[
https://issues.apache.org/jira/browse/FLINK-9524?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16516155#comment-16516155
]
ASF GitHub Bot commented on FLINK-9524:
---------------------------------------
GitHub user yzandrew opened a pull request:
https://github.com/apache/flink/pull/6180
[FLINK-9524][Table API & SQL] check whether a clean-up timer is expeired in
ProcTimeBoundedRangeOver…
… to prevent NPE
## What is the purpose of the change
This pull request solve the bug that causes NPE in
ProcTimeBoundedRangeOver. Now the onTimer method will check whether the timer
is a expired clean-up timer.
## Brief change log
- ProcTimeBoundedRangeOver check whether the timer is a expired clean-up
timer. It's done by a null check against the elements within rowMapState. If
it's null, it means the timer is an expired clean-up timer and bypass the
remained logic.
## Verifying this change
This change is a trivial rework / code cleanup without any test coverage.
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): no
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: no
- The serializers: no
- The runtime per-record code paths (performance sensitive): no
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: no
- The S3 file system connector: no
## Documentation
- Does this pull request introduce a new feature? no
- If yes, how is the feature documented? not applicable
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/yzandrew/flink master
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/6180.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #6180
----
commit 719bdebf6bdb0e3e3f9aa0acd0bb98040a259a59
Author: yan.zhou <yzhou@...>
Date: 2018-06-18T18:42:29Z
[FLINK-9524] check whether a clean-up timer is expeired in
ProcTimeBoundedRangeOver to prevent NPE
----
> NPE from ProcTimeBoundedRangeOver.scala
> ---------------------------------------
>
> Key: FLINK-9524
> URL: https://issues.apache.org/jira/browse/FLINK-9524
> Project: Flink
> Issue Type: Bug
> Components: Table API & SQL
> Affects Versions: 1.5.0
> Reporter: yan zhou
> Assignee: yan zhou
> Priority: Major
> Attachments: npe_from_ProcTimeBoundedRangeOver.txt
>
>
> The class _ProcTimeBoundedRangeOver_ would throws NPE if _minRetentionTime_
> and _maxRetentionTime_ are set to greater then 1.
> Please see [^npe_from_ProcTimeBoundedRangeOver.txt] for the detail of
> exception. Below is a short description of the cause:
> * When the first event for a key arrives, the cleanup time is registered
> with _timerservice_ and recorded in _cleanupTimeState_. If the second event
> with same key arrives before the cleanup time, the value in
> _cleanupTimeState_ is updated and a new timer is registered to
> _timerService_. So now we have two registered timers for cleanup. One is
> registered because of the first event, the other for the second event.
> * However, when _onTimer_ method is fired for the first cleanup timer, the
> _cleanupTimeStates_ value has already been updated to second cleanup time. So
> it will bypass the _needToCleanupState_ check, and yet run through the
> remained code of _onTimer_ (which is intended to update the accumulator and
> emit output) and cause NPE.
> _RowTimeBoundedRangeOver_ has very similar logic with
> _ProcTimeBoundedRangeOver. But_ It won't cause NPE by the same reason. To
> avoid the exception, it simply add a null check before running the logic for
> updating accumulator.
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
