexSpec
     );
 
-    simpleResourceManagementConfig = new SimpleResourceManagementConfig()
+    final SimpleResourceManagementConfig simpleResourceManagementConfig = new SimpleResourceManagementConfig()
         .setWorkerIdleTimeout(new Period(0))
         .setMaxScalingDuration(new Period(1000))
         .setNumEventsToTrack(1)
         .setPendingTaskTimeout(new Period(0))
         .setWorkerVersion("");
 
+    final ResourceManagementSchedulerConfig schedulerConfig = new ResourceManagementSchedulerConfig();
+
     workerConfig = new AtomicReference<>(
         new WorkerBehaviorConfig(
             null,
@@ -108,10 +113,18 @@ public class SimpleResourceManagementStrategyTest
 
     simpleResourceManagementStrategy = new SimpleResourceManagementStrategy(
         simpleResourceManagementConfig,
-        DSuppliers.of(workerConfig)
+        DSuppliers.of(workerConfig),
+        schedulerConfig,
+        executorService
     );
   }
 
+  @After
+  public void tearDown()
+  {
+    executorService.shutdownNow();
+  }
+
   @Test
   public void testSuccessfulProvision() throws Exception
   {
@@ -120,16 +133,16 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
             .andReturn(Lists.<String>newArrayList());
     EasyMock.expect(autoScaler.provision()).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("aNode"))
+        new AutoScalingData(Lists.newArrayList("aNode"))
     );
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     );
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     );
@@ -156,16 +169,16 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
             .andReturn(Lists.<String>newArrayList()).times(2);
     EasyMock.expect(autoScaler.provision()).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("fake"))
+        new AutoScalingData(Lists.newArrayList("fake"))
     );
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     ).times(2);
@@ -212,17 +225,17 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.terminateWithIds(EasyMock.<List<String>>anyObject()))
             .andReturn(null);
     EasyMock.expect(autoScaler.provision()).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("fake"))
+        new AutoScalingData(Lists.newArrayList("fake"))
     );
     EasyMock.replay(autoScaler);
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     ).times(2);
@@ -268,17 +281,17 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.replay(autoScaler);
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     ).times(2);
-    EasyMock.expect(runner.markWorkersLazy((Predicate<ZkWorker>) EasyMock.anyObject(), EasyMock.anyInt())).andReturn(
+    EasyMock.expect(runner.markWorkersLazy(EasyMock.<Predicate<ZkWorker>>anyObject(), EasyMock.anyInt())).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     );
@@ -302,26 +315,26 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(0).times(2);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(1).times(2);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip")).times(2);
+            .andReturn(Lists.newArrayList("ip")).times(2);
     EasyMock.expect(autoScaler.terminate(EasyMock.<List<String>>anyObject())).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("ip"))
+        new AutoScalingData(Lists.newArrayList("ip"))
     );
     EasyMock.replay(autoScaler);
 
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     ).times(2);
     EasyMock.expect(runner.getLazyWorkers()).andReturn(Lists.<ZkWorker>newArrayList()).times(2);
-    EasyMock.expect(runner.markWorkersLazy((Predicate<ZkWorker>) EasyMock.anyObject(), EasyMock.anyInt())).andReturn(
+    EasyMock.expect(runner.markWorkersLazy(EasyMock.<Predicate<ZkWorker>>anyObject(), EasyMock.anyInt())).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(testTask)
         )
     );
@@ -354,12 +367,12 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(0);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(2);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip"));
+            .andReturn(Lists.newArrayList("ip"));
     EasyMock.replay(autoScaler);
 
