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Apurva Mehta commented on KAFKA-5794: ------------------------------------- Bumping this to a future release, we will just add the message format version to the {{TopicMetadata}} returned in {{MetadatResponse}} for this release. This will be tracked separately. > Introduce new idempotence mode to gracefully deal with topics on the older > message format > ----------------------------------------------------------------------------------------- > > Key: KAFKA-5794 > URL: https://issues.apache.org/jira/browse/KAFKA-5794 > Project: Kafka > Issue Type: Sub-task > Affects Versions: 0.11.0.0 > Reporter: Apurva Mehta > Assignee: Apurva Mehta > > In the discussion of KIP-185: Make exactly once in order delivery per > partition the default producer setting, it was realized that we don't have > graceful handling when an idempotence-enabled producer is writing to a broker > with a message format older than v2 (ie. the 0.11.0 message format). > In particular, if we enable idempotence, any produce requests to topics with > an older message format will fail with an UnsupportedVersionException. Thus > if the idempotent producer was to be made the default, the out of the box > producer would fail to produce when used with clusters which haven't upgraded > the message format yet. > This is particularly problematic since the recommended upgrade path is to > upgrade broker code while keeping the message format at the older version, > then upgrade all clients, and only finally upgrade the message format on the > server. With the current behavior, the middle step is actually untenable if > we enable idempotence as the default. > More details available at: > https://cwiki.apache.org/confluence/display/KAFKA/Kafka+Exactly+Once+-+Dealing+with+older+message+formats+when+idempotence+is+enabled -- This message was sent by Atlassian JIRA (v6.4.14#64029)