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  1. Kafka
  2. KAFKA-9501

Promote Standby tasks to active tasks without closing them

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: 2.6.0
    • Fix Version/s: 2.6.0
    • Component/s: streams
    • Labels:
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      Description

      The purpose of StandbyTasks in Kafka Streams is fast failover. However, atm we close StandbyTasks (and create a new active task) if they are promoted to active.

      While this works ok for persistent state stores, it renders hot standbys for in-memory state stores useless, because we drop the in-memory state when we close the StandbyTask and thus the new active tasks needs to reread the changelog topic to recreate the in-memory state.

      Hence, we should promote StandbyTasks to active tasks without closing them. This will not only fix the issue for in-memory stores, but will make rebalancing faster for persistent state stores, too, because closing and reopening RocksDB has significant overhead.

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              • Assignee:
                ableegoldman A. Sophie Blee-Goldman
                Reporter:
                mjsax Matthias J. Sax
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                • Created:
                  Updated:
                  Resolved: