PI69321: ENABLE VERBOSE GARBAGE COLLECTION BY DEFAULT

9.0.0.3: WebSphere Application Server traditional V9.0 Fix Pack 3
9.0.0.4: WebSphere Application Server traditional V9.0 Fix Pack 4
9.0.0.5: WebSphere Application Server traditional V9.0 Fix Pack 5
9.0.0.6: WebSphere Application Server traditional V9.0 Fix Pack 6
9.0.0.7: WebSphere Application Server traditional V9.0 Fix Pack 7
9.0.0.8: WebSphere Application Server traditional V9.0 Fix Pack 8
9.0.0.9: WebSphere Application Server traditional V9.0 Fix Pack 9
9.0.0.10: WebSphere Application Server traditional V9.0 Fix Pack 10
9.0.0.11: WebSphere Application Server traditional V9.0 Fix Pack 11
9.0.5.0: WebSphere Application Server traditional Version 9.0.5 Refresh Pack
9.0.5.1: WebSphere Application Server traditional Version 9.0.5 Fix Pack 1
9.0.5.2: WebSphere Application Server traditional Version 9.0.5 Fix Pack 2
9.0.5.3: WebSphere Application Server traditional Version 9.0.5 Fix Pack 3
9.0.5.4: WebSphere Application Server traditional Version 9.0.5 Fix Pack 4
9.0.5.5: WebSphere Application Server traditional Version 9.0.5 Fix Pack 5
WebSphere Application Server traditional 9.0.5.6
9.0.5.7: WebSphere Application Server traditional Version 9.0.5 Fix Pack 7
9.0.5.8: WebSphere Application Server traditional Version 9.0.5.8
9.0.5.9: WebSphere Application Server traditional Version 9.0.5.9
9.0.5.10: WebSphere Application Server traditional Version 9.0.5.10
9.0.5.11: WebSphere Application Server traditional Version 9.0.5.11

APAR status

• Closed as program error.

Error description

• Enable verbose garbage collection by default
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server for Distributed operating systems.   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Verbose garbage collection (verboseGC)  *
  *                      is disabled by default.                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Staring in version 9.0.0.3 WebSphere Application Server for
  Distributed enables verboseGC by default for the Application
  Server, Node Agent, and Deployment Manager server types; and
  when enabled, WebSphere Application Server will log
  verboseGC output to 10 sequential, rotating (i.e. rolling)
  "verbosegc" files which cumulatively consume about 100M of
  disk space per server process.
  This is a change in default behavior from previous
  releases wherein verboseGC is disabled by default for all
  server types, and when enabled, verboseGC output
  writes to the native process logs.
  "Verbose garbage collection" (verboseGC) is a setting in the
  Java virtual machine configuration for a server type, such as
  a Deployment Manager or Application Server.  When verboseGC is
  enabled in a server configration in releases prior to
  9.0.0.3, WAS supplies the standard java option "-verbose:gc"
  to the java command line when launching the server.  In
  9.0.0.3 when verboseGC is enabled WAS supplies the following
  standard and non-standard java command line arguments when
  launching a server.
  On Windows, Linux, AIX:
  -verbose:gc
  -Xverbosegclog:${SERVER_LOG_ROOT}\verbosegc.%seq.log,10,7000
  On Solaris, HP-UX:
  -verbose:gc
  -Xloggc:${SERVER_LOG_ROOT}\verbosegc.log
  -XX:+UseGCLogFileRotation
  -XX:NumberOfGCLogFiles=10
  -XX:GCLogFileSize=10M
  -XX:+PrintGCDateStamps
  -XX:+PrintGCDetails
  These options direct the JVM to write verboseGC diagnostic
  data to as many as 10 rolling "verbosegc" logs which
  cumulatively consume about 100M of file space.  The logs are
  created in the ${SERVER_LOG_ROOT} directory alongside the
  other server logs.  Notice that, on Windows, AIX, and Linux,
  the options specify 7000 garage collection events per log.
  Because the size of GC events will vary, the amount of
  cumulative file space consumed by verbosegc logs will also
  vary on these platforms.
  To revert verbose GC logging behavior to that of previous
  releases, disable the verbose garbage collection setting
  in the server's Java virtual machine configuration and enter
  the standard Java command-line option "-verbose:gc" (unquoted)
  in the Generic JVM Arguments field of the same Java Virtual
  Machine configuration.  If the Generic JVM Arguments field
  contains no additional arguments that control verbose garbage
  collection logging, then the server will direct verboseGC
  diagnostic data to a native process log.
  

Problem conclusion

• VerboseGC diagnostic data is critical to troubleshooting
  memory and performance problems, and the overhead is generally
  very low.  APAR PI69321 enables verboseGC by default to ensure
  diagnostic data is immediately available when such problems
  occur; and it redirects verboseGC output to rotating logs to
  both limit the amount of data collected and to reduce the risk
  that native process logs exhaust the available file space over
  the life of a server process.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 9.0.0.3.  Please refer to the Recommended Updates
  page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels

• R900 PSY

     UP