The mod_jk source distribution contains two perl scripts in the tools/reports directory which can be used to analyze the mod_jk logs, save statistical data, and generate report graphs.

tomcat_trend.pl log_dir archive_dir

Script for analyzing mod_jk.log data when logging tomcat request data using the JkRequestLogFormat Apache mod_jk configuration. Generates statistics for request latency and errors. Archives the generated data to files for later use in long term trend graphs and reports.

tomcat_reports.pl archive_dir reports_dir

Script for generating reports and graphs using statistical data generated by the tomcat_trend.pl script. The following graphs are created:

• tomcat_request.png - Long term trend graph of total number of tomcat requests handled.
• tomcat_median.png - Long term overall trend graph of tomcat request latency median.
• tomcat_deviation.png - Long term overall trend graph of tomcat request mean and standard deviation.
• tomcat_error.png - Long term trend graph of requests rejected by tomcat. Shows requests rejected when tomcat has no request processors available. Can be an indicator that tomcat is overloaded or having other scaling problems.
• tomcat_client.png - Long term trend graph of requests forward to tomcat which were aborted by the remote client (browser). You will normally see some aborted requests. High numbers of these can be an indicator that tomcat is overloaded or there are requests which have very high latency.

A great deal of statistical data is generated but at this time only long term trend graphs are being created and no reports. This is only a start. Many more graphs and reports could be generated from the data. Please consider contributing back any new reports or graphs you create. Thanks.

These perl scripts depend upon the following perl modules and libraries:

• GD 1.8.x graphics library http://www.boutell.com/gd/
• GD 1.4.x perl module
• GD Graph perl module
• GD TextUtil perl module
• StatisticsDescriptive perl module