Lambda Probe
Friday, August 29th, 2008Always eager for any clue of what Tomcat thinks it is doing, I downloaded Lambda Probe It was built to monitor Tomcat performance and it is a beautiful and easy-to-use tool. It was last updated in 2006, a lifetime ago, but judging by the forum activity, it still enjoys wide use. It installs as a war and provides a nice web interface that shows, among other things, thread information, database connection usage, some limited visitor stats, charts for traffic volume, access to log files and log tails and much more.
It is very easy to install.
One thing that pleased me immediately: It shows insight into individual application settings such as session timeout and even the list of jar files that the classloader has loaded. This is so much nicer than opening up some properties file some place to check settings.
And Context attributes. and, good god… a drillable list of every session and the session attributes and values within. I’m in tears.
It doesn’t seem to have backend storage to allow you to look back over time at performance as this unanswered question from the forums hints at:
Is there a way to run a report so I would not need to rely on monitoring the system in real time?
Good question.

