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  1. Percona Server for MySQL
  2. PS-5966

Handler statistics are drifting

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    Details

    • Type: Bug
    • Status: Done
    • Priority: High
    • Resolution: Fixed
    • Affects Version/s: 5.7.26-29, 8.0.16-7, Not 5.6.x
    • Fix Version/s: 5.7.28-31, 8.0.18-9
    • Component/s: None
    • Labels:

      Description

      Hi, 

      It looked like we already fixed this bug: https://bugs.mysql.com/bug.php?id=90351

      But in MySQL 8.0.16 it still happening, we upgraded to 8.0.16 because basically many graphs were ruined because of this bug, but still happening, but not that frequent anymore maybe once in every few hours previously it was happening all the time:

      I have started Iwo's script on the master server to monitor the statistics and yes we can see it is happening:

       

      5468630320 < 5468650972 (Handler_commit)
      5468628952
      5468650972
      5468630320
      12136264379 < 12136310039 (Handler_external_lock)
      12136261349
      12136310039
      12136264379
      165444232 < 165444616 (Handler_prepare)
      165444214
      165444616
      165444232
      357644957 < 357646500 (Handler_read_first)
      357644853
      357646500
      357644957
      42022468474 < 42022518876 (Handler_read_key)
      42022464955
      42022518876
      42022468474
      85712119745 < 85712174300 (Handler_read_next)
      85712105821
      85712174300
      85712119745
      8663652932 < 8663667454 (Handler_read_prev)
      8663651572
      8663667454
      8663652932 
      

      But because we took MySQL 8 code I am pretty sure this could happen on Percona Server 8 as well, and it ruins most of the PMM graphs.

       

      We should review's oracle fix , why is this happening in MySQL 8 again.

       

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            Assignee:
            kamil.holubicki Kamil Holubicki
            Reporter:
            tibor.korocz Tibor Korocz
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              Updated:
              Resolved:

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