IV09840: 'CORRUPT TRAILER' IOEXCEPTION IN GZIPINPUTSTREAM.READTRAILER

APAR status

• Closed as program error.

Error description

• Error Message: While running Cognos Content Manager to process
  compressed data, the application throws an IOException with the
  error string "Corrupt GZIP trailer". This only happens
  intermittently (when system load is high), but once the symptom
  appears, the server must be restarted before it can function
  normally.
  The issue is only seen when the server is running on Java 5 (WAS
  6) on either z/Linux or z/OS.
  .
  Stack Trace: java.io.IOException: Corrupt GZIP trailer
    at java/util/zip/GZIPInputStream.readTrailer
    at java/util/zip/GZIPInputStream.read
    at java/io/FilterInputStream.read
    at com/cognos/cm/util/GzipInflater.inflate
  java.io.IOException: Corrupt GZIP trailer
    at java/util/zip/GZIPInputStream.readTrailer
    at java/util/zip/GZIPInputStream.read
    at java/io/FilterInputStream.read
    at com/cognos/cm/multipart/ResponseFileAttachment.write
  .
  

Local fix

• This issue only happens when the GZIPInputStream methods are
  inlined by the JIT compiler into the
  com/cognos/cm/util/GzipInflater.inflate method and/or the
  com/cognos/cm/multipart/ResponseFileAttachment.write method. It
  can be worked around by excluding the affected com/cognos/cm
  methods from JIT compilation.
  

Problem summary

• The problem is caused by a bug in the System z code generator in
  the Java 5 JIT compiler. It generates incorrect instructions to
  compare a long variable against an int variable that has been
  extended to 64 bits and stored into memory. The generated code
  miscalculates the memory address for the stored extended int
  value, and ends up performing an invalid comparison.
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR13 FP1
  .
  The JIT compiler has been updated to generate correct
  instructions for this scenario.
  .
  To obtain the fix:
  Install build 20111108 or later
  

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:

  PM64520

Fix information

• Fixed component name

  JAVA 5 JIT

• Fixed component ID

  620500124

Applicable component levels

• R500 PSY

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