[ 
https://issues.apache.org/jira/browse/HIVE-13149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15308845#comment-15308845
 ] 

Ashutosh Chauhan commented on HIVE-13149:
-----------------------------------------

I think this is pretty useful improvement.  [~vgumashta] Shall we commit this 
on branch-2.1 as well ?

> Remove some unnecessary HMS connections from HS2 
> -------------------------------------------------
>
>                 Key: HIVE-13149
>                 URL: https://issues.apache.org/jira/browse/HIVE-13149
>             Project: Hive
>          Issue Type: Sub-task
>          Components: HiveServer2
>    Affects Versions: 2.0.0
>            Reporter: Aihua Xu
>            Assignee: Aihua Xu
>             Fix For: 2.2.0
>
>         Attachments: HIVE-13149.1.patch, HIVE-13149.2.patch, 
> HIVE-13149.3.patch, HIVE-13149.4.patch, HIVE-13149.5.patch, 
> HIVE-13149.6.patch, HIVE-13149.7.patch, HIVE-13149.8.patch
>
>
> In SessionState class, currently we will always try to get a HMS connection 
> in {{start(SessionState startSs, boolean isAsync, LogHelper console)}} 
> regardless of if the connection will be used later or not. 
> When SessionState is accessed by the tasks in TaskRunner.java, although most 
> of the tasks other than some like StatsTask, don't need to access HMS. 
> Currently a new HMS connection will be established for each Task thread. If 
> HiveServer2 is configured to run in parallel and the query involves many 
> tasks, then the connections are created but unused.
> {noformat}
>   @Override
>   public void run() {
>     runner = Thread.currentThread();
>     try {
>       OperationLog.setCurrentOperationLog(operationLog);
>       SessionState.start(ss);
>       runSequential();
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to