IJ55184: READ PERFORMANCE REGRESSION IN SCALE 5.2.3 PTF1 AND PTF2

APAR status

• Closed as program error.

Error description

• Scale 5.2.3 PTF1 and PTF2 contain a code change leading to
  possible slower read performance.
  The problem exists in 5.2.3 PTF1 and  the fix is in 5.2.3 PTF2
  

Local fix

• Do not use Scale 5.2.3 PTF1 or PTF2.
  

Problem summary

• Scale 5.2.3 PTF1 and PTF2 contain a code change leading to
  possible slower read performance.
  
  The problem exists in 5.2.3 PTF1 and  the fix is in 5.2.3 PTF2
  

Problem conclusion

• This problem is fixed in 5.2.3.2
  To see all Spectrum Scale APARs and their respective
  Fix solutions refer to page: 
  https://public.dhe.ibm.com/storage/spectrumscale/spectrum_scale
  _apars.html
  
  Benefits of the solution:
  The fix will avoid the performance regression.
  
  Work Around:
  Do not use Scale 5.2.3 PTF1 or PTF2.
  
  Problem trigger:
  Any regular read workload can incur additional overhead. This
  has been specifically observed with the ior hard read benchmark,
  
  but could affect any read workload.
  
  Symptom:
  Slower performance than expected.
  
  Platforms affected:
  ALL Linux OS environments and "Windows/x86_64"
  
  Functional Area affected:
  All Scale Users
  
  Customer Impact:
  High Importance
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  SPEC SCALE STD

• Fixed component ID

  5737F33AP

Applicable component levels