HDFS-13099. RBF: Use the ZooKeeper as the default State Store. Contributed by Yiqun Lin.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -34,8 +34,8 @@ import org.apache.hadoop.hdfs.server.federation.metrics.FederationRPCPerformance
 import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
 import org.apache.hadoop.hdfs.server.federation.resolver.MembershipNamenodeResolver;
 import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
-import org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileImpl;
 import org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreSerializerPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreZooKeeperImpl;
 import org.apache.hadoop.http.HttpConfig;
 
 /** 
@@ -1275,7 +1275,7 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String FEDERATION_STORE_DRIVER_CLASS =
       FEDERATION_STORE_PREFIX + "driver.class";
   public static final Class<? extends StateStoreDriver>
-      FEDERATION_STORE_DRIVER_CLASS_DEFAULT = StateStoreFileImpl.class;
+      FEDERATION_STORE_DRIVER_CLASS_DEFAULT = StateStoreZooKeeperImpl.class;
 
   public static final String FEDERATION_STORE_CONNECTION_TEST_MS =
       FEDERATION_STORE_PREFIX + "connection.test";

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -5085,9 +5085,15 @@
 
   <property>
     <name>dfs.federation.router.store.driver.class</name>
-    <value>org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileImpl</value>
+    <value>org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreZooKeeperImpl</value>
     <description>
-      Class to implement the State Store. By default it uses the local disk.
+      Class to implement the State Store. There are three implementation classes currently
+      being supported:
+      org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileImpl,
+      org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileSystemImpl and
+      org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreZooKeeperImpl.
+      These implementation classes use the local file, filesystem and ZooKeeper as a backend respectively.
+      By default it uses the ZooKeeper as the default State Store.
     </description>
   </property>
 

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSRouterFederation.md

@@ -325,7 +325,7 @@ The connection to the State Store and the internal caching at the Router.
 |:---- |:---- |:---- |
 | dfs.federation.router.store.enable | `true` | If `true`, the Router connects to the State Store. |
 | dfs.federation.router.store.serializer | `StateStoreSerializerPBImpl` | Class to serialize State Store records. |
-| dfs.federation.router.store.driver.class | `StateStoreZKImpl` | Class to implement the State Store. |
+| dfs.federation.router.store.driver.class | `StateStoreZooKeeperImpl` | Class to implement the State Store. |
 | dfs.federation.router.store.connection.test | 60000 | How often to check for the connection to the State Store in milliseconds. |
 | dfs.federation.router.cache.ttl | 60000 | How often to refresh the State Store caches in milliseconds. |
 | dfs.federation.router.store.membership.expiration | 300000 | Expiration time in milliseconds for a membership record. |

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/RouterConfigBuilder.java

@@ -19,6 +19,8 @@ package org.apache.hadoop.hdfs.server.federation;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
 
 /**
  * Constructs a router configuration with individual features enabled/disabled.
@@ -119,6 +121,10 @@ public class RouterConfigBuilder {
   }
 
   public RouterConfigBuilder stateStore() {
+    // reset the State Store driver implementation class for testing
+    conf.setClass(DFSConfigKeys.FEDERATION_STORE_DRIVER_CLASS,
+        FederationStateStoreTestUtils.getTestDriverClass(),
+        StateStoreDriver.class);
     return this.stateStore(true);
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/store/FederationStateStoreTestUtils.java

@@ -39,6 +39,7 @@ import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamenodeServiceState;
 import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
 import org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileBaseImpl;
+import org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreFileImpl;
 import org.apache.hadoop.hdfs.server.federation.store.records.BaseRecord;
 import org.apache.hadoop.hdfs.server.federation.store.records.MembershipState;
 import org.apache.hadoop.hdfs.server.federation.store.records.MembershipStats;
@@ -50,17 +51,21 @@ import org.apache.hadoop.util.Time;
  */
 public final class FederationStateStoreTestUtils {
 
+  /** The State Store Driver implementation class for testing .*/
+  private static final Class<? extends StateStoreDriver>
+      FEDERATION_STORE_DRIVER_CLASS_FOR_TEST = StateStoreFileImpl.class;
+
   private FederationStateStoreTestUtils() {
     // Utility Class
   }
 
   /**
-   * Get the default State Store driver implementation.
+   * Get the State Store driver implementation for testing.
    *
-   * @return Class of the default State Store driver implementation.
+   * @return Class of the State Store driver implementation.
    */
-  public static Class<? extends StateStoreDriver> getDefaultDriver() {
-    return DFSConfigKeys.FEDERATION_STORE_DRIVER_CLASS_DEFAULT;
+  public static Class<? extends StateStoreDriver> getTestDriverClass() {
+    return FEDERATION_STORE_DRIVER_CLASS_FOR_TEST;
   }
 
   /**
@@ -69,7 +74,7 @@ public final class FederationStateStoreTestUtils {
    * @return State Store configuration.
    */
   public static Configuration getStateStoreConfiguration() {
-    Class<? extends StateStoreDriver> clazz = getDefaultDriver();
+    Class<? extends StateStoreDriver> clazz = getTestDriverClass();
     return getStateStoreConfiguration(clazz);
   }
 
@@ -146,7 +151,7 @@ public final class FederationStateStoreTestUtils {
    * @throws IOException
    */
   public static void deleteStateStore() throws IOException {
-    Class<? extends StateStoreDriver> driverClass = getDefaultDriver();
+    Class<? extends StateStoreDriver> driverClass = getTestDriverClass();
     deleteStateStore(driverClass);
   }