Recently, I was asked to reorganize some of our Web applications to improve their stability. The major push was to get each of our applications running in its own instance of Tomcat. These applications all are in various stages of development, and if a single instance allocates all of the memory available, the entire Tomcat server must be restarted. This, in turn, brings down all of the other applications.

An obstacle to running multiple instances is each instance would have to run on a unique port. Enter Apache’s Web server. With the use of mod_jk, we were able to forward requests to specific hosts and contexts to the respective running instance of Tomcat.

Pulling all of this together was not the hardest thing I’ve done; however, it did prove challenging due to a lack of documentation. By no means, though, is this statement a stab at any of the development teams. In fact, the developers themselves helped me on numerous occasions when I found myself in over my head. When the documentation had me confused or I could not find exactly what I was looking for, I would head over to #tomcat or #apache on irc.freenode.org and pose my question there. Usually, I received a response within minutes.

The following software was used for the purposes of this article. See the resources section at the end of this article for download locations:

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Source : article by Daniel McCarthy,Linux Journal