[ 
https://issues.apache.org/jira/browse/HIVE-17647?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16439988#comment-16439988
 ] 

Sergey Shelukhin commented on HIVE-17647:
-----------------------------------------

Rebased the patch. [~ekoifman] can you review?

> DDLTask.generateAddMmTasks(Table tbl) and other random code should not start 
> transactions
> -----------------------------------------------------------------------------------------
>
>                 Key: HIVE-17647
>                 URL: https://issues.apache.org/jira/browse/HIVE-17647
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Transactions
>            Reporter: Eugene Koifman
>            Assignee: Sergey Shelukhin
>            Priority: Major
>              Labels: mm-gap-2
>         Attachments: HIVE-17647.01.patch, HIVE-17647.02.patch, 
> HIVE-17647.patch
>
>
> This method (and other places) have 
> {noformat}
>       if (txnManager.isTxnOpen()) {
>         mmWriteId = txnManager.getCurrentTxnId();
>       } else {
>         mmWriteId = txnManager.openTxn(new Context(conf), conf.getUser());
>         txnManager.commitTxn();
>       }
> {noformat}
> this should throw if there is no open transaction.  It should never open one.
> In general the logic seems suspect.  Looks like the intent is to move all 
> existing files into a delta_x_x/ when a plain table is converted to MM table. 
>  This seems like something that needs to be done from under an Exclusive lock 
> to prevent concurrent Insert operations writing data under table/partition 
> root.  But this is too late to acquire locks which should be done from the 
> Driver.acquireLocks()  (or else have deadlock detector since acquiring them 
> here would bread all-or-nothing lock acquisition semantics currently required 
> w/o deadlock detector)



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to