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https://issues.apache.org/jira/browse/HIVE-15376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15755093#comment-15755093
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Eugene Koifman commented on HIVE-15376:
---------------------------------------
patch 8
why did you remove acquireLocksWithHeartbeatDelay()?
I seems that in the process you changed when heartbeat starts for RO query. In
particular it starts before the lock record is even created.
It also looks like you cancelling logic is never reached when there is no lock
due to " if (!atLeastOneLock) {"
can you explain your changes in TestDbTxnManager.testLockTimeout() - this
used to test lock expiration for locks outside of a txn (e.g. RO query). You
now added a txn so that it tests a txn timeout.
Case 4 you added in TestDbTxnManager.testHeartbeater(). Since it doesn't run
the reaper process, what doe it test?
> Improve heartbeater scheduling for transactions
> -----------------------------------------------
>
> Key: HIVE-15376
> URL: https://issues.apache.org/jira/browse/HIVE-15376
> Project: Hive
> Issue Type: Bug
> Components: Transactions
> Affects Versions: 2.2.0
> Reporter: Wei Zheng
> Assignee: Wei Zheng
> Attachments: HIVE-15376.1.patch, HIVE-15376.2.patch,
> HIVE-15376.3.patch, HIVE-15376.4.patch, HIVE-15376.5.patch,
> HIVE-15376.6.patch, HIVE-15376.7.patch, HIVE-15376.8.patch
>
>
> HIVE-12366 improved the heartbeater logic by bringing down the gap between
> the lock acquisition and first heartbeat, but that's not enough, there may
> still be some issue, e.g.
> Time A: a transaction is opened
> Time B: acquireLocks is called (blocking call), but it can take a long time
> to actually acquire the locks and return if the system is busy
> Time C: as acquireLocks returns, the first heartbeat is sent
> If hive.txn.timeout < C - A, then the transaction will be timed out and
> aborted, thus causing failure.
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