I had an interesting issue with tomcat today on my VPS.
I added a new domain to my tomcat server configuration, and accidentally caused a circular reference in the alias section of one virtual host to another virtual host. By this I mean that one virtual host configuration had the same alias as in another host. I am assuming this made some web applications load up more than once, and therefore the server use more memory than would normally be required.
If you do this, first thing you'll notice is that the server performs poorly, and soon after starts to suffer from out of memory errors.
It took me a while to check the config, as at first I assumed that adding another domain had just pushed memory usage over the edge.
