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