IV11142: SSM oraEffMemBufCache may sometimes exceed 100% when it should not

IBM Netcool System Service Monitor SSM 4.0 Fix Pack 13 README 4.0.0-TIV-SSM-FP0013
IBM Netcool System Service Monitor SSM 4.0 Fix Pack 14 README 4.0.0-TIV-SSM-FP0014
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 1 README 4.0.0.14-TIV-SSM-IF0001
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 2 README 4.0.0.14-TIV-SSM-IF0002
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 3 README 4.0.0.14-TIV-SSM-IF0003
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 4 README 4.0.0.14-TIV-SSM-IF0004
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 5 README 4.0.0.14-TIV-SSM-IF0005
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 6 README 4.0.0.14-TIV-SSM-IF0006
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 7 README 4.0.0.14-TIV-SSM-IF0007
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 8 README 4.0.0.14-TIV-SSM-IF0008
IBM Netcool System Service Monitor SSM 4.0 Interim Fix 1 README 4.0.0.15-TIV-SSM-IF0001

APAR status

• Closed as program error.

Error description

• ISSUE:
  Oracle Buffer Cache Hit Ratio ranges from 1% to 7000%
  
  REASON :
  oraEffMemBufCache is calculated as:
  
  (SLR - (PR - PRD) ) / SLR
  
  Where:
  SLR = Session Logical Reads
  PR  = Physical Reads
  PRD = Physical Reads Direct
  
  If the value of SLR wraps and is also less than PR - PRD the
  top half of the fraction becomes negative. Internally this
  was using unsigned arithmetic and a negative number turns into
  a large positive number.
  
  This value is larger than SLR and the oraEffMemBufCache ends up
  being much greater than 100%.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All SSM 4.0 Oracle subagents                                 *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * The oraEffMemBufCache made some invalid assumptions in its   *
  * calculation. When the Session Logical Read wraps it causes   *
  * the oraEffMemBufCache to be greater than 100%. This has been *
  * fixed  so that the Session Logical Read values should not    *
  * wrap and cause this problem to occur.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Fix Pack 13 for SSM 4.0                           *
  ****************************************************************
  

Problem conclusion

• The internal calculations have been fixed to ensure that Session
  Logical Reads doesn't wrap and cause greater than 100% values
  for oraEffMemBufCache.
  
  
  The fix for this APAR is contained in the following maintenance
  packages:
    | fix pack | 4.0.0-TIV-SSM-FP0013
  

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

  NETCOOL SYS SVC

• Fixed component ID

  5724P4300

Applicable component levels

• R400 PSY

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