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
@@ -370,7 +383,7 @@ public class SimpleResourceManagementStrategyTest
         )
     ).times(2);
     EasyMock.expect(runner.getLazyWorkers()).andReturn(Lists.<ZkWorker>newArrayList());
-    EasyMock.expect(runner.markWorkersLazy((Predicate<ZkWorker>) EasyMock.anyObject(), EasyMock.anyInt())).andReturn(
+    EasyMock.expect(runner.markWorkersLazy(EasyMock.<Predicate<ZkWorker>>anyObject(), EasyMock.anyInt())).andReturn(
         Collections.<ZkWorker>emptyList()
     );
     EasyMock.replay(runner);
@@ -384,7 +397,7 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(0);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(2);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip"));
+            .andReturn(Lists.newArrayList("ip"));
     EasyMock.replay(autoScaler);
 
     boolean provisionedSomething = simpleResourceManagementStrategy.doProvision(runner);
@@ -402,19 +415,19 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(0);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(2);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip"));
+            .andReturn(Lists.newArrayList("ip"));
     EasyMock.replay(autoScaler);
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.<RemoteTaskRunnerWorkItem>asList()
+        Collections.<RemoteTaskRunnerWorkItem>emptyList()
     ).times(3);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(NoopTask.create(), "h1", "i1", "0")
         )
     ).times(3);
     EasyMock.expect(runner.getLazyWorkers()).andReturn(Lists.<ZkWorker>newArrayList());
-    EasyMock.expect(runner.markWorkersLazy((Predicate<ZkWorker>) EasyMock.anyObject(), EasyMock.anyInt())).andReturn(
+    EasyMock.expect(runner.markWorkersLazy(EasyMock.<Predicate<ZkWorker>>anyObject(), EasyMock.anyInt())).andReturn(
         Collections.<ZkWorker>emptyList()
     );
     EasyMock.replay(runner);
@@ -430,7 +443,7 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(0);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(2);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip"));
+            .andReturn(Lists.newArrayList("ip"));
     EasyMock.replay(autoScaler);
     boolean provisionedSomething = simpleResourceManagementStrategy.doProvision(
         runner
@@ -443,13 +456,13 @@ public class SimpleResourceManagementStrategyTest
     EasyMock.expect(autoScaler.getMinNumWorkers()).andReturn(3);
     EasyMock.expect(autoScaler.getMaxNumWorkers()).andReturn(5);
     EasyMock.expect(autoScaler.ipToIdLookup(EasyMock.<List<String>>anyObject()))
-            .andReturn(Lists.<String>newArrayList("ip"));
+            .andReturn(Lists.newArrayList("ip"));
     EasyMock.expect(autoScaler.provision()).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("h3"))
+        new AutoScalingData(Lists.newArrayList("h3"))
     );
     // Should provision two new workers
     EasyMock.expect(autoScaler.provision()).andReturn(
-        new AutoScalingData(Lists.<String>newArrayList("h4"))
+        new AutoScalingData(Lists.newArrayList("h4"))
     );
     EasyMock.replay(autoScaler);
     provisionedSomething = simpleResourceManagementStrategy.doProvision(
@@ -468,12 +481,12 @@ public class SimpleResourceManagementStrategyTest
 
     RemoteTaskRunner runner = EasyMock.createMock(RemoteTaskRunner.class);
     EasyMock.expect(runner.getPendingTasks()).andReturn(
-        Arrays.asList(
+        Collections.singletonList(
             new RemoteTaskRunnerWorkItem(testTask.getId(), null).withQueueInsertionTime(new DateTime())
         )
     ).times(2);
     EasyMock.expect(runner.getWorkers()).andReturn(
-        Arrays.<ZkWorker>asList(
+        Collections.<ZkWorker>singletonList(
             new TestZkWorker(null)
         )
     ).times(1);

indexing-service/src/test/java/io/druid/indexing/overlord/http/OverlordResourceTest.java

@@ -20,13 +20,13 @@
 package io.druid.indexing.overlord.http;
 
 import com.google.common.base.Function;
+import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.metamx.common.Pair;
-import com.metamx.common.concurrent.ScheduledExecutorFactory;
 import com.metamx.common.guava.CloseQuietly;
 import com.metamx.emitter.EmittingLogger;
 import com.metamx.emitter.service.ServiceEmitter;
@@ -39,7 +39,6 @@ import io.druid.indexing.common.config.TaskStorageConfig;
 import io.druid.indexing.common.task.NoopTask;
 import io.druid.indexing.common.task.Task;
 import io.druid.indexing.overlord.HeapMemoryTaskStorage;
-import io.druid.indexing.overlord.RemoteTaskRunner;
 import io.druid.indexing.overlord.TaskLockbox;
 import io.druid.indexing.overlord.TaskMaster;
 import io.druid.indexing.overlord.TaskRunner;
@@ -47,10 +46,7 @@ import io.druid.indexing.overlord.TaskRunnerFactory;
 import io.druid.indexing.overlord.TaskRunnerWorkItem;
 import io.druid.indexing.overlord.TaskStorage;
 import io.druid.indexing.overlord.TaskStorageQueryAdapter;
-import io.druid.indexing.overlord.ZkWorker;
+import io.druid.indexing.overlord.autoscaling.ScalingStats;
-import io.druid.indexing.overlord.autoscaling.NoopResourceManagementScheduler;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementScheduler;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerFactory;
 import io.druid.indexing.overlord.config.TaskQueueConfig;
 import io.druid.server.DruidNode;
 import io.druid.server.initialization.IndexerZkConfig;
@@ -157,24 +153,14 @@ public class OverlordResourceTest
         taskActionClientFactory,
         druidNode,
         indexerZkConfig,
-        new TaskRunnerFactory()
+        new TaskRunnerFactory<MockTaskRunner>()
         {
           @Override
-          public TaskRunner build()
+          public MockTaskRunner build()
           {
             return new MockTaskRunner(runTaskCountDownLatches, taskCompletionCountDownLatches);
           }
         },
-        new ResourceManagementSchedulerFactory()
-        {
-          @Override
-          public ResourceManagementScheduler build(
-              RemoteTaskRunner runner, ScheduledExecutorFactory executorFactory
-          )
-          {
-            return new NoopResourceManagementScheduler();
-          }
-        },
         curator,
         new NoopServiceAnnouncer()
         {
@@ -195,7 +181,7 @@ public class OverlordResourceTest
     // basic task master lifecycle test
     taskMaster.start();
     announcementLatch.await();
-    while(!taskMaster.isLeading()){
+    while (!taskMaster.isLeading()) {
       // I believe the control will never reach here and thread will never sleep but just to be on safe side
       Thread.sleep(10);
     }
@@ -265,7 +251,8 @@ public class OverlordResourceTest
    * These method will not timeout until the condition is met so calling method should ensure timeout
    * This method also assumes that the task with given taskId is present
    * */
-  private void waitForTaskStatus(String taskId, TaskStatus.Status status) throws InterruptedException {
+  private void waitForTaskStatus(String taskId, TaskStatus.Status status) throws InterruptedException
+  {
     while (true) {
       Response response = overlordResource.getTaskStatus(taskId);
       if (status.equals(((TaskStatus) ((Map) response.getEntity()).get("status")).getStatusCode())) {
@@ -375,9 +362,9 @@ public class OverlordResourceTest
     }
 
     @Override
-    public Collection<ZkWorker> getWorkers()
+    public Optional<ScalingStats> getScalingStats()
     {
-      return ImmutableList.of();
+      return Optional.absent();
     }
   }
 }

services/src/main/java/io/druid/cli/CliOverlord.java

@@ -61,8 +61,6 @@ import io.druid.indexing.overlord.TaskRunnerFactory;
 import io.druid.indexing.overlord.TaskStorage;
 import io.druid.indexing.overlord.TaskStorageQueryAdapter;
 import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerConfig;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerFactory;
-import io.druid.indexing.overlord.autoscaling.ResourceManagementSchedulerFactoryImpl;
 import io.druid.indexing.overlord.autoscaling.ResourceManagementStrategy;
 import io.druid.indexing.overlord.autoscaling.SimpleResourceManagementConfig;
 import io.druid.indexing.overlord.autoscaling.SimpleResourceManagementStrategy;
@@ -141,9 +139,6 @@ public class CliOverlord extends ServerRunnable
             binder.bind(TaskActionToolbox.class).in(LazySingleton.class);
             binder.bind(TaskLockbox.class).in(LazySingleton.class);
             binder.bind(TaskStorageQueryAdapter.class).in(LazySingleton.class);
-            binder.bind(ResourceManagementSchedulerFactory.class)
-                  .to(ResourceManagementSchedulerFactoryImpl.class)
-                  .in(LazySingleton.class);
 
             binder.bind(ChatHandlerProvider.class).toProvider(Providers.<ChatHandlerProvider>of(null));