IT33998: PERFORMANCE ENHANCEMENT FOR SYSTEM STATE BACKUP PRODUCER THREAD

APAR status

• Closed as program error.

Error description

• During system state backup, the backup-archive client producer
  thread examines (checks) each system state file for hardlinks.
  For each file, the check can take several milliseconds, leading
  to longer time spent in the producer thread, and overall longer
  elapsed processing time.
  
  Although performance characteristics greatly depend on the
  run-time environment, this issue can be more severe when the
  system state has an unusually large number of files, such as
  400000 files. Long run-time durations can occur even if very few
  files are backed up and network throughput is otherwise not the
  bottleneck.
  
  A SERVICE trace will show several milliseconds transpiring
  between time1 and time2 of two lines, which occur throughout the
  trace for each system state file:
  
    <date> <time1> Ýpid¨ Ýtid¨ : ..\..\common\filem\
      filerdelim.cpp( 102): Working with file <filename>
    <date> <time2> Ýpid¨ Ýtid¨ : ..\..\common\winnt\
      psfssub.cpp(3647): psIsHardLink(): filename has 1 link(s)
  
  For example, note the 10 millisecond time gap between these
  lines:
  
    <date> 18:06:40.416 Ýpid¨ Ýtid¨ : ..\..\common\filem\
      filerdelim.cpp( 102): Working with file <filename>
    <date> 18:06:40.426 Ýpid¨ Ýtid¨ : ..\..\common\winnt\
      psfssub.cpp(3647): psIsHardLink(): filename has 1 link(s)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * IBM Spectrum Protect backup-archive client versions 7.1.6,   *
  * 7.1.8, 8.1.4, 8.1.6, 8.1.8, 8.1.9 and 8.1.10 on Windows      *
  * platform.                                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See ERROR DESCRIPTION                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * This issue is projected to be fixed in the IBM Spectrum      *
  * Protect backup-archive client 8.1.11 version on Windows      *
  * platform.                                                    *
  * Note that this is subject to change at the discretion of     *
  * IBM.                                                         *
  ****************************************************************
  

Problem conclusion

• The system state specific subroutine that handles the hard links
  has been optimized so the overall performance of the sysetm
  state backup has been improved.
  

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:

Modules/Macros

• DSM      DSMC     DSMCSVC  DSMAGENT
  

Fix information

• Fixed component name

  TSM CLIENT

• Fixed component ID

  5698ISMCL

Applicable component levels