HDFS-5399. Revisit SafeModeException and corresponding retry policies. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1564629 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/retry/RetryPolicies.java

@@ -151,6 +151,13 @@ public static final RetryPolicy failoverOnNetworkException(
         delayMillis, maxDelayBase);
   }
   
+  public static final RetryPolicy failoverOnNetworkException(
+      RetryPolicy fallbackPolicy, int maxFailovers, int maxRetries,
+      long delayMillis, long maxDelayBase) {
+    return new FailoverOnNetworkExceptionRetry(fallbackPolicy, maxFailovers,
+        maxRetries, delayMillis, maxDelayBase);
+  }
+  
   static class TryOnceThenFail implements RetryPolicy {
     @Override
     public RetryAction shouldRetry(Exception e, int retries, int failovers,
@@ -516,18 +523,25 @@ static class FailoverOnNetworkExceptionRetry implements RetryPolicy {
     
     private RetryPolicy fallbackPolicy;
     private int maxFailovers;
+    private int maxRetries;
     private long delayMillis;
     private long maxDelayBase;
     
     public FailoverOnNetworkExceptionRetry(RetryPolicy fallbackPolicy,
         int maxFailovers) {
-      this(fallbackPolicy, maxFailovers, 0, 0);
+      this(fallbackPolicy, maxFailovers, 0, 0, 0);
     }
     
     public FailoverOnNetworkExceptionRetry(RetryPolicy fallbackPolicy,
         int maxFailovers, long delayMillis, long maxDelayBase) {
+      this(fallbackPolicy, maxFailovers, 0, delayMillis, maxDelayBase);
+    }
+    
+    public FailoverOnNetworkExceptionRetry(RetryPolicy fallbackPolicy,
+        int maxFailovers, int maxRetries, long delayMillis, long maxDelayBase) {
       this.fallbackPolicy = fallbackPolicy;
       this.maxFailovers = maxFailovers;
+      this.maxRetries = maxRetries;
       this.delayMillis = delayMillis;
       this.maxDelayBase = maxDelayBase;
     }
@@ -549,6 +563,10 @@ public RetryAction shouldRetry(Exception e, int retries,
             "failovers (" + failovers + ") exceeded maximum allowed ("
             + maxFailovers + ")");
       }
+      if (retries - failovers > maxRetries) {
+        return new RetryAction(RetryAction.RetryDecision.FAIL, 0, "retries ("
+            + retries + ") exceeded maximum allowed (" + maxRetries + ")");
+      }
       
       if (e instanceof ConnectException ||
           e instanceof NoRouteToHostException ||

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

@@ -863,6 +863,9 @@ Release 2.3.0 - UNRELEASED
     HDFS-5842. Cannot create hftp filesystem when using a proxy user ugi and a doAs 
     on a secure cluster. (jing9)
 
+    HDFS-5399. Revisit SafeModeException and corresponding retry policies.
+    (Haohui Mai via todd)
+
   BREAKDOWN OF HDFS-2832 SUBTASKS AND RELATED JIRAS
 
     HDFS-4985. Add storage type to the protocol and expose it in block report

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

@@ -36,6 +36,8 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_BASE_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_MAX_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_MAX_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_RETRY_MAX_ATTEMPTS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_READ_PREFETCH_SIZE_KEY;
@@ -258,6 +260,7 @@ synchronized void unref(ClientMmapManager mmapManager) {
   public static class Conf {
     final int hdfsTimeout;    // timeout value for a DFS operation.
     final int maxFailoverAttempts;
+    final int maxRetryAttempts;
     final int failoverSleepBaseMillis;
     final int failoverSleepMaxMillis;
     final int maxBlockAcquireFailures;
@@ -303,6 +306,9 @@ public Conf(Configuration conf) {
       maxFailoverAttempts = conf.getInt(
           DFS_CLIENT_FAILOVER_MAX_ATTEMPTS_KEY,
           DFS_CLIENT_FAILOVER_MAX_ATTEMPTS_DEFAULT);
+      maxRetryAttempts = conf.getInt(
+          DFS_CLIENT_RETRY_MAX_ATTEMPTS_KEY,
+          DFS_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT);
       failoverSleepBaseMillis = conf.getInt(
           DFS_CLIENT_FAILOVER_SLEEPTIME_BASE_KEY,
           DFS_CLIENT_FAILOVER_SLEEPTIME_BASE_DEFAULT);

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

@@ -82,6 +82,8 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final int     DFS_CLIENT_FAILOVER_CONNECTION_RETRIES_DEFAULT = 0;
   public static final String  DFS_CLIENT_FAILOVER_CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_KEY = "dfs.client.failover.connection.retries.on.timeouts";
   public static final int     DFS_CLIENT_FAILOVER_CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_DEFAULT = 0;
+  public static final String  DFS_CLIENT_RETRY_MAX_ATTEMPTS_KEY = "dfs.client.retry.max.attempts";
+  public static final int     DFS_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT = 10;
   
   public static final String  DFS_CLIENT_SOCKET_CACHE_EXPIRY_MSEC_KEY = "dfs.client.socketcache.expiryMsec";
   public static final long    DFS_CLIENT_SOCKET_CACHE_EXPIRY_MSEC_DEFAULT = 2 * 60 * 1000;
@@ -574,6 +576,8 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String  DFS_HTTP_CLIENT_RETRY_POLICY_SPEC_DEFAULT = "10000,6,60000,10"; //t1,n1,t2,n2,...
   public static final String  DFS_HTTP_CLIENT_FAILOVER_MAX_ATTEMPTS_KEY = "dfs.http.client.failover.max.attempts";
   public static final int     DFS_HTTP_CLIENT_FAILOVER_MAX_ATTEMPTS_DEFAULT = 15;
+  public static final String  DFS_HTTP_CLIENT_RETRY_MAX_ATTEMPTS_KEY = "dfs.http.client.retry.max.attempts";
+  public static final int     DFS_HTTP_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT = 10;
   public static final String  DFS_HTTP_CLIENT_FAILOVER_SLEEPTIME_BASE_KEY = "dfs.http.client.failover.sleep.base.millis";
   public static final int     DFS_HTTP_CLIENT_FAILOVER_SLEEPTIME_BASE_DEFAULT = 500;
   public static final String  DFS_HTTP_CLIENT_FAILOVER_SLEEPTIME_MAX_KEY = "dfs.http.client.failover.sleep.max.millis";

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

@@ -24,6 +24,8 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_BASE_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_MAX_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_FAILOVER_SLEEPTIME_MAX_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_RETRY_MAX_ATTEMPTS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT;
 
 import java.io.IOException;
 import java.lang.reflect.Constructor;
@@ -144,9 +146,10 @@ public static <T> ProxyAndInfo<T> createProxy(Configuration conf,
           .createFailoverProxyProvider(conf, failoverProxyProviderClass, xface,
               nameNodeUri);
       Conf config = new Conf(conf);
-      T proxy = (T) RetryProxy.create(xface, failoverProxyProvider, RetryPolicies
+      T proxy = (T) RetryProxy.create(xface, failoverProxyProvider,
-          .failoverOnNetworkException(RetryPolicies.TRY_ONCE_THEN_FAIL,
+          RetryPolicies.failoverOnNetworkException(
-              config.maxFailoverAttempts, config.failoverSleepBaseMillis,
+              RetryPolicies.TRY_ONCE_THEN_FAIL, config.maxFailoverAttempts,
+              config.maxRetryAttempts, config.failoverSleepBaseMillis,
               config.failoverSleepMaxMillis));
       
       Text dtService = HAUtil.buildTokenServiceForLogicalUri(nameNodeUri);
@@ -192,11 +195,14 @@ public static <T> ProxyAndInfo<T> createProxyWithLossyRetryHandler(
       int maxFailoverAttempts = config.getInt(
           DFS_CLIENT_FAILOVER_MAX_ATTEMPTS_KEY,
           DFS_CLIENT_FAILOVER_MAX_ATTEMPTS_DEFAULT);
+      int maxRetryAttempts = config.getInt(
+          DFS_CLIENT_RETRY_MAX_ATTEMPTS_KEY,
+          DFS_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT);
       InvocationHandler dummyHandler = new LossyRetryInvocationHandler<T>(
               numResponseToDrop, failoverProxyProvider,
               RetryPolicies.failoverOnNetworkException(
-                  RetryPolicies.TRY_ONCE_THEN_FAIL, 
+                  RetryPolicies.TRY_ONCE_THEN_FAIL, maxFailoverAttempts, 
-                  Math.max(numResponseToDrop + 1, maxFailoverAttempts), delay, 
+                  Math.max(numResponseToDrop + 1, maxRetryAttempts), delay, 
                   maxCap));
       
       T proxy = (T) Proxy.newProxyInstance(

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -1161,7 +1161,8 @@ private void checkNameNodeSafeMode(String errorMsg)
     if (isInSafeMode()) {
       SafeModeException se = new SafeModeException(errorMsg, safeMode);
       if (haEnabled && haContext != null
-          && haContext.getState().getServiceState() == HAServiceState.ACTIVE) {
+          && haContext.getState().getServiceState() == HAServiceState.ACTIVE
+          && shouldRetrySafeMode(this.safeMode)) {
         throw new RetriableException(se);
       } else {
         throw se;
@@ -1169,6 +1170,18 @@ private void checkNameNodeSafeMode(String errorMsg)
     }
   }
   
+  /**
+   * We already know that the safemode is on. We will throw a RetriableException
+   * if the safemode is not manual or caused by low resource.
+   */
+  private boolean shouldRetrySafeMode(SafeModeInfo safeMode) {
+    if (safeMode == null) {
+      return false;
+    } else {
+      return !safeMode.isManual() && !safeMode.areResourcesLow();
+    }
+  }
+  
   public static Collection<URI> getNamespaceDirs(Configuration conf) {
     return getStorageDirs(conf, DFS_NAMENODE_NAME_DIR_KEY);
   }

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

@@ -188,6 +188,9 @@ public synchronized void initialize(URI uri, Configuration conf
       int maxFailoverAttempts = conf.getInt(
           DFSConfigKeys.DFS_HTTP_CLIENT_FAILOVER_MAX_ATTEMPTS_KEY,
           DFSConfigKeys.DFS_HTTP_CLIENT_FAILOVER_MAX_ATTEMPTS_DEFAULT);
+      int maxRetryAttempts = conf.getInt(
+          DFSConfigKeys.DFS_HTTP_CLIENT_RETRY_MAX_ATTEMPTS_KEY,
+          DFSConfigKeys.DFS_HTTP_CLIENT_RETRY_MAX_ATTEMPTS_DEFAULT);
       int failoverSleepBaseMillis = conf.getInt(
           DFSConfigKeys.DFS_HTTP_CLIENT_FAILOVER_SLEEPTIME_BASE_KEY,
           DFSConfigKeys.DFS_HTTP_CLIENT_FAILOVER_SLEEPTIME_BASE_DEFAULT);
@@ -197,7 +200,7 @@ public synchronized void initialize(URI uri, Configuration conf
 
       this.retryPolicy = RetryPolicies
           .failoverOnNetworkException(RetryPolicies.TRY_ONCE_THEN_FAIL,
-              maxFailoverAttempts, failoverSleepBaseMillis,
+              maxFailoverAttempts, maxRetryAttempts, failoverSleepBaseMillis,
               failoverSleepMaxMillis);
     }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestHASafeMode.java

@@ -55,6 +55,7 @@
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.namenode.FSImage;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystem.SafeModeInfo;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.apache.hadoop.io.IOUtils;
@@ -65,6 +66,7 @@
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.mockito.internal.util.reflection.Whitebox;
 
 import com.google.common.base.Supplier;
 import com.google.common.collect.Lists;
@@ -124,6 +126,9 @@ public void testClientRetrySafeMode() throws Exception {
     final Path test = new Path("/test");
     // let nn0 enter safemode
     NameNodeAdapter.enterSafeMode(nn0, false);
+    SafeModeInfo safeMode = (SafeModeInfo) Whitebox.getInternalState(
+        nn0.getNamesystem(), "safeMode");
+    Whitebox.setInternalState(safeMode, "extension", Integer.valueOf(30000));
     LOG.info("enter safemode");
     new Thread() {
       @Override