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https://issues.apache.org/jira/browse/HIVE-11317?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14700482#comment-14700482
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Lefty Leverenz commented on HIVE-11317:
---------------------------------------

Just curious:  Why do the TimeValidators for these new parameters have 
MILLISECONDS while their default values are in seconds?  Other parameters match 
the defaults to the TimeValidator unit.

{code}
+    HIVE_TIMEDOUT_TXN_REAPER_START("hive.timedout.txn.reaper.start", "100s",
+      new TimeValidator(TimeUnit.MILLISECONDS), "Time delay of 1st reaper run 
after metastore start"),
+    HIVE_TIMEDOUT_TXN_REAPER_INTERVAL("hive.timedout.txn.reaper.interval", 
"180s",
+      new TimeValidator(TimeUnit.MILLISECONDS), "Time interval describing how 
often the reaper runs"),
{code}


> ACID: Improve transaction Abort logic due to timeout
> ----------------------------------------------------
>
>                 Key: HIVE-11317
>                 URL: https://issues.apache.org/jira/browse/HIVE-11317
>             Project: Hive
>          Issue Type: Bug
>          Components: Metastore, Transactions
>    Affects Versions: 1.0.0
>            Reporter: Eugene Koifman
>            Assignee: Eugene Koifman
>              Labels: TODOC1.3, triage
>             Fix For: 1.3.0
>
>         Attachments: HIVE-11317.2.patch, HIVE-11317.3.patch, 
> HIVE-11317.4.patch, HIVE-11317.5.patch, HIVE-11317.6.patch, HIVE-11317.patch
>
>
> the logic to Abort transactions that have stopped heartbeating is in
> TxnHandler.timeOutTxns()
> This is only called when DbTxnManger.getValidTxns() is called.
> So if there is a lot of txns that need to be timed out and the there are not 
> SQL clients talking to the system, there is nothing to abort dead 
> transactions, and thus compaction can't clean them up so garbage accumulates 
> in the system.
> Also, streaming api doesn't call DbTxnManager at all.
> Need to move this logic into Initiator (or some other metastore side thread).
> Also, make sure it is broken up into multiple small(er) transactions against 
> metastore DB.
> Also more timeOutLocks() locks there as well.
> see about adding TXNS.COMMENT field which can be used for "Auto aborted due 
> to timeout" for example.
> The symptom of this is that the system keeps showing more and more Open 
> transactions that don't seem to ever go away (and have no locks associated 
> with them)



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