Hi Ufuk Celebi , I would like to contribute this issue.

Jark Wu Thanks for helping out here. I assigned the issue to you.

GitHub user wuchong opened a pull request:

https://github.com/apache/flink/pull/2453

FLINK-4510 [checkpoint] Always create CheckpointCoordinator

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This pull request always create checkpoint coordinator even if checkpointing interval is not configured.

I use a flag to indicate disabled periodic checkpoint, Instead of using an interval of 0. Because the interval is checked everywhere, too scared to change it...

You can merge this pull request into a Git repository by running:

$ git pull https://github.com/wuchong/flink FLINK-4510-checkpoint

Alternatively you can review and apply these changes as the patch at:

https://github.com/apache/flink/pull/2453.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 #2453

commit 7ba16434e3d450e0e1e9a8176a1c575945400bcd
Author: Jark Wu <wuchong.wc@alibaba-inc.com>
Date: 2016-09-01T08:15:33Z

FLINK-4510 [checkpoint] Always create CheckpointCoordinator

Github user StephanEwen commented on the issue:

https://github.com/apache/flink/pull/2453

Thanks for looking into this.

I wonder if we can do this simpler, without changes to the CheckpointCoordinator.
The only thing that really needs to change is that without periodic checkpoints, the `startCheckpointScheduler()` method is not called, which means that the JobStatusListener that "CheckpointActivatorDeactivator" should not be created and started.

Github user wuchong commented on the issue:

https://github.com/apache/flink/pull/2453

Make sense. I will update this PR.

Github user wuchong commented on the issue:

https://github.com/apache/flink/pull/2453

Hi @StephanEwen , I have updated this PR according to your suggestion. In addition, I use an interval of `Long.MAX_VALUE` for disabled periodic checkpoint. In this way, we will not break interval sanity check and no changes will be attached to `CheckpointCoordinator` and `JobSnapshottingSettings`.

Github user StephanEwen commented on the issue:

https://github.com/apache/flink/pull/2453

Will have a look at this again soon.

Github user StefanRRichter commented on the issue:

https://github.com/apache/flink/pull/2453

Thanks for the nice contribution.

I see one minor detail that could cause problems. Even if we do not register the `CheckpointCoordinator` as `JobStatusListener`, it might still be possible that `triggerCheckpoint(long timestamp, CheckpointProperties props)` gets called. In this case it can happen that a periodic trigger is registered. You could introduce another check on the interval to make sure that no periodic trigger can be registered when the CheckpointCoordinator is disabled.

Besides that, the changes look good to me.

Github user wuchong commented on the issue:

https://github.com/apache/flink/pull/2453

Hi @StefanRRichter , I fixed the conflicts, and add interval check in `triggerCheckpoint`. Could you have a look again ?

Github user StefanRRichter commented on the issue:

https://github.com/apache/flink/pull/2453

Looks good to me now.

Github user uce commented on the issue:

https://github.com/apache/flink/pull/2453

Thanks for the contribution. I'm going to merge this with slight modifications. We don't need the introduced checks with the current master as there is a check whether periodic checkpoints are activated.

Fixed in 398bd9b (master).

Github user asfgit closed the pull request at:

https://github.com/apache/flink/pull/2453

Fixed in b420750 (release-1.1).