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It would be ideal if the log.dir layout could be restructured from {topic}_{partition} format to {{topicIdprefix}}/{topicId}_{partition}, e.g. "mytopic_1" → "24/24cc4332-f7de-45a3-b24e-33d61aa0d16c_1". Note the hierarchical directory structure using the first two characters of the topic ID to avoid having too many directories at the top level of the logdir. The exact formatting of the directory is not set in stone, but the idea is to replace topic names with topic IDs in the log directory. This is a significant change and will only be added upon a major release, most likely alongside KIP-500 changes that will also prevent downgrades.

Migration

Topic IDs will only be available to brokers with IBP version 2.8 or greater.

Upon a controller becoming active, the list of current topics is loaded from /brokers/topics/[topic]. When a topic without a topic ID is found, a UUID will be randomly generated and assigned the topic information at /brokers/topics/[topic] will be updated with the id filled and the schema version bumped to version 3.

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