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1) kafka.coordinator.group:type=GroupMetadataManagergroup-metadata-manager-metrics,name=TimeToLoadgroup-load-time-max

Type: SampledStat.Max

Value: 0 or greater over time; maximum time, in milliseconds, it took to load offsets and group metadata from one __consumer_offsets partition in the last 3 hours30 seconds.

2) kafka.coordinator.group:type=group-metadata-manager-metrics,name=group-load-time-avg

Type: SampledStat.Avg

Value: 0 or greater over time; average time, in milliseconds, it took to load offsets and group metadata from one __consumer_offsets partition in the last 30 seconds.

Note: this average may look very low at times when a majority of the partitions are unused causing some load times to be 0 seconds.

3) kafka.coordinator.group:type=TransactionStateManagertransaction-state-manager-metrics,name=TimeToLoadtransaction-load-time-max

Type: SampledStat.Max

Value: 0 or greater over time; maximum time, in milliseconds, it took to load offsets and transaction state from one __consumer_offsets partition in the last 3 hours30 seconds.

4) kafka.coordinator.group:type=transaction-state-manager-metrics,name=transaction-load-time-avg

Type: SampledStat.Avg

Value: 0 or greater over time; average time, in milliseconds, it took to load offsets and transaction state from one __consumer_offsets partition in the last 30 seconds.

Note: this average may look very low at times when a majority of the partitions are unused causing some load times to be 0 seconds.

Proposed Changes

For each of the group metadata manager and transaction state manager, add a sensor that indicates the max and avg number of milliseconds it took to load the partition. This max is and average are computed from a running window based on the partitions that were loaded finished loading in the last 3 hours. Lengthening or shortening the 3 hour time window is up for discussion (default is 30sec)30 seconds. 

Compatibility, Deprecation, and Migration Plan

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