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A new tag, source, will be added to all metrics registered by MirrorSourceConnector. It will contain the source cluster alias. For example:
kafka.connect.mirror:type=MirrorSourceConnector,source=one,target=two,topic=newtopic,partition=0

The new tag will be added in the front of the list of tags so the tag order is the same as MirrorCheckpointConnector metrics.

Proposed Changes

Update MirrorSourceMetrics to have a new tag, source, and set it to the source cluster alias.

Compatibility, Deprecation, and Migration Plan

• What impact (if any) will there be on existing users?
• If we are changing behavior how will we phase out the older behavior?
• If we need special migration tools, describe them here.
• When will we remove the existing behavior?

Test Plan

Describe in few sentences how the KIP will be tested. We are mostly interested in system tests (since unit-tests are specific to implementation details). How will we know that the implementation works as expected? How will we know nothing broke?

Rejected Alternatives

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This may break queries in monitoring tools that serialize tags in metric names.

Test Plan

This will be tested using unit tests.

Rejected Alternatives

• Add the source tag at the end of the list of tags: Since this has similar compatibility implications than the proposed method, I favored having the same tag order in MirrorSourceConnector and MirrorCheckpointConnector.