IBM WebSphere Application Server Performance Cookbook

IHS & WAS Plugin Performance

  1. In the conf/httpd.conf file, find the section for mod_mpmstats.c and change ReportInterval to: 
    ReportInterval 30
  2. In the conf/httpd.conf file, find the CustomLog directive for your access_log. By default this is: 
    CustomLog logs/access_log common
    The last part of that line, in this example "common" is the name of the LogFormat to use. Find this LogFormat. By default, this may be: 
    LogFormat "%h %l %u %t \"%r\" %>s %b" common
    Change this to, for example: 
    LogFormat "%h %l %u %t \"%r\" %>s %b %D \"%{WAS}e\" %X %I %O %^FB" common
  3. Archive and truncate existing access.log, error.log, and http_plugin.log files.
  4. Save httpd.conf and restart the IHS servers (either gracefully or fully).
  5. Reproduce the problem.
  6. Gather
    1. access.log
    2. error.log
    3. http_plugin.log
    4. httpd.conf
    5. plugin-cfg.xml
  7. Review all logs for any errors, warnings, etc.
  8. Review the response times. Try to isolate the problem to particular requests (duration or volume).
  9. Review mpmstats.
  10. Review incoming rate and distribution of requests (see Web Servers).
  11. Review http_plugin.log:
    1. scanplugin.pl can help find "interesting" Plugin requests (timeouts, bad status codes, non-WAS delays)