Monitor Tomcat Servlet Logs

Tomcat writes counter information from each of the main servlets to its catalina.out once a minute.

Example output:

WARN : [Thread-][20180510 20:57:05.501 +0100] [CReporterThread.java]:136 +|MoogPoller read [16722] MooMs messages in the last [60] seconds.|+
WARN : [Thread-][20180510 20:57:07.169 +0100] [CReporterThread.java]:136 +|Graze handled [55] requests in the last [60] seconds.|+
WARN : [Thread-][20180510 20:57:10.181 +0100] [CReporterThread.java]:136 +|MoogSvr handled [86] requests in the last [60] seconds.|+
WARN : [Thread-][20180510 20:58:03.197 +0100] [CReporterThread.java]:136 +|Situations similarity component calculated similarities for [264] situations in the last [60] seconds.|+

The counters are:

  • Number of MoogSvr requests in the last minute (i.e. number of standard UI requests made).

  • Number of Moogpoller MooMs messages in the last minute (i.e. number of messages read from the bus).

  • Number of Graze requests in the last minute.

  • Number of similar Situations calculated in the last minute.

In a healthy system that is processing data:

  • The Moogpoller count should always be non-zero.

  • The MoogSvr and Graze counters may be zero, but should reflect the amount of UI and Graze activity.

  • The similar Situations counter may be zero but should reflect the number of similar Situations that are occurring in the system.