YARN-2054. Better defaults for YARN ZK configs for retries and retry-inteval when HA is enabled. (kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1598630 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -117,6 +117,9 @@ Release 2.5.0 - UNRELEASED
     YARN-596. Use scheduling policies throughout the queue hierarchy to decide
     which containers to preempt (Wei Yan via Sandy Ryza)
 
+    YARN-2054. Better defaults for YARN ZK configs for retries and retry-inteval 
+    when HA is enabled. (kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES 

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

@@ -324,11 +324,11 @@ public class YarnConfiguration extends Configuration {
   public static final String RM_ZK_ADDRESS = RM_ZK_PREFIX + "address";
 
   public static final String RM_ZK_NUM_RETRIES = RM_ZK_PREFIX + "num-retries";
-  public static final int DEFAULT_ZK_RM_NUM_RETRIES = 500;
+  public static final int DEFAULT_ZK_RM_NUM_RETRIES = 1000;
 
   public static final String RM_ZK_RETRY_INTERVAL_MS =
       RM_ZK_PREFIX + "retry-interval-ms";
-  public static final long DEFAULT_RM_ZK_RETRY_INTERVAL_MS = 2000;
+  public static final long DEFAULT_RM_ZK_RETRY_INTERVAL_MS = 1000;
 
   public static final String RM_ZK_TIMEOUT_MS = RM_ZK_PREFIX + "timeout-ms";
   public static final int DEFAULT_RM_ZK_TIMEOUT_MS = 10000;

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

@@ -309,14 +309,17 @@
   <property>
     <description>Number of times RM tries to connect to ZooKeeper.</description>
     <name>yarn.resourcemanager.zk-num-retries</name>
-    <value>500</value>
+    <value>1000</value>
   </property>
 
   <property>
     <description>Retry interval in milliseconds when connecting to ZooKeeper.
+      When HA is enabled, the value here is NOT used. It is generated
+      automatically from yarn.resourcemanager.zk-timeout-ms and
+      yarn.resourcemanager.zk-num-retries.
     </description>
     <name>yarn.resourcemanager.zk-retry-interval-ms</name>
-    <value>2000</value>
+    <value>1000</value>
   </property>
 
   <property>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/recovery/ZKRMStateStore.java

@@ -90,7 +90,9 @@ public class ZKRMStateStore extends RMStateStore {
 
   private String zkHostPort = null;
   private int zkSessionTimeout;
-  private long zkRetryInterval;
+
+  @VisibleForTesting
+  long zkRetryInterval;
   private List<ACL> zkAcl;
   private List<ZKUtil.ZKAuthInfo> zkAuths;
 
@@ -199,9 +201,14 @@ public class ZKRMStateStore extends RMStateStore {
     zkSessionTimeout =
         conf.getInt(YarnConfiguration.RM_ZK_TIMEOUT_MS,
             YarnConfiguration.DEFAULT_RM_ZK_TIMEOUT_MS);
+
+    if (HAUtil.isHAEnabled(conf)) {
+      zkRetryInterval = zkSessionTimeout / numRetries;
+    } else {
       zkRetryInterval =
           conf.getLong(YarnConfiguration.RM_ZK_RETRY_INTERVAL_MS,
               YarnConfiguration.DEFAULT_RM_ZK_RETRY_INTERVAL_MS);
+    }
 
     zkAcl = RMZKUtils.getZKAcls(conf);
     zkAuths = RMZKUtils.getZKAuths(conf);

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

@@ -41,6 +41,7 @@ import java.security.NoSuchAlgorithmException;
 import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -203,7 +204,7 @@ public class TestZKRMStateStoreZKClientConnections extends
       LOG.error(error, e);
       fail(error);
     }
-    Assert.assertEquals("newBytes", new String(ret));
+    assertEquals("newBytes", new String(ret));
   }
 
   @Test(timeout = 20000)
@@ -232,7 +233,7 @@ public class TestZKRMStateStoreZKClientConnections extends
 
     try {
       byte[] ret = store.getDataWithRetries(path, false);
-      Assert.assertEquals("bytes", new String(ret));
+      assertEquals("bytes", new String(ret));
     } catch (Exception e) {
       String error = "New session creation failed";
       LOG.error(error, e);
@@ -281,4 +282,24 @@ public class TestZKRMStateStoreZKClientConnections extends
 
     zkClientTester.getRMStateStore(conf);
   }
+
+  @Test
+  public void testZKRetryInterval() throws Exception {
+    TestZKClient zkClientTester = new TestZKClient();
+    YarnConfiguration conf = new YarnConfiguration();
+
+    ZKRMStateStore store =
+        (ZKRMStateStore) zkClientTester.getRMStateStore(conf);
+    assertEquals(YarnConfiguration.DEFAULT_RM_ZK_RETRY_INTERVAL_MS,
+        store.zkRetryInterval);
+    store.stop();
+
+    conf.setBoolean(YarnConfiguration.RM_HA_ENABLED, true);
+    store =
+        (ZKRMStateStore) zkClientTester.getRMStateStore(conf);
+    assertEquals(YarnConfiguration.DEFAULT_RM_ZK_TIMEOUT_MS /
+            YarnConfiguration.DEFAULT_ZK_RM_NUM_RETRIES,
+        store.zkRetryInterval);
+    store.stop();
+  }
 }