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  1. Core Server
  2. SERVER-41320

Oplog getmores can return 0 entries

    • Type: Icon: Bug Bug
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 4.4.0
    • Affects Version/s: None
    • Component/s: None
    • None
    • Replication
    • Fully Compatible
    • ALL

      Oplog getmores can return with 0 entries if there is nothing new in the oplog, rather than waiting for more entries to appear.

      Under some circumstances this can increase the latency of w:majority or w:2 operations, because the operation must wait for the round-trip of the getmore that returned 0 as well as the round trip for its oplog entry before getting acknowledgement that the operation has been committed on the secondaries. This impacts for example single-threaded clients that are issuing repeated writes in a loop as fast as possible.

        1. mongod-4.1.13-w2-plot.png
          mongod-4.1.13-w2-plot.png
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        2. mongod-4.1.13-w2-replsetupdatepos-plot.png
          mongod-4.1.13-w2-replsetupdatepos-plot.png
          113 kB
        3. mongod-master-fix-w2-ftdc.png
          mongod-master-fix-w2-ftdc.png
          110 kB
        4. mongod-master-fix-w2-plot.png
          mongod-master-fix-w2-plot.png
          96 kB

            Assignee:
            backlog-server-repl [DO NOT USE] Backlog - Replication Team
            Reporter:
            bruce.lucas@mongodb.com Bruce Lucas (Inactive)
            Votes:
            1 Vote for this issue
            Watchers:
            26 Start watching this issue

              Created:
              Updated:
              Resolved: