From 5a34fa670e7d458e53ae37dd86f82933ba152eb0 Mon Sep 17 00:00:00 2001
From: Jason Lowe <jlowe@apache.org>
Date: Wed, 3 Aug 2016 20:17:30 +0000
Subject: [PATCH] HADOOP-10980. TestActiveStandbyElector fails occasionally in
 trunk. Contributed by Eric Badger (cherry picked from commit
 c82745432a962c817a8a7db92bb830fb6af01e33)

---
 .../hadoop/ha/ActiveStandbyElector.java       | 19 +++++++++++++++----
 .../hadoop/ha/TestActiveStandbyElector.java   | 12 ++++++++++--
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java
index cb2e08143e3..9a90ccfdadb 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/ActiveStandbyElector.java
@@ -667,13 +667,13 @@ 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
@@ -682,7 +682,7 @@ 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
@@ -695,6 +695,17 @@ 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();
@@ -830,7 +841,7 @@ public class ActiveStandbyElector implements StatCallback, StringCallback {
       zkClient = null;
       watcher = null;
     }
-    zkClient = getNewZooKeeper();
+    zkClient = connectToZooKeeper();
     if (LOG.isDebugEnabled()) {
       LOG.debug("Created new connection for " + this);
     }
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ha/TestActiveStandbyElector.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ha/TestActiveStandbyElector.java
index 83a3a4f8c85..8c6f7a3300a 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ha/TestActiveStandbyElector.java
+++ b/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);