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ASF GitHub Bot commented on FLINK-2292: --------------------------------------- Github user mxm commented on the pull request: https://github.com/apache/flink/pull/896#issuecomment-120302065 > Looks like this change breaks the YARN integration. The YARN WordCount no longer works. Should be working again now. > It would be good if the accumulator update interval was configurable. > Edit: Is that the same value as the heartbeats? Yes, that was a design rationale to keep the message count low. We could only send the accumulators in every Nth heartbeat and let it be configurable. > The is a potential modification conflict: Drawing a snapshot for serialization and registering a new accumulator can lead to a ConcurrentModificationException in the drawing of the snapshot. I conducted tests with concurrent insertions and deletions and found that only concurrent removals cause ConcurrentModificationExceptions. Removals are not allowed for accumulators. Anyways, we could switch to a synchronized or copy on write hash map. If we do I would opt for the latter. > The naming of the accumulators refers sometimes to "flink vs. user-defined", and sometimes to "internal vs. external". Can we make this consistent? I actually like the "flink vs. user-defined" naming better. Then let's stick to the "flink vs. user-defined" naming scheme. > I think the code would be simpler is the registry simply always had a created map for internal and external accumulators. Also, a "reporter" object would help. I agree that would be a nicer way of dealing with the API. > Report accumulators periodically while job is running > ----------------------------------------------------- > > Key: FLINK-2292 > URL: https://issues.apache.org/jira/browse/FLINK-2292 > Project: Flink > Issue Type: Sub-task > Components: JobManager, TaskManager > Reporter: Maximilian Michels > Assignee: Maximilian Michels > Fix For: 0.10 > > > Accumulators should be sent periodically, as part of the heartbeat that sends > metrics. This allows them to be updated in real time. -- This message was sent by Atlassian JIRA (v6.3.4#6332)