[jira] [Commented] (HBASE-7242) Use Runtime.exit() instead of Runtime.halt() upon HLog Sync failures

["Kannan Muthukkaruppan (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-7242?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13506993#comment-13506993 ] 

Kannan Muthukkaruppan commented on HBASE-7242:
----------------------------------------------

Currently, don't the shutdown hooks also try to flush/close the regions before closing the ZK connection?
                
> Use Runtime.exit() instead of Runtime.halt() upon HLog Sync failures
> --------------------------------------------------------------------
>
>                 Key: HBASE-7242
>                 URL: https://issues.apache.org/jira/browse/HBASE-7242
>             Project: HBase
>          Issue Type: Brainstorming
>            Reporter: Amitanand Aiyer
>            Priority: Minor
>
> Hey Guys,
>   Should we use Runtime.exit() instead of Runtime.halt(), when we fail a Hlog sync. 
>  The key difference is that Runtime.exit() is going to invoke the shutdown hooks; while Runtime.halt() does not.
>  Why we might need this: 
>    We had a HDFS name node reboot today on one of our cells, and this caused multiple region servers to abort because they could not sync the Hlog.
>    However, since multiple RS died simultaneously, this seemed like a co-related failure to the master. The master waits for the
> Znode to expire; but, this could take up to few minutes after RS death (this setting is in place so that we can withstand rack switch reboots, lasting a couple of minutes, without region movement).
>   If the shutdown hooks are called, RS will close the ZK connection, causing a immediate Znode expiry. This might help cut down the unavailability as 
> Regions can begin to get assigned faster.
>  While, we do want to abort on Hlog failure, I do not think it would hurt giving the JVM a few seconds to shutdown gracefully. Please let me know
> If I am missing something.
> Thanks,
> -Amit

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira