Uploaded image for project: 'Core Server'
  1. Core Server
  2. SERVER-7186

Batched oplog application increases frequency of idempotency violations

    XMLWordPrintable

Details

    • Bug
    • Status: Closed
    • Blocker - P1
    • Resolution: Fixed
    • 2.2.0
    • 2.2.1, 2.3.0
    • Replication, Storage
    • Fully Compatible
    • 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.

      Attachments

        Issue Links

          Activity

            People

              alerner Alberto Lerner
              ian@mongodb.com Ian Whalen
              Votes:
              9 Vote for this issue
              Watchers:
              19 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: