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The WebRuntimeMonitor will contain a MetricFetcher which queries the JobManager for all available TaskManagers, and then query each of them for a metric dump. Metrics are only fetched if they actually accessed via REST calls, with a minimum time period (10 seconds) between updates.
This will be done with a TimerTask inside the MetricFetcher, which also has the responsibility to merge the returned dumps.
The merged dump is The fetched metrics are merged and kept in a central location inside the MetricFetcher, available to different handlers.
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