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  1. Core Server
  2. SERVER-7186

Batched oplog application increases frequency of idempotency violations

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Blocker - P1
    • Resolution: Fixed
    • Affects Version/s: 2.2.0
    • Fix Version/s: 2.2.1, 2.3.0
    • Component/s: Replication, Storage
    • Labels:
    • Backwards Compatibility:
      Fully Compatible
    • Operating System:
      ALL

      Description

      In 2.0.x, oplog entries are applied one at a time on each secondary. Thus, on a restart after a shutdown, only a single op can be applied twice. In 2.2.0, ops are applied in batches, so on a restart, potentially all the ops in the last batch can be reapplied. There are certain sequences of ops that violate idempotency guarantees needed to insure proper replication. In 2.2.0, if we detect such a sequence, the secondary halts replication and shuts down, unable to come back online.

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              Assignee:
              alerner Alberto Lerner
              Reporter:
              ian.whalen Ian Whalen
              Participants:
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                Created:
                Updated:
                Resolved: