[HBASE-18441] ZookeeperWatcher#interruptedException should throw exception

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.4.0, 2.0.0, 1.2.7
• Component/s: Zookeeper
• Hadoop Flags: Reviewed
• Assignee: Yu Li
• Reporter: Yu Li
• Created: 24/Jul/17 04:58
• Updated: 07/Sep/18 01:59
• Resolved: 26/Jul/17 07:25

Description

Currently Zookeeper#interruptedException will swallow the InterruptedException and only log, which might cause unexpected behavior, such as when invoking ZKUtil#checkExists and the watcher thread somehow interrupted, the method will return -1 which means the checked znode doesn't exist, while actually the znode exists.

We could also see a TODO tag in the javadoc, which indicates we need some fix/improvement here:

  /**
   * Handles InterruptedExceptions in client calls.
   * <p>
   * This may be temporary but for now this gives one place to deal with these.
   * <p>
   * TODO: Currently, this method does nothing.
   *       Is this ever expected to happen?  Do we abort or can we let it run?
   *       Maybe this should be logged as WARN?  It shouldn't happen?
   * <p>
   * @param ie
   */

Here we propose to throw a KeeperException$SystemErrorException in ZookeeperWatcher#interruptedException, and will add a UT case to cover the interruption scenario.

Issue Links

• is related to: HBASE-19205 Backport HBASE-18441 ZookeeperWatcher#interruptedException should throw exception