[
https://issues.apache.org/jira/browse/HBASE-5549?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13440351#comment-13440351
]
Himanshu Vashishtha commented on HBASE-5549:
--------------------------------------------
@Stack: So, currently (in this patch also), we don't wait for the Expired
event, which is not correct.
In 6354, v2 patch also doesn't look for it.
I added this check (as mentioned earlier) but sometimes, the only event
received is synConnected, and not the Expired event. So, it waits on the
AtomicBoolean sessionClosed, to become true, which will happen only when the
watcher received the Expired event. Thinking today, it looks like we should
invoke the close method only *after* the monitorwatcher is properly
initialized. Hmmm, I will look at this today again.
> Master can fail if ZooKeeper session expires
> --------------------------------------------
>
> Key: HBASE-5549
> URL: https://issues.apache.org/jira/browse/HBASE-5549
> Project: HBase
> Issue Type: Bug
> Components: master, zookeeper
> Affects Versions: 0.96.0
> Environment: all
> Reporter: nkeywal
> Assignee: nkeywal
> Priority: Minor
> Fix For: 0.92.2, 0.96.0, 0.94.2
>
> Attachments: 5549_092.txt, 5549_094.txt, 5549.v10.patch,
> 5549.v11.patch, 5549.v6.patch, 5549.v7.patch, 5549.v8.patch, 5549.v9.patch,
> nochange.patch
>
>
> There is a retry mechanism in RecoverableZooKeeper, but when the session
> expires, the whole ZooKeeperWatcher is recreated, hence the retry mechanism
> does not work in this case. This is why a sleep is needed in
> TestZooKeeper#testMasterSessionExpired: we need to wait for ZooKeeperWatcher
> to be recreated before using the connection.
> This can happen in real life, it can happen when:
> - master & zookeeper starts
> - zookeeper connection is cut
> - master enters the retry loop
> - in the meantime the session expires
> - the network comes back, the session is recreated
> - the retries continues, but on the wrong object, hence fails.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
