[ 
https://issues.apache.org/jira/browse/HIVE-11485?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15093318#comment-15093318
 ] 

Amareshwari Sriramadasu commented on HIVE-11485:
------------------------------------------------

bq. Users may not have any idea of asyc execution, such as those of Hue. 
If some users are running only sync execution, that should be perfectly fine. 

bq. It's way easy to leave those operations behind, consuming HS2 and cluster 
resources.
My bad : I was under impression that all operations (except async executions) 
are closed immediately by Hive itself - seeing this - 
https://github.com/apache/hive/blob/master/service/src/java/org/apache/hive/service/cli/session/HiveSessionImpl.java#L443
 - close is happening only in case of exceptions. Then it is a problem if 
session close is not clearing operations.

bq. Not to mention that they don't even have a way to cancel unwanted running 
operations.
Not sure what do you mean by that. cancel operation api already exists. But, 
sync executions return only after operation finishes.

bq. Nothing prevents a user session from running days or as long as the 
operation takes.
Sure. whats the story from Hive if the client crashes ? 

bq. Async execution was introduced as a problematic feature. It was a mistake 
in my opinion.
I disagree here. For long running jobs, if the execute is returning only after 
it finishes, there is no way for clients to know the status or cancel the 
query. And if client crashes after launching the query, the query would launch 
MR job on cluster and finish to completion, but client wont be aware of it and 
there is no way to consume the result as well. [~xuefuz], Can you please share 
what is problematic in async execution feature, what problem do you see in the 
design? We should correct them if there are any problems.



> Session close should not close async SQL operations
> ---------------------------------------------------
>
>                 Key: HIVE-11485
>                 URL: https://issues.apache.org/jira/browse/HIVE-11485
>             Project: Hive
>          Issue Type: Improvement
>          Components: HiveServer2
>            Reporter: Amareshwari Sriramadasu
>            Assignee: Deepak Barr
>         Attachments: HIVE-11485.master.patch
>
>
> Right now, session close on HiveServer closes all operations. But, queries 
> running are actually available across sessions and they are not tied to a 
> session (expect the launch - which requires configuration and resources). And 
> it allows getting the status of the query across sessions.
> But session close of the session ( on which operation is launched) closes all 
> the operations as well. 
> So, we should avoid closing all operations upon closing a session.



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

Reply via email to