hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gunther Hagleitner (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-4470) HS2 should disable local query execution
Date Fri, 26 Jul 2013 18:59:51 GMT

    [ https://issues.apache.org/jira/browse/HIVE-4470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13721070#comment-13721070
] 

Gunther Hagleitner commented on HIVE-4470:
------------------------------------------

Admin flag sounds good to me too.

{quote}
By performance penalty, do you mean the increased latency because of MR job launching?
{quote}

It's much worse than that. There's no way right now to run the local stage of a map join anywhere
but on the "client" machine, which is the HS2 machine in this case. So, you could either disable
map joins altogether for HS2 through admin flag (which means really expensive shuffle joins
for everything), or do the work to be able to run the hash table gen in the cluster, which
makes this ticket really huge.


                
> HS2 should disable local query execution
> ----------------------------------------
>
>                 Key: HIVE-4470
>                 URL: https://issues.apache.org/jira/browse/HIVE-4470
>             Project: Hive
>          Issue Type: Bug
>          Components: HiveServer2
>            Reporter: Thejas M Nair
>
> Hive can run queries in local mode (instead of using a cluster), if the size is small.
This happens when "hive.exec.mode.local.auto" is set to true.
> This would affect the stability of the hive server2 node, if you have heavy query processing
happening on it. Bugs in udfs triggered by a bad record can potentially add very heavy load
making the server inaccessible. 
> By default, HS2 should set these parameters to disallow local execution or send and error
message if user tries to set these.

--
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