hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "stack (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-8729) distributedLogReplay may hang during chained region server failure
Date Wed, 12 Jun 2013 05:11:22 GMT

    [ https://issues.apache.org/jira/browse/HBASE-8729?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13680947#comment-13680947
] 

stack commented on HBASE-8729:
------------------------------

bq. If we don't introduce the new log replay handler, setting N is tricky and its value has
to be big enough so that we won't end up in issue of the JIRA. 

Ok.  So SSHs do basic processing and then we queue up all log splitting in the new set of
executors.... SSH can move on to next server and queue up more log splitting but won't get
blocked.

+1 then.
                
> distributedLogReplay may hang during chained region server failure
> ------------------------------------------------------------------
>
>                 Key: HBASE-8729
>                 URL: https://issues.apache.org/jira/browse/HBASE-8729
>             Project: HBase
>          Issue Type: Bug
>          Components: MTTR
>            Reporter: Jeffrey Zhong
>            Assignee: Jeffrey Zhong
>             Fix For: 0.98.0, 0.95.2
>
>         Attachments: 8729-v2.patch, hbase-8729.patch, hbase-8729-v3.patch
>
>
> In a test, half cluster(in terms of region servers) was down and some log replay had
incurred chained RS failures(receiving RS of a log replay failed again). 
> Since by default, we only allow 3 concurrent SSH handlers(controlled by {code}this.executorService.startExecutorService(ExecutorType.MASTER_SERVER_OPERATIONS,conf.getInt("hbase.master.executor.serverops.threads",
3));{code}).
> If all 3 SSH handlers are doing logReplay(blocking call) and one of receiving RS fails
again then logReplay will hang because regions of the newly failed RS can't be re-assigned
to another live RS(no ssh handler will be processed due to max threads setting) and existing
log replay will keep routing replay traffic to the dead RS.
> The fix is to submit logReplay work into a separate type of executor queue in order not
to block SSH region assignment so that logReplay can route traffic to a live RS after retries
and move forward. 

--
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

Mime
View raw message