Current state: Voting In Progress
Discussion thread: here
Vote thread: here
Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
The consumer group command, when used for describing a consumer group in the default or
--offsets mode, currently reports current offset, log end offset, and the lag for each topic partition the group has offset for. It would be useful to extend the tool to also report the beginning offset for each partition. They could help with determining where the group stands with respect to consuming from the partition, whether it is consuming OK or is falling behind, what percentage of messages are consumed, whether the partition is empty, etc. The beginning or earliest log offset is not something that can be derived from the provided info.
The consumer group tool will be updated for
--describe --offsets options by adding a
No protocol change is required as the log start offset is readily available (similar to how log end offset is retrieved). The output of the command for
--describe --offsets options will change from something like this:
to something like this:
Compatibility, Deprecation, and Migration Plan
Users who use the consumer group command (e.g. in custom tools) and somehow rely on parsing the output of the
--describe --offsets options of the command may have to adjust their clients to account for this new column.