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https://issues.apache.org/jira/browse/HIVE-11402?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15368895#comment-15368895
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Thejas M Nair commented on HIVE-11402:
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Sorry about the delay in reviewing.
This will however not disallow query execution in parallel when the query
execution is done asynchronously (the default mode with our jdbc driver).
> HS2 - add an option to disallow parallel query execution within a single
> Session
> --------------------------------------------------------------------------------
>
> Key: HIVE-11402
> URL: https://issues.apache.org/jira/browse/HIVE-11402
> Project: Hive
> Issue Type: Bug
> Components: HiveServer2
> Reporter: Thejas M Nair
> Assignee: Sergey Shelukhin
> Attachments: HIVE-11402.01.patch, HIVE-11402.02.patch,
> HIVE-11402.patch
>
>
> HiveServer2 currently allows concurrent queries to be run in a single
> session. However, every HS2 session has an associated SessionState object,
> and the use of SessionState in many places assumes that only one thread is
> using it, ie it is not thread safe.
> There are many places where SesssionState thread safety needs to be
> addressed, and until then we should serialize all query execution for a
> single HS2 session. -This problem can become more visible with HIVE-4239 now
> allowing parallel query compilation.-
> Note that running queries in parallel for single session is not
> straightforward with jdbc, you need to spawn another thread as the
> Statement.execute calls are blocking. I believe ODBC has non blocking query
> execution API, and Hue is another well known application that shares sessions
> for all queries that a user runs.
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