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  1. Core Server
  2. SERVER-36496

Cache pressure issues during oplog replay in initial sync

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    Details

    • Type: Bug
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Backlog
    • Component/s: None
    • Labels:
      None

      Description

      During oplog replay in initial sync we don't advance the oldest timestamp. This can pin a lot of data in the cache. Resulting symptoms include

      • slow initial sync due to resulting cache churn
      • growth of lookaside (cache overflow) table and corresponding file WiredTigerLAS.wt
      • in extreme cases cache-full hangs were observed. This was believed fixed with SERVER-33191, but we should be alert for new occurrences of this issue.

        Attachments

          Issue Links

          is caused by

          Improvement - An improvement or enhancement to an existing feature or task. WT-4016 Measure and improve lookaside performance with stable_timestamp set

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

          Bug - A problem which impairs or prevents the functions of the product. SERVER-33191 Cache-full hangs on 3.6

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

          Bug - A problem which impairs or prevents the functions of the product. SERVER-34900 initial sync uses different batch limits from steady state replication

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

          Bug - A problem which impairs or prevents the functions of the product. SERVER-34942 Stuck with cache full during oplog replay in initial sync

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

          Bug - A problem which impairs or prevents the functions of the product. SERVER-36238 replica set startup fails in wt_cache_full.js, initial_sync_wt_cache_full.js, recovery_wt_cache_full.js when journaling is disabled

          • Minor - P4 - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. SERVER-34938 Secondary slowdown or hang due to content pinned in cache by single oplog batch

          • Major - P3 - Major loss of function.
          • Investigating

            Activity

              People

              Assignee:
              backlog-server-repl Backlog - Replication Team
              Reporter:
              bruce.lucas Bruce Lucas
              Participants:
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                Dates

                Created:
                Updated: