IJ51645: MMAPPLYPOLICY: NO PARALLEL PIPED SORT WITH SINGLE NODE AFTER UPG

APAR status

• Closed as program error.

Error description

• Abstract: mmapplypolicy: no parallel piped sort with
  single node after upgrade to 5.2.0
  
  
  Reported In - Scale - 5.2.0.1
  OS details -  Ubuntu 22.04.4 LTS (Jammy Jellyfish),
  CentOS Linux 7 (Core)
  
  Known impact:
  Execution of mmapplypolicy became much slower in gpfs
  version 5.2.0.1. The same invocation takes more than
  45 minutes
  

Local fix

• Provided temporary fix code that can the customer try
  with this.  This is to replace existing
  /usr/lpp/mmfs/bin/tsapolicy on the node where
  mmapplypolicy is invoked.  Please save the original
  before replace for just in case.
  
  To use this:
  1) save the original tsapolicy
  e.g:  cp /usr/lpp/mmfs/bin/tsapolicy
  /usr/lpp/mmfs/bin/tsapolicy.org
  2) apply the fix on the node where mmapplypolicy is
  invoked.
  e.g: cp tsapolicy.5201_x  /usr/lpp/mmfs/bin/tsapolicy
  3) set the execution mode properly (same as the original
  one)
  chmod 500 /usr/lpp/mmfs/bin/tsapolicy
  
  Can the customer try with this?  This is to replace
  existing /usr/lpp/mmfs/bin/tsapolicy on the node where
  mmapplypolicy is invoked.  Please save the original
  before replace for just in case.
  
  To use this:
  1) save the original tsapolicy
  e.g:  cp /usr/lpp/mmfs/bin/tsapolicy
  /usr/lpp/mmfs/bin/tsapolicy.org
  2) apply the fix on the node where mmapplypolicy is
  invoked.
  e.g: cp tsapolicy.5201_x  /usr/lpp/mmfs/bin/tsapolicy
  3) set the execution mode properly (same as the original
  one)
  chmod 500 /usr/lpp/mmfs/bin/tsapolicy
  
  Which has resolved customer issue.
  

Problem summary

• When mmapplypolicy runs with single node, it runs as strictly
  local mode since 5.1.9.0.
  But it could show slower performance during sorting phase with
  large file system because it does not execute parallel sorting.
  

Problem conclusion

• There will be performance improvement in large file system when
  mmapplypolicy is run with single node only.
  

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