HDFS-11446. TestMaintenanceState#testWithNNAndDNRestart fails intermittently. Contributed by Yiqun Lin.

Author: linyiqun

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestMaintenanceState.java

@@ -18,7 +18,6 @@
 package org.apache.hadoop.hdfs;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -30,12 +29,7 @@
 import java.util.List;
 import java.util.Map;
 
-import com.google.common.collect.Lists;
 import org.apache.hadoop.fs.FSDataOutputStream;
-import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
-import org.junit.Assert;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
@@ -48,8 +42,16 @@
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.Time;
+import org.junit.Assert;
 import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Supplier;
+import com.google.common.collect.Lists;
 
 /**
  * This class tests node maintenance.
@@ -125,8 +127,8 @@ public void testTakeNodeOutOfEnteringMaintenance() throws Exception {
 
     // When node is in ENTERING_MAINTENANCE state, it can still serve read
     // requests
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, null,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas, null,
+        nodeOutofService);
 
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
 
@@ -387,8 +389,8 @@ private void testExpectedReplication(int replicationFactor,
 
     // The block should be replicated to another datanode to meet
     // expected replication count.
-    assertNull(checkWithRetry(ns, fileSys, file, expectedReplicasInRead,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, expectedReplicasInRead,
+        nodeOutofService);
 
     cleanupFile(fileSys, file);
     teardown();
@@ -548,19 +550,19 @@ public void testTransitionToDecommission() throws IOException {
         client.datanodeReport(DatanodeReportType.LIVE).length);
 
     // test 1, verify the replica in IN_MAINTENANCE state isn't in LocatedBlock
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     takeNodeOutofService(0, nodeOutofService.getDatanodeUuid(), 0, null,
         AdminStates.DECOMMISSIONED);
 
     // test 2 after decommission has completed, the replication count is
     // replicas + 1 which includes the decommissioned node.
-    assertNull(checkWithRetry(ns, fileSys, file, replicas + 1, null));
+    checkWithRetry(ns, fileSys, file, replicas + 1, null);
 
     // test 3, put the node in service, replication count should restore.
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, null));
+    checkWithRetry(ns, fileSys, file, replicas, null);
 
     cleanupFile(fileSys, file);
   }
@@ -587,8 +589,8 @@ public void testTransitionFromDecommissioning() throws IOException {
     takeNodeOutofService(0, nodeOutofService.getDatanodeUuid(), Long.MAX_VALUE,
         null, AdminStates.IN_MAINTENANCE);
 
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     cleanupFile(fileSys, file);
   }
@@ -631,10 +633,10 @@ private void testDecommissionDifferentNodeAfterMaintenance(int repl)
     takeNodeOutofService(0, decommissionDNUuid, 0, null, maintenanceNodes,
         AdminStates.DECOMMISSIONED);
     // Out of the replicas returned, one is the decommissioned node.
-    assertNull(checkWithRetry(ns, fileSys, file, repl, maintenanceDN));
+    checkWithRetry(ns, fileSys, file, repl, maintenanceDN);
 
     putNodeInService(0, maintenanceDN);
-    assertNull(checkWithRetry(ns, fileSys, file, repl + 1, null));
+    checkWithRetry(ns, fileSys, file, repl + 1, null);
 
     cleanupFile(fileSys, file);
     teardown();
@@ -663,15 +665,15 @@ public void testMultipleNodesMaintenance() throws Exception {
         AdminStates.IN_MAINTENANCE);
 
     // Verify file replication matches maintenance state min replication
-    assertNull(checkWithRetry(ns, fileSys, file, 1, null, nodes[0]));
+    checkWithRetry(ns, fileSys, file, 1, null, nodes[0]);
 
     // Put the maintenance nodes back in service
     for (DatanodeInfo datanodeInfo : maintenanceDN) {
       putNodeInService(0, datanodeInfo);
     }
 
     // Verify file replication catching up to the old state
-    assertNull(checkWithRetry(ns, fileSys, file, repl, null));
+    checkWithRetry(ns, fileSys, file, repl, null);
 
     cleanupFile(fileSys, file);
   }
@@ -720,19 +722,19 @@ private void testChangeReplicationFactor(int oldFactor, int newFactor,
 
     // Verify that the nodeOutofService remains in blocksMap and
     // # of live replicas For read operation is expected.
-    assertNull(checkWithRetry(ns, fileSys, file, oldFactor - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, oldFactor - 1,
+        nodeOutofService);
 
     final DFSClient client = getDfsClient(0);
     client.setReplication(file.toString(), (short)newFactor);
 
     // Verify that the nodeOutofService remains in blocksMap and
     // # of live replicas for read operation.
-    assertNull(checkWithRetry(ns, fileSys, file, expectedLiveReplicas,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, expectedLiveReplicas,
+        nodeOutofService);
 
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
-    assertNull(checkWithRetry(ns, fileSys, file, newFactor, null));
+    checkWithRetry(ns, fileSys, file, newFactor, null);
 
     cleanupFile(fileSys, file);
     teardown();
@@ -765,8 +767,8 @@ public void testTakeDeadNodeOutOfMaintenance() throws Exception {
         getFirstBlockFirstReplicaUuid(fileSys, file), Long.MAX_VALUE, null,
         AdminStates.IN_MAINTENANCE);
 
