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

Motivation

Currently to have metadata for Kafka topics we have to use external storage (e.g. a database) and we need to keep it in synch with Kafka.

A topic is deleted, how to delete its metadata? How to deal with topics created by KafkaStream or KafkaConnect or KafkaAdmin.

Making Kafka self-sufficient in this aspect sounds goodDescribe 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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• 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?

Rejected Alternatives

Use the topic name as a suite of concatenation of metadata a.b.c or key_val.key_val.

the Topic name is limited to 245 characters and less when replicated 245 - alias size If there are alternative ways of accomplishing the same thing, what were they? The purpose of this section is to motivate why the design is the way it is and not some other way.