[HBASE-10448] ZKUtil create and watch methods don't set watch in some cases

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.96.0, 0.96.1.1
• Fix Version/s: 0.98.0, 0.96.2, 0.99.0, 0.94.17
• Component/s: Zookeeper
• Hadoop Flags: Reviewed
• Assignee: Jerry He
• Reporter: Jerry He
• Created: 31/Jan/14 18:24
• Updated: 26/Feb/14 04:45
• Resolved: 01/Feb/14 23:05

Description

While using the ZKUtil methods during testing, I found that watch was not set when it should be set based on the methods and method comments:
createNodeIfNotExistsAndWatch
createEphemeralNodeAndWatch

For example, in createNodeIfNotExistsAndWatch():

 public static boolean createNodeIfNotExistsAndWatch(
      ZooKeeperWatcher zkw, String znode, byte [] data)
  throws KeeperException {
    try {
      zkw.getRecoverableZooKeeper().create(znode, data, createACL(zkw, znode),
          CreateMode.PERSISTENT);
    } catch (KeeperException.NodeExistsException nee) {
      try {
        zkw.getRecoverableZooKeeper().exists(znode, zkw);
      } catch (InterruptedException e) {
        zkw.interruptedException(e);
        return false;
      }
      return false;
    } catch (InterruptedException e) {
      zkw.interruptedException(e);
      return false;
    }
    return true;
  }

The watch is only set via exists() call when the node already exists.
Similarly in createEphemeralNodeAndWatch():

  public static boolean createEphemeralNodeAndWatch(ZooKeeperWatcher zkw,
      String znode, byte [] data)
  throws KeeperException {
    try {
      zkw.getRecoverableZooKeeper().create(znode, data, createACL(zkw, znode),
          CreateMode.EPHEMERAL);
    } catch (KeeperException.NodeExistsException nee) {
      if(!watchAndCheckExists(zkw, znode)) {
        // It did exist but now it doesn't, try again
        return createEphemeralNodeAndWatch(zkw, znode, data);
      }
      return false;
    } catch (InterruptedException e) {
      LOG.info("Interrupted", e);
      Thread.currentThread().interrupt();
    }
    return true;
  }

Issue Links

• duplicates: HBASE-8937 createEphemeralNodeAndWatch don't set watcher if the node is created successfully