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  1. Core Server
  2. SERVER-31446

_getNextSessionMods can get stuck in a write conflict retry loop

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.6.0-rc3
    • Component/s: Sharding
    • Labels:
      None
    • Backwards Compatibility:
      Fully Compatible
    • Operating System:
      ALL
    • Sprint:
      Sharding 2017-10-23, Sharding 2017-11-13
    • Linked BF Score:
      0

      Description

      1. Shard receives _getNextSessionMods command.
      2. Command tries to query oplog and hits a WriteConflictException
      3. QueryYield::yieldAllLocks is called, but it returns early because it's using DBDirectClient so it does not throw away the snapshot (Note: First global lock is taken by AutoGetActiveCloner).
      4. Query loop retries, but since it never resets the state during yield, it gets a WCE again, so step#2 is repeated.

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              • Created:
                Updated:
                Resolved: