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  1. Kafka
  2. KAFKA-6681

Two instances of kafka consumer reading the same partition within a consumer group

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: 0.10.2.1
    • Fix Version/s: 0.11.0.0
    • Component/s: clients, consumer
    • Labels:
      None

      Description

      We have seen this issue with the Kafka consumer, the new library that got introduced in 0.9

      With this new client, the group management is done by kafka coordinator, which is one of the kafka broker.

      We are using Kafka broker 0.10.2.1 and consumer client version is also 0.10.2.1 

      The issue that we have faced is that, after rebalancing, some of the partitions gets consumed by 2 instances within a consumer group, leading to duplication of the entire partition data. Both the instances continue to read until the next rebalancing, or the restart of those clients. 

      It looks like that a particular consumer goes on fetching the data from a partition, but the broker is not able to identify this "stale" consumer instance. 

      We have hit this twice in production. Please look at it the earliest. 

        Attachments

        1. server-1.log
          68 kB
          Narayan Periwal
        2. server-2.log
          50 kB
          Narayan Periwal

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            • Assignee:
              Unassigned
              Reporter:
              nperiwal Narayan Periwal
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              • Created:
                Updated:
                Resolved: