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  1. Percona Server for MongoDB
  2. PSMDB-587

Add options to control the size of several WiredTiger hash arrays concerned with data handles and one for session cursor cache

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    Details

    • Type: New Feature
    • Status: Done
    • Priority: Medium
    • Resolution: Fixed
    • Affects Version/s: 3.6.x
    • Fix Version/s: 4.0.19-12, 4.2.7-7, 3.6.18-6.0
    • Component/s: Core
    • Labels:
      None
    • Needs Review:
      Yes

      Description

      When there are very high number of collections on a node (say >100,000) the iteration of all datahandles in early stages of a WiredTiger checkpoint can take a considerable amount of time (think > 10s).

      At first this is not 100% blocking to client db ops but the dhandle (data-handle) lock grows to be 100% over the course of some time and then it is. So if this phase takes say 12 secs, there can be 4~5 seconds towards the end where the db ops are blocked (not sure if logical locking or just effective locking by CPU resource saturation).

        Attachments

        1. psmdb-mongostat-0.log
          245 kB
        2. psmdb-mongostat-1.log
          330 kB
        3. psmdb-mongostat-2.log
          239 kB
        4. psmdb-mongostat-3.log
          314 kB

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              Assignee:
              igor.solodovnikov Igor Solodovnikov
              Reporter:
              akira.kurogane Akira Kurogane
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                Resolved:

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