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     final DFSClient client = getDfsClient(0);
     assertEquals("All datanodes must be alive", numDatanodes,
@@ -779,16 +781,16 @@ public void testTakeDeadNodeOutOfMaintenance() throws Exception {
         client.datanodeReport(DatanodeReportType.LIVE).length);
 
     // Dead maintenance node's blocks should remain in block map.
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     // When dead maintenance mode is transitioned to out of maintenance mode,
     // its blocks should be removed from block map.
     // This will then trigger replication to restore the live replicas back
     // to replication factor.
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, nodeOutofService,
-        null));
+    checkWithRetry(ns, fileSys, file, replicas, nodeOutofService,
+        null);
 
     cleanupFile(fileSys, file);
   }
@@ -821,8 +823,8 @@ public void testWithNNAndDNRestart() throws Exception {
         getFirstBlockFirstReplicaUuid(fileSys, file), Long.MAX_VALUE, null,
         AdminStates.IN_MAINTENANCE);
 
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     DFSClient client = getDfsClient(0);
     assertEquals("All datanodes must be alive", numDatanodes,
@@ -836,23 +838,23 @@ public void testWithNNAndDNRestart() throws Exception {
         client.datanodeReport(DatanodeReportType.LIVE).length);
 
     // Dead maintenance node's blocks should remain in block map.
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService);
 
     // restart nn, nn will restore 3 live replicas given it doesn't
     // know the maintenance node has the replica.
     getCluster().restartNameNode(0);
     ns = getCluster().getNamesystem(0);
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, null));
+    checkWithRetry(ns, fileSys, file, replicas, null);
 
     // restart dn, nn has 1 maintenance replica and 3 live replicas.
     getCluster().restartDataNode(dnProp, true);
     getCluster().waitActive();
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, nodeOutofService));
+    checkWithRetry(ns, fileSys, file, replicas, nodeOutofService);
 
     // Put the node in service, a redundant replica should be removed.
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, null));
+    checkWithRetry(ns, fileSys, file, replicas, null);
 
     cleanupFile(fileSys, file);
   }
@@ -878,12 +880,12 @@ public void testWriteAfterMaintenance() throws IOException {
     writeFile(fileSys, file, replicas, 2);
 
     // Verify nodeOutofService wasn't chosen for write operation.
-    assertNull(checkWithRetry(ns, fileSys, file, replicas - 1,
-        nodeOutofService, null));
+    checkWithRetry(ns, fileSys, file, replicas - 1,
+        nodeOutofService, null);
 
     // Put the node back to service, live replicas should be restored.
     putNodeInService(0, nodeOutofService.getDatanodeUuid());
-    assertNull(checkWithRetry(ns, fileSys, file, replicas, null));
+    checkWithRetry(ns, fileSys, file, replicas, null);
 
     cleanupFile(fileSys, file);
   }
@@ -934,12 +936,12 @@ public void testInvalidation() throws IOException {
     client.setReplication(file.toString(), (short) 1);
 
     // Verify the nodeOutofService remains in blocksMap.
-    assertNull(checkWithRetry(ns, fileSys, file, 1, nodeOutofService));
+    checkWithRetry(ns, fileSys, file, 1, nodeOutofService);
 
     // Restart NN and verify the nodeOutofService remains in blocksMap.
     getCluster().restartNameNode(0);
     ns = getCluster().getNamesystem(0);
-    assertNull(checkWithRetry(ns, fileSys, file, 1, nodeOutofService));
+    checkWithRetry(ns, fileSys, file, 1, nodeOutofService);
 
     cleanupFile(fileSys, file);
   }
@@ -1081,30 +1083,32 @@ static String checkFile(FSNamesystem ns, FileSystem fileSys,
     return null;
   }
 
-  static String checkWithRetry(FSNamesystem ns, FileSystem fileSys,
-      Path name, int repl, DatanodeInfo inMaintenanceNode)
-          throws IOException {
-    return checkWithRetry(ns, fileSys, name, repl, inMaintenanceNode,
+  static void checkWithRetry(FSNamesystem ns, FileSystem fileSys, Path name,
+      int repl, DatanodeInfo inMaintenanceNode) {
+    checkWithRetry(ns, fileSys, name, repl, inMaintenanceNode,
         inMaintenanceNode);
   }
 
-  static String checkWithRetry(FSNamesystem ns, FileSystem fileSys,
-      Path name, int repl, DatanodeInfo excludedNode,
-      DatanodeInfo underMaintenanceNode) throws IOException {
-    int tries = 0;
-    String output = null;
-    while (tries++ < 200) {
-      try {
-        Thread.sleep(100);
-        output = checkFile(ns, fileSys, name, repl, excludedNode,
-            underMaintenanceNode);
-        if (output == null) {
-          break;
+  static void checkWithRetry(final FSNamesystem ns, final FileSystem fileSys,
+      final Path name, final int repl, final DatanodeInfo excludedNode,
+      final DatanodeInfo underMaintenanceNode) {
+    try {
+      GenericTestUtils.waitFor(new Supplier<Boolean>() {
+
+        @Override
+        public Boolean get() {
+          String output = null;
+          try {
+            output = checkFile(ns, fileSys, name, repl, excludedNode,
+                underMaintenanceNode);
+          } catch (Exception ignored) {
+          }
+
+          return (output == null);
         }
-      } catch (InterruptedException ie) {
-      }
+      }, 100, 60000);
+    } catch (Exception ignored) {
     }
-    return output;
   }
 
   static private DatanodeInfo[] getFirstBlockReplicasDatanodeInfos(