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  1. Core Server
  2. SERVER-45626

Consistent Oplog Locking Rules

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    Details

    • Type: Task
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 4.7.0, 4.4.2
    • Component/s: None
    • Backwards Compatibility:
      Fully Compatible
    • Backport Requested:
      v4.4
    • Epic Link:
    • Sprint:
      Repl 2020-03-09, Repl 2020-03-23
    • Linked BF Score:
      23

      Description

      In principle we should only need the Global IS/IX lock to read/write the oplog. However, see SERVER-44906, we're inconsistent. Furthermore, there are cases our code requires a DB and Collection lock in order to get a Collection pointer to the oplog, although this is not fundamentally necessary.

      Inconsistent locking invites mistakes: deadlocks, race conditions, and unnecessary waiting.

        Attachments

          Issue Links

          causes

          Bug - A problem which impairs or prevents the functions of the product. SERVER-47959 Retry JournalFlusher oplog reads on WriteConflictExceptions caused by concurrent {full:true} validate command on the oplog collection

          • Major - P3 - Major loss of function.
          • Closed
          depends on

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-44906 Rollback should take global write lock while truncating oplog

          • Major - P3 - Major loss of function.
          • Open
          is related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-46930 AutoGetOplog doesn't acquire collection IX lock correctly for non-document-locking engines

          • Major - P3 - Major loss of function.
          • Closed
          links to

          Web Link Brainstorming Page

            Activity

              People

              Assignee:
              lingzhi.deng Lingzhi Deng
              Reporter:
              dbeng-pm-bot PM Bot
              Participants:
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                Dates

                Created:
                Updated:
                Resolved: