HDFS-3871. Change NameNodeProxies to use RetryUtils. Contributed by Arun C Murthy

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1379743 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -434,6 +434,9 @@ Branch-2 ( Unreleased changes )
     HDFS-3177. Update DFSClient and DataXceiver to handle different checkum
     types in file checksum computation.  (Kihwal Lee via szetszwo)
 
+    HDFS-3871. Change NameNodeProxies to use RetryUtils.  (Arun C Murthy
+    via szetszwo)
+
   OPTIMIZATIONS
 
     HDFS-2982. Startup performance suffers when there are many edit log

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

@@ -57,6 +57,7 @@ import org.apache.hadoop.io.retry.FailoverProxyProvider;
 import org.apache.hadoop.io.retry.RetryPolicies;
 import org.apache.hadoop.io.retry.RetryPolicy;
 import org.apache.hadoop.io.retry.RetryProxy;
+import org.apache.hadoop.io.retry.RetryUtils;
 import org.apache.hadoop.ipc.ProtobufRpcEngine;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.RemoteException;
@@ -68,7 +69,6 @@ import org.apache.hadoop.security.authorize.RefreshAuthorizationPolicyProtocol;
 import org.apache.hadoop.tools.GetUserMappingsProtocol;
 
 import com.google.common.base.Preconditions;
-import com.google.protobuf.ServiceException;
 
 /**
  * Create proxy objects to communicate with a remote NN. All remote access to an
@@ -243,106 +243,20 @@ public class NameNodeProxies {
     return new NamenodeProtocolTranslatorPB(proxy);
   }
   
-  /**
-   * Return the default retry policy used in RPC.
-   * 
-   * If dfs.client.retry.policy.enabled == false, use TRY_ONCE_THEN_FAIL.
-   * 
-   * Otherwise, first unwrap ServiceException if possible, and then 
-   * (1) use multipleLinearRandomRetry for
-   *     - SafeModeException, or
-   *     - IOException other than RemoteException, or
-   *     - ServiceException; and
-   * (2) use TRY_ONCE_THEN_FAIL for
-   *     - non-SafeMode RemoteException, or
-   *     - non-IOException.
-   *     
-   * Note that dfs.client.retry.max < 0 is not allowed.
-   */
-  public static RetryPolicy getDefaultRetryPolicy(Configuration conf) {
-    final RetryPolicy multipleLinearRandomRetry = getMultipleLinearRandomRetry(conf);
-    if (LOG.isDebugEnabled()) {
-      LOG.debug("multipleLinearRandomRetry = " + multipleLinearRandomRetry);
-    }
-    if (multipleLinearRandomRetry == null) {
-      //no retry
-      return RetryPolicies.TRY_ONCE_THEN_FAIL;
-    } else {
-      return new RetryPolicy() {
-        @Override
-        public RetryAction shouldRetry(Exception e, int retries, int failovers,
-            boolean isMethodIdempotent) throws Exception {
-          if (e instanceof ServiceException) {
-            //unwrap ServiceException
-            final Throwable cause = e.getCause();
-            if (cause != null && cause instanceof Exception) {
-              e = (Exception)cause;
-            }
-          }
-
-          //see (1) and (2) in the javadoc of this method.
-          final RetryPolicy p;
-          if (e instanceof RemoteException) {
-            final RemoteException re = (RemoteException)e;
-            p = SafeModeException.class.getName().equals(re.getClassName())?
-                multipleLinearRandomRetry: RetryPolicies.TRY_ONCE_THEN_FAIL;
-          } else if (e instanceof IOException || e instanceof ServiceException) {
-            p = multipleLinearRandomRetry;
-          } else { //non-IOException
-            p = RetryPolicies.TRY_ONCE_THEN_FAIL;
-          }
-
-          if (LOG.isDebugEnabled()) {
-            LOG.debug("RETRY " + retries + ") policy="
-                + p.getClass().getSimpleName() + ", exception=" + e);
-          }
-          LOG.info("RETRY " + retries + ") policy="
-              + p.getClass().getSimpleName() + ", exception=" + e);
-          return p.shouldRetry(e, retries, failovers, isMethodIdempotent);
-        }
-
-        @Override
-        public String toString() {
-          return "RetryPolicy[" + multipleLinearRandomRetry + ", "
-              + RetryPolicies.TRY_ONCE_THEN_FAIL.getClass().getSimpleName()
-              + "]";
-        }
-      };
-    }
-  }
-
-  /**
-   * Return the MultipleLinearRandomRetry policy specified in the conf,
-   * or null if the feature is disabled.
-   * If the policy is specified in the conf but the policy cannot be parsed,
-   * the default policy is returned.
-   * 
-   * Conf property: N pairs of sleep-time and number-of-retries
-   *   dfs.client.retry.policy = "s1,n1,s2,n2,..."
-   */
-  private static RetryPolicy getMultipleLinearRandomRetry(Configuration conf) {
-    final boolean enabled = conf.getBoolean(
-        DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_KEY,
-        DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_DEFAULT);
-    if (!enabled) {
-      return null;
-    }
-
-    final String policy = conf.get(
-        DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_KEY,
-        DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_DEFAULT);
-
-    final RetryPolicy r = RetryPolicies.MultipleLinearRandomRetry.parseCommaSeparatedString(policy);
-    return r != null? r: RetryPolicies.MultipleLinearRandomRetry.parseCommaSeparatedString(
-        DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_DEFAULT);
-  }
-
   private static ClientProtocol createNNProxyWithClientProtocol(
       InetSocketAddress address, Configuration conf, UserGroupInformation ugi,
       boolean withRetries) throws IOException {
     RPC.setProtocolEngine(conf, ClientNamenodeProtocolPB.class, ProtobufRpcEngine.class);
 
-    final RetryPolicy defaultPolicy = getDefaultRetryPolicy(conf);
+    final RetryPolicy defaultPolicy = 
+        RetryUtils.getDefaultRetryPolicy(
+            conf, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_KEY, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_DEFAULT, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_KEY,
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_DEFAULT,
+            SafeModeException.class);
+    
     final long version = RPC.getProtocolVersion(ClientNamenodeProtocolPB.class);
     ClientNamenodeProtocolPB proxy = RPC.getProtocolProxy(
         ClientNamenodeProtocolPB.class, version, address, ugi, conf,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -54,7 +54,6 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.ByteRangeInputStream;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
-import org.apache.hadoop.hdfs.NameNodeProxies;
 import org.apache.hadoop.hdfs.protocol.DSQuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.NSQuotaExceededException;
@@ -89,6 +88,7 @@ import org.apache.hadoop.hdfs.web.resources.TokenArgumentParam;
 import org.apache.hadoop.hdfs.web.resources.UserParam;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.retry.RetryPolicy;
+import org.apache.hadoop.io.retry.RetryUtils;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.security.AccessControlException;
@@ -181,7 +181,14 @@ public class WebHdfsFileSystem extends FileSystem
       throw new IllegalArgumentException(e);
     }
     this.nnAddr = NetUtils.createSocketAddr(uri.getAuthority(), getDefaultPort());
-    this.retryPolicy = NameNodeProxies.getDefaultRetryPolicy(conf);
+    this.retryPolicy = 
+        RetryUtils.getDefaultRetryPolicy(
+            conf, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_KEY, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_ENABLED_DEFAULT, 
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_KEY,
+            DFSConfigKeys.DFS_CLIENT_RETRY_POLICY_SPEC_DEFAULT,
+            SafeModeException.class);
     this.workingDir = getHomeDirectory();
 
     if (UserGroupInformation.isSecurityEnabled()) {