HBASE-7247 Assignment performances decreased by 50% because of regionserver.OpenRegionHandler#tickleOpening

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1465914 13f79535-47bb-0310-9956-ffa450edef68

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKAssign.java

@@ -585,15 +585,79 @@ public class ZKAssign {
    * @param zkw zk reference
    * @param region region to be transitioned to opening
    * @param serverName server transition happens on
+   * @param updateZNode write the znode. If false, we only check.
    * @return version of node after transition, -1 if unsuccessful transition
    * @throws KeeperException if unexpected zookeeper exception
    */
   public static int retransitionNodeOpening(ZooKeeperWatcher zkw,
-      HRegionInfo region, ServerName serverName, int expectedVersion)
+      HRegionInfo region, ServerName serverName, int expectedVersion, boolean updateZNode)
   throws KeeperException {
-    return transitionNode(zkw, region, serverName,
-        EventType.RS_ZK_REGION_OPENING,
-        EventType.RS_ZK_REGION_OPENING, expectedVersion);
+
+    String encoded = region.getEncodedName();
+    if(LOG.isDebugEnabled()) {
+      LOG.debug(zkw.prefix("Attempting to retransition the opening state of node " +
+          HRegionInfo.prettyPrint(encoded)));
+    }
+
+    String node = getNodeName(zkw, encoded);
+    zkw.sync(node);
+
+    // Read existing data of the node
+    Stat stat = new Stat();
+    byte [] existingBytes = ZKUtil.getDataNoWatch(zkw, node, stat);
+    if (existingBytes == null) {
+      // Node no longer exists.  Return -1. It means unsuccessful transition.
+      return -1;
+    }
+    RegionTransition rt = getRegionTransition(existingBytes);
+
+    // Verify it is the expected version
+    if (expectedVersion != -1 && stat.getVersion() != expectedVersion) {
+      LOG.warn(zkw.prefix("Attempt to retransition the opening state of the " +
+          "unassigned node for " + encoded + " failed, " +
+          "the node existed but was version " + stat.getVersion() +
+          " not the expected version " + expectedVersion));
+      return -1;
+    }
+
+    // Verify it is in expected state
+    EventType et = rt.getEventType();
+    if (!et.equals(EventType.RS_ZK_REGION_OPENING)) {
+      String existingServer = (rt.getServerName() == null)
+          ? "<unknown>" : rt.getServerName().toString();
+      LOG.warn(zkw.prefix("Attempt to retransition the opening state of the unassigned node for "
+          + encoded + " failed, the node existed but was in the state " + et +
+          " set by the server " + existingServer));
+      return -1;
+    }
+
+    // We don't have to write the new state: the check is complete.
+    if (!updateZNode){
+      return expectedVersion;
+    }
+
+    // Write new data, ensuring data has not changed since we last read it
+    try {
+      rt = RegionTransition.createRegionTransition(
+          EventType.RS_ZK_REGION_OPENING, region.getRegionName(), serverName, null);
+      if(!ZKUtil.setData(zkw, node, rt.toByteArray(), stat.getVersion())) {
+        LOG.warn(zkw.prefix("Attempt to retransition the opening state of the " +
+            "unassigned node for " + encoded + " failed, " +
+            "the node existed and was in the expected state but then when " +
+            "setting data we got a version mismatch"));
+        return -1;
+      }
+      if(LOG.isDebugEnabled()) {
+        LOG.debug(zkw.prefix("Successfully retransition the opening state of node " + encoded));
+      }
+      return stat.getVersion() + 1;
+    } catch (KeeperException.NoNodeException nne) {
+      LOG.warn(zkw.prefix("Attempt to retransition the opening state of the " +
+          "unassigned node for " + encoded + " failed, " +
+          "the node existed and was in the expected state but then when " +
+          "setting data it no longer existed"));
+      return -1;
+    }
   }
 
   /**
@@ -712,6 +776,7 @@ public class ZKAssign {
     return transitionNode(zkw, region, serverName, beginState, endState, expectedVersion, null);
   }
 
+
   public static int transitionNode(ZooKeeperWatcher zkw, HRegionInfo region,
       ServerName serverName, EventType beginState, EventType endState,
       int expectedVersion, final byte [] payload)

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/OpenRegionHandler.java

@@ -50,6 +50,9 @@ public class OpenRegionHandler extends EventHandler {
   private final HRegionInfo regionInfo;
   private final HTableDescriptor htd;
 
+  private boolean tomActivated;
+  private int assignmentTimeout;
+
   // We get version of our znode at start of open process and monitor it across
   // the total open. We'll fail the open if someone hijacks our znode; we can
   // tell this has happened if version is not as expected.
@@ -78,6 +81,10 @@ public class OpenRegionHandler extends EventHandler {
     this.regionInfo = regionInfo;
     this.htd = htd;
     this.versionOfOfflineNode = versionOfOfflineNode;
+    tomActivated = this.server.getConfiguration().
+        getBoolean("hbase.assignment.timeout.management", false);
+    assignmentTimeout = this.server.getConfiguration().
+        getInt("hbase.master.assignment.timeoutmonitor.period", 10000);
   }
 
   public HRegionInfo getRegionInfo() {
@@ -234,10 +241,6 @@ public class OpenRegionHandler extends EventHandler {
     PostOpenDeployTasksThread t = new PostOpenDeployTasksThread(r,
       this.server, this.rsServices, signaller);
     t.start();
-    boolean tomActivated = this.server.getConfiguration().
-        getBoolean("hbase.assignment.timeout.management", false);
-    int assignmentTimeout = this.server.getConfiguration().
-      getInt("hbase.master.assignment.timeoutmonitor.period", 10000);
     // Total timeout for meta edit.  If we fail adding the edit then close out
     // the region and let it be assigned elsewhere.
     long timeout = assignmentTimeout * 10;
@@ -250,14 +253,12 @@ public class OpenRegionHandler extends EventHandler {
     boolean tickleOpening = true;
     while (!signaller.get() && t.isAlive() && !this.server.isStopped() &&
         !this.rsServices.isStopping() && (endTime > now)) {
-      if (tomActivated) {
       long elapsed = now - lastUpdate;
       if (elapsed > period) {
         // Only tickle OPENING if postOpenDeployTasks is taking some time.
         lastUpdate = now;
         tickleOpening = tickleOpening("post_open_deploy");
       }
-      }
       synchronized (signaller) {
         try {
           signaller.wait(period);
@@ -294,7 +295,7 @@ public class OpenRegionHandler extends EventHandler {
    * Thread to run region post open tasks. Call {@link #getException()} after
    * the thread finishes to check for exceptions running
    * {@link RegionServerServices#postOpenDeployTasks(
-   * HRegion, org.apache.hadoop.hbase.catalog.CatalogTracker, boolean)}
+   * HRegion, org.apache.hadoop.hbase.catalog.CatalogTracker)}
    * .
    */
   static class PostOpenDeployTasksThread extends Thread {
@@ -532,7 +533,7 @@ public class OpenRegionHandler extends EventHandler {
     try {
       this.version =
         ZKAssign.retransitionNodeOpening(server.getZooKeeper(),
-          this.regionInfo, this.server.getServerName(), this.version);
+          this.regionInfo, this.server.getServerName(), this.version, tomActivated);
     } catch (KeeperException e) {
       server.abort("Exception refreshing OPENING; region=" + encodedName +
         ", context=" + context, e);