An administrator needs to confirm correct operation of a server and track down problems as they occur.
One key place to search for information on problems is the log file. This is a file to which the servlet container will write log information generated by webMathematica. Under Tomcat, a typical location for the log file is <path-to-tomcat>/logs/localhost_log.YYYY-MM-DD.txt, where the filename includes the date. Under JRun, it is <path-to-jrun>/logs/default-event.log. For other servlet containers you will need to study the relevant documentation. If the log file is empty, it may indicate that the user running the servlet container does not have permission to write to the log file directory. The Unix command tail -f can be useful for monitoring output from this file.
The log file records serious errors; if your system does not function correctly at startup time, it would be good to look here. For example, if the configuration file is not found or the kernel cannot be launched, this will be recorded in the log file. Later, if there is a serious error that requires shutting down a kernel, this is also recorded.
The VerboseLogs configuration parameter selects between two levels of output to the log file. If it is set to false, each page access causes one line of information to be sent to the log file. This provides a convenient way to confirm that your site is running correctly. If VerboseLogs is set to true, a considerable amount of extra information is sent to the log file. This includes any messages the Mathematica kernel generates.
After your site is running, it is possible to modify the verbosity of logging and make other changes via the monitor, which will be described in the Kernel Monitor section.