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https://issues.apache.org/jira/browse/BEAM-8962?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16997437#comment-16997437
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Maximilian Michels commented on BEAM-8962:
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I think it is worth to think about disabling the metrics accumulator by default
and only enable it via a {{--enable_metrics_accumulator}}. The reason is that
it provides very little value. The accumulator is used to aggregate the final
metrics values to write them to the configured Beam MetricSink. However, this
is only done on job completion which makes this feature useless for streaming
applications. Even for batch, you probably want to be able to see metrics
during job execution which the accumulator does not provide. I'm inclined to
remove the feature entirely.
> FlinkMetricContainer causes churn in the JobManager and lets the web frontend
> malfunction
> -----------------------------------------------------------------------------------------
>
> Key: BEAM-8962
> URL: https://issues.apache.org/jira/browse/BEAM-8962
> Project: Beam
> Issue Type: Bug
> Components: runner-flink
> Reporter: Maximilian Michels
> Assignee: Maximilian Michels
> Priority: Major
> Fix For: 2.19.0
>
> Time Spent: 1.5h
> Remaining Estimate: 0h
>
> The {{FlinkMetricContainer}} wraps the Beam metric container for reporting
> metrics, but also stores them as Flink accumulators. With high parallelism
> jobs with over a thousand tasks and many built-in Beam metrics for every Beam
> step, this can accumulate to over 100MB of serialized data which is stored in
> the JobManager's ExecutionGraph. This then fails to even sent over the wire,
> due to the akka.framesize limit (10MB by default), and manifests in {{500
> Internal Server Error}}s in the web frontend.
> We need to introduce an option to disable the reporting via accumulators. It
> is mostly useful for batch workloads where you can retrieve the final
> accumulator values at the end of the job. It adds a lot of memory and network
> overhead.
> Perhaps we could even turn off the accumulators for streaming jobs, or
> entirely and make them opt-in.
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