HADOOP-10980. TestActiveStandbyElector fails occasionally in trunk. Contributed by Eric Badger

(cherry picked from commit c82745432a962c817a8a7db92bb830fb6af01e33)

Conflicts:

	hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -28,6 +28,9 @@ Release 2.7.4 - UNRELEASED
     HADOOP-11149. Increase the timeout of TestZKFailoverController.
     (Steve Loughran via wheat9)
 
+    HADOOP-10980. TestActiveStandbyElector fails occasionally in trunk
+    (Eric Badger via jlowe)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java

@@ -613,13 +613,13 @@ public class ActiveStandbyElector implements StatCallback, StringCallback {
 
   /**
    * Get a new zookeeper client instance. protected so that test class can
-   * inherit and pass in a mock object for zookeeper
+   * inherit and mock out the zookeeper instance
    * 
    * @return new zookeeper client instance
    * @throws IOException
    * @throws KeeperException zookeeper connectionloss exception
    */
-  protected synchronized ZooKeeper getNewZooKeeper() throws IOException,
+  protected synchronized ZooKeeper connectToZooKeeper() throws IOException,
       KeeperException {
     
     // Unfortunately, the ZooKeeper constructor connects to ZooKeeper and
@@ -628,7 +628,7 @@ public class ActiveStandbyElector implements StatCallback, StringCallback {
     // we construct the watcher first, and have it block any events it receives
     // before we can set its ZooKeeper reference.
     watcher = new WatcherWithClientRef();
-    ZooKeeper zk = new ZooKeeper(zkHostPort, zkSessionTimeout, watcher);
+    ZooKeeper zk = createZooKeeper();
     watcher.setZooKeeperRef(zk);
 
     // Wait for the asynchronous success/failure. This may throw an exception
@@ -641,6 +641,17 @@ public class ActiveStandbyElector implements StatCallback, StringCallback {
     return zk;
   }
 
+  /**
+   * Get a new zookeeper client instance. protected so that test class can
+   * inherit and pass in a mock object for zookeeper
+   *
+   * @return new zookeeper client instance
+   * @throws IOException
+   */
+  protected ZooKeeper createZooKeeper() throws IOException {
+    return new ZooKeeper(zkHostPort, zkSessionTimeout, watcher);
+  }
+
   private void fatalError(String errorMessage) {
     LOG.fatal(errorMessage);
     reset();
@@ -772,7 +783,7 @@ public class ActiveStandbyElector implements StatCallback, StringCallback {
       zkClient = null;
       watcher = null;
     }
-    zkClient = getNewZooKeeper();
+    zkClient = connectToZooKeeper();
     LOG.debug("Created new connection for " + this);
   }
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ha/TestActiveStandbyElector.java

@@ -66,7 +66,7 @@ public class TestActiveStandbyElector {
     }
 
     @Override
-    public ZooKeeper getNewZooKeeper() {
+    public ZooKeeper connectToZooKeeper() {
       ++count;
       return mockZK;
     }
@@ -749,7 +749,15 @@ public class TestActiveStandbyElector {
     try {
       new ActiveStandbyElector("127.0.0.1", 2000, ZK_PARENT_NAME,
           Ids.OPEN_ACL_UNSAFE, Collections.<ZKAuthInfo> emptyList(), mockApp,
-          CommonConfigurationKeys.HA_FC_ELECTOR_ZK_OP_RETRIES_DEFAULT);
+          CommonConfigurationKeys.HA_FC_ELECTOR_ZK_OP_RETRIES_DEFAULT) {
+
+          @Override
+          protected ZooKeeper createZooKeeper() throws IOException {
+            return Mockito.mock(ZooKeeper.class);
+          }
+      };
+
+
       Assert.fail("Did not throw zookeeper connection loss exceptions!");
     } catch (KeeperException ke) {
       GenericTestUtils.assertExceptionContains( "ConnectionLoss", ke);