YARN-1665. Simplify the configuration of RM HA by having better default values. Contributed by Xuan Gong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1565517 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -139,6 +139,9 @@ Release 2.4.0 - UNRELEASED
     be available across RM failover by making using of a remote
     configuration-provider. (Xuan Gong via vinodkv)
 
+    YARN-1665. Simplify the configuration of RM HA by having better default
+    values. (Xuan Gong via vinodkv)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -373,11 +373,11 @@ public class YarnConfiguration extends Configuration {
 
   public static final String AUTO_FAILOVER_ENABLED =
       AUTO_FAILOVER_PREFIX + "enabled";
-  public static final boolean DEFAULT_AUTO_FAILOVER_ENABLED = false;
+  public static final boolean DEFAULT_AUTO_FAILOVER_ENABLED = true;
 
   public static final String AUTO_FAILOVER_EMBEDDED =
       AUTO_FAILOVER_PREFIX + "embedded";
-  public static final boolean DEFAULT_AUTO_FAILOVER_EMBEDDED = false;
+  public static final boolean DEFAULT_AUTO_FAILOVER_EMBEDDED = true;
 
   public static final String AUTO_FAILOVER_ZK_BASE_PATH =
       AUTO_FAILOVER_PREFIX + "zk-base-path";

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/TestRMFailover.java

@@ -172,8 +172,6 @@ public class TestRMFailover extends ClientBaseWithFixes {
   @Test
   public void testAutomaticFailover()
       throws YarnException, InterruptedException, IOException {
-    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, true);
-    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_EMBEDDED, true);
     conf.set(YarnConfiguration.RM_CLUSTER_ID, "yarn-test-cluster");
     conf.set(YarnConfiguration.RM_ZK_ADDRESS, hostPort);
     conf.setInt(YarnConfiguration.RM_ZK_TIMEOUT_MS, 2000);
@@ -193,6 +191,7 @@ public class TestRMFailover extends ClientBaseWithFixes {
   @Test
   public void testWebAppProxyInStandAloneMode() throws YarnException,
       InterruptedException, IOException {
+    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     WebAppProxyServer webAppProxyServer = new WebAppProxyServer();
     try {
       conf.set(YarnConfiguration.PROXY_ADDRESS, "0.0.0.0:9099");
@@ -227,6 +226,7 @@ public class TestRMFailover extends ClientBaseWithFixes {
   @Test
   public void testEmbeddedWebAppProxy() throws YarnException,
       InterruptedException, IOException {
+    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     cluster.init(conf);
     cluster.start();
     getAdminService(0).transitionToActive(req);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml

@@ -405,17 +405,20 @@
   </property>
 
   <property>
-    <description>Enable automatic failover.</description>
+    <description>Enable automatic failover.
+      By default, it is enabled only when HA is enabled</description>
     <name>yarn.resourcemanager.ha.automatic-failover.enabled</name>
-    <value>false</value>
+    <value>true</value>
   </property>
 
   <property>
-    <description>Enable embedded automatic failover. The embedded elector
+    <description>Enable embedded automatic failover.
-      relies on the RM state store to handle fencing, and is primarily intended
+      By default, it is enabled only when HA is enabled.
-      to be used in conjunction with ZKRMStateStore.</description>
+      The embedded elector relies on the RM state store to handle fencing,
+      and is primarily intended to be used in conjunction with ZKRMStateStore.
+    </description>
     <name>yarn.resourcemanager.ha.automatic-failover.embedded</name>
-    <value>false</value>
+    <value>true</value>
   </property>
 
   <property>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestRMHA.java

@@ -119,6 +119,7 @@ public class TestRMHA {
    */
   @Test (timeout = 30000)
   public void testStartAndTransitions() throws IOException {
+    configuration.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     Configuration conf = new YarnConfiguration(configuration);
     rm = new MockRM(conf);
     rm.init(conf);
@@ -178,7 +179,6 @@ public class TestRMHA {
         "automatic failover is enabled";
 
     Configuration conf = new YarnConfiguration(configuration);
-    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, true);
 
     rm = new MockRM(conf);
     rm.init(conf);
@@ -236,6 +236,7 @@ public class TestRMHA {
     String errorMessageForEventHandler =
         "Expect to get the same number of handlers";
     String errorMessageForService = "Expect to get the same number of services";
+    configuration.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     Configuration conf = new YarnConfiguration(configuration);
     rm = new MockRM(conf) {
       @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/recovery/TestZKRMStateStore.java

@@ -159,6 +159,7 @@ public class TestZKRMStateStore extends RMStateStoreTestBase {
         HAServiceProtocol.RequestSource.REQUEST_BY_USER);
 
     Configuration conf1 = createHARMConf("rm1,rm2", "rm1", 1234);
+    conf1.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     ResourceManager rm1 = new ResourceManager();
     rm1.init(conf1);
     rm1.start();
@@ -170,6 +171,7 @@ public class TestZKRMStateStore extends RMStateStoreTestBase {
         rm1.getRMContext().getRMAdminService().getServiceStatus().getState());
 
     Configuration conf2 = createHARMConf("rm1,rm2", "rm2", 5678);
+    conf2.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     ResourceManager rm2 = new ResourceManager();
     rm2.init(conf2);
     rm2.start();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-tests/src/test/java/org/apache/hadoop/yarn/server/TestMiniYARNClusterForHA.java

@@ -42,7 +42,7 @@ public class TestMiniYARNClusterForHA {
   @Before
   public void setup() throws IOException, InterruptedException {
     Configuration conf = new YarnConfiguration();
-
+    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
     cluster = new MiniYARNCluster(TestMiniYARNClusterForHA.class.getName(),
         2, 1, 1, 1);
     cluster.init(conf);