Fix handling of InterruptedException in WorkerTaskMonitor's mainLoop.

I believe this will fix #2664.

indexing-service/src/main/java/io/druid/indexing/worker/WorkerCuratorCoordinator.java

@@ -20,9 +20,7 @@
 package io.druid.indexing.worker;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.google.common.base.Function;
 import com.google.common.base.Joiner;
-import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.MoreExecutors;
@@ -37,9 +35,9 @@ import io.druid.indexing.overlord.config.RemoteTaskRunnerConfig;
 import io.druid.server.initialization.IndexerZkConfig;
 import org.apache.curator.framework.CuratorFramework;
 import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.KeeperException;
 import org.joda.time.DateTime;
 
-import javax.annotation.Nullable;
 import java.util.Arrays;
 import java.util.List;
 
@@ -167,24 +165,23 @@ public class WorkerCuratorCoordinator
     return worker;
   }
 
-  public void removeTaskRunZnode(String taskId)
+  public void removeTaskRunZnode(String taskId) throws Exception
   {
     try {
       curatorFramework.delete().guaranteed().forPath(getTaskPathForId(taskId));
     }
-    catch (Exception e) {
+    catch (KeeperException e) {
       log.warn(e, "Could not delete task path for task[%s]", taskId);
     }
   }
 
-  public void updateTaskStatusAnnouncement(TaskAnnouncement announcement)
+  public void updateTaskStatusAnnouncement(TaskAnnouncement announcement) throws Exception
   {
     synchronized (lock) {
       if (!started) {
         return;
       }
 
-      try {
       CuratorUtils.createOrSet(
           curatorFramework,
           getStatusPathForId(announcement.getTaskStatus().getId()),
@@ -193,38 +190,22 @@ public class WorkerCuratorCoordinator
           config.getMaxZnodeBytes()
       );
     }
-      catch (Exception e) {
-        throw Throwables.propagate(e);
-      }
-    }
   }
 
-  public List<TaskAnnouncement> getAnnouncements()
+  public List<TaskAnnouncement> getAnnouncements() throws Exception
   {
-    try {
-      return Lists.transform(
-          curatorFramework.getChildren().forPath(getStatusPathForWorker()), new Function<String, TaskAnnouncement>()
-          {
-            @Nullable
-            @Override
-            public TaskAnnouncement apply(String input)
-            {
-              try {
-                return jsonMapper.readValue(
-                    curatorFramework.getData().forPath(getStatusPathForId(input)),
+    final List<TaskAnnouncement> announcements = Lists.newArrayList();
+
+    for (String id : curatorFramework.getChildren().forPath(getStatusPathForWorker())) {
+      announcements.add(
+          jsonMapper.readValue(
+              curatorFramework.getData().forPath(getStatusPathForId(id)),
               TaskAnnouncement.class
+          )
       );
     }
-              catch (Exception e) {
-                throw Throwables.propagate(e);
-              }
-            }
-          }
-      );
-    }
-    catch (Exception e) {
-      throw Throwables.propagate(e);
-    }
+
+    return announcements;
   }
 
   public void updateWorkerAnnouncement(Worker newWorker) throws Exception

indexing-service/src/main/java/io/druid/indexing/worker/WorkerTaskMonitor.java

@@ -21,7 +21,6 @@ package io.druid.indexing.worker;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Preconditions;
-import com.google.common.base.Throwables;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -98,7 +97,7 @@ public class WorkerTaskMonitor
    * started the task. When the task is complete, the worker node updates the status.
    */
   @LifecycleStart
-  public void start()
+  public void start() throws Exception
   {
     synchronized (lifecycleLock) {
       Preconditions.checkState(!started, "already started");
@@ -125,10 +124,13 @@ public class WorkerTaskMonitor
         log.info("Started WorkerTaskMonitor.");
         started = true;
       }
+      catch (InterruptedException e) {
+        throw e;
+      }
       catch (Exception e) {
         log.makeAlert(e, "Exception starting WorkerTaskMonitor")
            .emit();
-        throw Throwables.propagate(e);
+        throw e;
       }
     }
   }
@@ -142,6 +144,10 @@ public class WorkerTaskMonitor
         try {
           notice.handle();
         }
+        catch (InterruptedException e) {
+          // Will be caught and logged in the outer try block
+          throw e;
+        }
         catch (Exception e) {
           log.makeAlert(e, "Failed to handle notice")
              .addData("noticeClass", notice.getClass().getSimpleName())
@@ -166,7 +172,7 @@ public class WorkerTaskMonitor
     }
   }
 
-  private void cleanupStaleAnnouncements()
+  private void cleanupStaleAnnouncements() throws Exception
   {
     // cleanup any old running task announcements which are invalid after restart
     for (TaskAnnouncement announcement : workerCuratorCoordinator.getAnnouncements()) {
@@ -292,7 +298,7 @@ public class WorkerTaskMonitor
   {
     String getTaskId();
 
-    void handle();
+    void handle() throws Exception;
   }
 
   private class RunNotice implements Notice
@@ -311,7 +317,7 @@ public class WorkerTaskMonitor
     }
 
     @Override
-    public void handle()
+    public void handle() throws Exception
     {
       if (running.containsKey(task.getId())) {
         log.warn(
@@ -357,7 +363,7 @@ public class WorkerTaskMonitor
     }
 
     @Override
-    public void handle()
+    public void handle() throws Exception
     {
       final TaskDetails details = running.get(task.getId());
 
@@ -391,6 +397,9 @@ public class WorkerTaskMonitor
             status.getStatusCode()
         );
       }
+      catch (InterruptedException e) {
+        throw e;
+      }
       catch (Exception e) {
         log.makeAlert(e, "Failed to update task announcement")
            .addData("task", task.getId())
@@ -420,7 +429,7 @@ public class WorkerTaskMonitor
     }
 
     @Override
-    public void handle()
+    public void handle() throws InterruptedException
     {
       final TaskDetails details = running.get(taskId);
 
@@ -442,6 +451,9 @@ public class WorkerTaskMonitor
               )
           );
         }
+        catch (InterruptedException e) {
+          throw e;
+        }
         catch (Exception e) {
           log.makeAlert(e, "Failed to update task announcement")
              .addData("task", taskId)