HBASE-10142 TestLogRolling#testLogRollOnDatanodeDeath test failure

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1551806 13f79535-47bb-0310-9956-ffa450edef68

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/FSHLog.java

@@ -39,6 +39,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -123,7 +124,6 @@ class FSHLog implements HLog, Syncable {
   private final AtomicLong syncedTillHere = new AtomicLong(0);
   private long lastDeferredTxid;
   private final Path oldLogDir;
-  private volatile boolean logRollRunning;
 
   // all writes pending on AsyncWriter/AsyncSyncer thread with
   // txid <= failedTxid will fail by throwing asyncIOE
@@ -158,7 +158,7 @@ class FSHLog implements HLog, Syncable {
    * This lock makes sure only one log roll runs at the same time. Should not be taken while
    * any other lock is held. We don't just use synchronized because that results in bogus and
    * tedious findbugs warning when it thinks synchronized controls writer thread safety */
-  private final Object rollWriterLock = new Object();
+  private final ReentrantLock rollWriterLock = new ReentrantLock(true);
 
   /**
    * Map of encoded region names to their most recent sequence/edit id in their memstore.
@@ -506,7 +506,8 @@ class FSHLog implements HLog, Syncable {
   @Override
   public byte [][] rollWriter(boolean force)
       throws FailedLogCloseException, IOException {
-    synchronized (rollWriterLock) {
+    rollWriterLock.lock();
+    try {
       // Return if nothing to flush.
       if (!force && this.writer != null && this.numEntries.get() <= 0) {
         return null;
@@ -517,7 +518,6 @@ class FSHLog implements HLog, Syncable {
         return null;
       }
       try {
-        this.logRollRunning = true;
         if (!closeBarrier.beginOp()) {
           LOG.debug("HLog closing. Skipping rolling of writer");
           return regionsToFlush;
@@ -595,10 +595,11 @@ class FSHLog implements HLog, Syncable {
           regionsToFlush = findRegionsToForceFlush();
         }
       } finally {
-        this.logRollRunning = false;
         closeBarrier.endOp();
       }
       return regionsToFlush;
+    } finally {
+      rollWriterLock.unlock();
     }
   }
 
@@ -1226,10 +1227,15 @@ class FSHLog implements HLog, Syncable {
           asyncNotifier.setFlushedTxid(this.lastSyncedTxid);
 
           // 4. check and do logRoll if needed
-          if (!logRollRunning) {
-            checkLowReplication();
+          boolean logRollNeeded = false;
+          if (rollWriterLock.tryLock()) {
             try {
-              if (writer != null && writer.getLength() > logrollsize) {
+              logRollNeeded = checkLowReplication();
+            } finally {
+              rollWriterLock.unlock();
+            }            
+            try {
+              if (logRollNeeded || writer != null && writer.getLength() > logrollsize) {
                 requestLogRoll();
               }
             } catch (IOException e) {
@@ -1332,7 +1338,11 @@ class FSHLog implements HLog, Syncable {
   @Override
   public void postAppend(List<Entry> entries) {}
 
-  private void checkLowReplication() {
+  /*
+   * @return whether log roll should be requested
+   */
+  private boolean checkLowReplication() {
+    boolean logRollNeeded = false;
     // if the number of replicas in HDFS has fallen below the configured
     // value, then roll logs.
     try {
@@ -1345,7 +1355,7 @@ class FSHLog implements HLog, Syncable {
                 + numCurrentReplicas + " replicas but expecting no less than "
                 + this.minTolerableReplication + " replicas. "
                 + " Requesting close of hlog.");
-            requestLogRoll();
+            logRollNeeded = true;
             // If rollWriter is requested, increase consecutiveLogRolls. Once it
             // is larger than lowReplicationRollLimit, disable the
             // LowReplication-Roller
@@ -1364,7 +1374,7 @@ class FSHLog implements HLog, Syncable {
           // So we should not enable LowReplication-Roller. If numEntries
           // is lower than or equals 1, we consider it as a new writer.
           if (this.numEntries.get() <= 1) {
-            return;
+            return logRollNeeded;
           }
           // Once the live datanode number and the replicas return to normal,
           // enable the LowReplication-Roller.
@@ -1376,6 +1386,7 @@ class FSHLog implements HLog, Syncable {
       LOG.warn("Unable to invoke DFSOutputStream.getNumCurrentReplicas" + e +
           " still proceeding ahead...");
     }
+    return logRollNeeded;
   }
 
   /**

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestLogRolling.java

@@ -396,7 +396,7 @@ public class TestLogRolling  {
     // the configured value 2.
     assertTrue(dfsCluster.stopDataNode(pipeline[1].getName()) != null);
 
-    batchWriteAndWait(table, 3, false, 10000);
+    batchWriteAndWait(table, 3, false, 14000);
     assertTrue("LowReplication Roller should've been disabled, current replication="
             + ((FSHLog) log).getLogReplication(),
         !log.isLowReplicationRollEnabled());