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  1. Core Server
  2. SERVER-65299

Not reset RetryableWriteTransactionParticipantCatalog upon starting an internal transaction for non-retryable write

    • Type: Icon: Bug Bug
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 6.0.0-rc0
    • Affects Version/s: None
    • Component/s: None
    • Labels:
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    • Fully Compatible
    • ALL
    • Sharding NYC 2022-04-18

      Resetting the RetryableWriteTransactionParticipantCatalog upon starting an internal transaction for a non-retryable write leads to an invariant failure in the following case.

      Consider a sharded collection with two chunks: chunk0 and chunk1, which reside on shard0 and shard1, respectively.

      1. The client starts a retryableWrite=false session S and performs a write against chunk0 in a transaction T0 with txnNumber0.
      2. chunk0 is moved from shard0 to shard1. During the migration, shard1 writes a dead-end sentinel noop oplog entry for T0.
      3. chunk0 is moved from shard1 back to shard0.
      4. The client performs a write against chunk1 in the session S outside a transaction. The write needs to executed using a transaction so the router executes it in an internal transaction for non-retryable write T1. Upon starting T1, shard1 resets/invalidates the RetryableWriteTransactionParticipantCatalog for S.
      5. chunk0 is moved from shard0 to shard1 again. During the migration, shard1 hits this invariant when processing the dead-end sentinel noop oplog entry for T0. Note that beginOrContinue() does not fail on shard1 with InCompleteTransactionHistory because from the perspective of shard1, txnNumber0 has always corresponded to a retryable write because of the dead-end sentinel oplog entry it wrote in step 2.

            Assignee:
            cheahuychou.mao@mongodb.com Cheahuychou Mao
            Reporter:
            cheahuychou.mao@mongodb.com Cheahuychou Mao
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              Created:
              Updated:
              Resolved: