Tuesday, July 24, 2007

Lambda Probe - Manage Tomcat with Simplicity

Apache Tomcat is arguably the most popular servlet container in use today. It has a well-established user base and is usually one of the first to implement new Servlet and JSP JSR specifications. Tomcat comes bundled with the Manager App that allows to perform management tasks such as deployment, reloading etc. of webapps and other related services. The Manager App also provides an interface for integration with Ant and in the future there are plans to also provide a web service interface. The browser-based interface is functional but seems a little lacking especially for monitoring the Tomcat and JVM runtime. This space has been neatly filled by an open source project called Lambda Probe. Lambda Probe installs as just another web application under Tomcat and provides a clean, simple visual interface for core administration and monitoring.

Along with performing the usual tasks such as listing, deploying, reloading and un-deploying webapps, Lambda Probe provides comprehensive system monitoring information, JMX integration to monitor memory usage, connector stats for HTTP requests made and clustering information. Another useful feature is browsing the Tomcat log files which can be tailed in real time. Lambda Probe also provides an Availability Quick Check. Quick check is an instant way of checking the availability of the Tomcat server against three primary parameters: data source availability, free memory availability and file creation capability.