[ 
https://issues.apache.org/jira/browse/ZOOKEEPER-2774?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16009577#comment-16009577
 ] 

ASF GitHub Bot commented on ZOOKEEPER-2774:
-------------------------------------------

GitHub user JiangJiafu opened a pull request:

    https://github.com/apache/zookeeper/pull/253

    ZOOKEEPER-2774

    

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/JiangJiafu/zookeeper ZOOKEEPER-2774

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/zookeeper/pull/253.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #253
    
----
commit 3ac65ead39fad4f8d9f26365e1bc73f83889f11e
Author: Jiang Jiafu <[email protected]>
Date:   2017-05-13T03:41:52Z

    ZOOKEEPER-2774

----


> Ephemeral znode will not be removed when sesstion timeout, if the system time 
> of ZooKeeper node changes unexpectedly.
> ---------------------------------------------------------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-2774
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2774
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: server
>    Affects Versions: 3.4.8, 3.4.9, 3.4.10
>         Environment: Centos6.5
>            Reporter: JiangJiafu
>
> 1. Deploy a ZooKeeper cluster with one node.
> 2. Create a Ephemeral znode.
> 3. Change the system time of the ZooKeeper node to a earlier point.
> 4. Disconnect the client with the ZooKeeper server.
> Then the ephemeral znode will exist for a long time even when session timeout.
> I have read the ZooKeeper source code and I find the code int 
> SessionTrackerImpl.java,
> {code:title=SessionTrackerImpl.java|borderStyle=solid}
>     @Override
>     synchronized public void run() {
>         try {
>             while (running) {
>                 currentTime = System.currentTimeMillis();
>                 if (nextExpirationTime > currentTime) {
>                     this.wait(nextExpirationTime - currentTime);
>                     continue;
>                 }
>                 SessionSet set;
>                 set = sessionSets.remove(nextExpirationTime);
>                 if (set != null) {
>                     for (SessionImpl s : set.sessions) {
>                         setSessionClosing(s.sessionId);
>                         expirer.expire(s);
>                     }
>                 }
>                 nextExpirationTime += expirationInterval;
>             }
>         } catch (InterruptedException e) {
>             handleException(this.getName(), e);
>         }
>         LOG.info("SessionTrackerImpl exited loop!");
>     }
> {code}
> I think it may be better to use System.nanoTime(), not 
> System.currentTimeMillis, because the later can be changed manually or 
> automatically by a NTP client. 



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to