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Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

kafka-consumer-perf-test is a great tool to quickly check raw consumer performance. Currently, It subscribes to all the partitions and gives overall cluster performance, however If we want to test performance of single broker/partition, existing tool does not support. Single partition performance test is helpful in debugging and capacity/resource estimates.

For example, In one of the troubleshooting scenario on production we observed that our Spark Structured Streaming consumer was lagging because some of the tasks were taking longer. We observed that all tasks were reading from different partitions and amount of records to process were equal. However, fetch-time for some of the partitions were higher than the others. With modified kafka-consumer-perf-test we were able to confirm the same and we narrowed down problem to single broker having faulty switch. 

This modification allowed Hardware team to easily perform experiments and verify the resolutionDescribe the problems you are trying to solve.

Public Interfaces

Briefly list any new interfaces that will be introduced as part of this proposal or any existing interfaces that will be removed or changed. The purpose of this section is to concisely call out the public contract that will come along with this feature.

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