IJ01927: IMS JDBC WORKLOAD SPENDS UP TO 74% TIME IN DECIMALDATA.CONVERTPACKEDDECIMALTOLONG() METHOD

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  Customer ran IMS JDBC tests and reported that
  DecimalData.convertPackedDecimalToLong() DataAccessAccelerator
  method took about 74% of the profile time in IBM HealthCentre.
  

Local fix

• N/A
  

Problem summary

• The problem happens because the JIT-compiled method body has a
  strict packed decimal sign requirement: a hardware exception is
  triggered whenever the inputs have invalid signs. Because of
  this strict sign requirement, the IMS JDBC workload caused
  excessive hardware exceptions. As a result of this, up to 74% of
  the time was spent in exception handling in the
  DecimalData.convertPackedDecimalToLong() DAA method
  

Problem conclusion

• A fix to the JIT compiler has been delivered to change the way
  how DecimalData.convertPackedDecimalToLong() method is
  JIT-compiled. Its JIT-compiled method body will first sanitize
  the packed decimal inputs before performing
  long-to-packed-decimal conversions to avoid unnecessary hardware
  exceptions.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP5   (8.0.5.5)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

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

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

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