Uploaded image for project: 'Lustre'
  1. Lustre
  2. LU-5197

A performance regression of "FileRead" metadata operation

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: Lustre 2.6.0, Lustre 2.5.2
    • Fix Version/s: Lustre 2.6.0
    • Labels:
    • Severity:
      2
    • Rank (Obsolete):
      14517

      Description

      There is a perforamnce regression of "FileRead" metadata operation caused by fixes of LU-4398.
      Please see below performance difference with/without LU-4398 patches.

      It's simple mdtest run on single client with single thread.

      #mpirun -np 1 -ppn 1 -hostfile ./hostfile ./mdtest -n 100000 -i 1 -p 5 -u -v -F -d mdtest.out
      
      v2_5_2_RC1
      
      SUMMARY: (of 1 iterations)
         Operation                      Max            Min           Mean        Std Dev
         ---------                      ---            ---           ----        -------
         File creation     :       3478.187       3478.187       3478.187          0.000
         File stat         :       4514.273       4514.273       4514.273          0.000
         File read         :        515.113        515.113        515.113          0.000
         File removal      :       6499.513       6499.513       6499.513          0.000
         Tree creation     :       3908.951       3908.951       3908.951          0.000
         Tree removal      :        428.646        428.646        428.646          0.000
      
      v2_5_2_RC1 + revert "LU-4398 mdt: acquire an open lock for write or execute" (97bfe7a3c0fc74fb0e56cbc1ea9cb827fb657b48)
      SUMMARY: (of 1 iterations)
         Operation                      Max            Min           Mean        Std Dev
         ---------                      ---            ---           ----        -------
         File creation     :       3575.570       3575.570       3575.570          0.000
         File stat         :       4708.052       4708.052       4708.052          0.000
         File read         :       5348.987       5348.987       5348.987          0.000
         File removal      :       6509.834       6509.834       6509.834          0.000
         Tree creation     :       3816.473       3816.473       3816.473          0.000
         Tree removal      :        400.143        400.143        400.143          0.000
      

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                jhammond John Hammond
                Reporter:
                ihara Shuichi Ihara (Inactive)
              • Votes:
                0 Vote for this issue
                Watchers:
                13 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: