IV73609: READING ZOS SVCDUMPS WITH JDMPVIEW DIRECT FROM MVS DATASETS IS V ERY SLOW

APAR status

• Closed as program error.

Error description

• Error Message: Using jdmpview to read a large SVCDUMP direct
  from an MVS dataset is very slow, typically taking more than 30
  minutes elapsed time to open a 6Gb SVCDUMP.
  .
  Stack Trace: 4XESTACKTRACE         at
  com/ibm/jzos/ZFile.fseeko(Native Method)
  4XESTACKTRACE         at
  com/ibm/jzos/ZFile.seek(ZFile.java:1447(Compiled Code))
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/zebedee/dumpreader/Dump$Rarf.rea
  d(Dump.java:681(Compiled Code))
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/zebedee/dumpreader/Dump.read(Dum
  p.java:438(Compiled Code))
  4XESTACKTRACE         at
  javax/imageio/stream/ImageInputStreamImpl.readFully(ImageInputSt
  reamImpl.java:362(Compiled Code))
  4XESTACKTRACE         at
  javax/imageio/stream/ImageInputStreamImpl.readFully(ImageInputSt
  reamImpl.java:372(Compiled Code))
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/zebedee/dumpreader/Dump.initiali
  ze(Dump.java:311(Compiled Code))
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/zebedee/dumpreader/Dump.<init>(D
  ump.java:194)
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/zebedee/dumpreader/Dump.<init>(D
  ump.java:136)
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/tdump/TDumpReader.processDump(TDumpRea
  der.java:97)
  4XESTACKTRACE         at
  com/ibm/j9ddr/corereaders/CoreReader.readCoreFile(CoreReader.jav
  a:82)
  4XESTACKTRACE         at
  com/ibm/j9ddr/view/dtfj/image/J9DDRImageFactory.getImage(J9DDRIm
  ageFactory.java:114)
  4XESTACKTRACE         at
  com/ibm/dtfj/image/j9/ImageFactory.foundImage(ImageFactory.java:
  357)
  4XESTACKTRACE         at
  com/ibm/dtfj/image/j9/ImageFactory.getImage(ImageFactory.java:19
  1)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/commands/OpenCommand.imagesFromCommandLine(
  OpenCommand.java:102)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/commands/OpenCommand.run(OpenCommand.java:7
  0)
  4XESTACKTRACE         at
  com/ibm/java/diagnostics/utils/Context.tryCommand(Context.java:1
  30)
  4XESTACKTRACE         at
  com/ibm/java/diagnostics/utils/Context.execute(Context.java:86)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/CombinedContext.execute(CombinedContext.jav
  a:162)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/CombinedContext.execute(CombinedContext.jav
  a:146)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/Session.imageFromCommandLine(Session.java:5
  82)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/Session.sessionInit(Session.java:194)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/Session.<init>(Session.java:154)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/Session.getInstance(Session.java:150)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/DTFJView.launch(DTFJView.java:39)
  4XESTACKTRACE         at
  com/ibm/jvm/dtfjview/DTFJView.main(DTFJView.java:34)
  .
  A call stack obtained using Health Centre or by generating a
  Java dump (javacore) shows that the jdmpview code is spending
  most of its time in JZOS file seek() or read() operations.
  

Local fix

• If disk space allows, copy or move the SVCDUMP to an HFS file
  system before opening it in jdmpview.
  

Problem summary

• The problem is caused when jdmpview is reading an SVCDUMP
  dataset using the JZOS APIs.
  

Problem conclusion

• The jdmpview code has been updated to read SVCDUMP datasets in a
  more efficient way.
  .
  This APAR will be fixed in the following Java Releases:
     7 R1 SR3 FP10  (7.1.3.10)
     6 R1 SR8 FP7   (6.1.8.7)
     8    SR1 FP10  (8.0.1.10)
     7    SR9 FP 10 (7.0.9.10)
  .
  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

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R270 PSY

     UP

• R260 PSY

     UP