mod_jk/tomcat 4.1.18 annoyances
Some issues with the most recent Tomcat and mod_jk:
1. The oldish app we’re using requires Tomcat to have the following set in the web.xml: enablePooling false. I’m told the app was written to the old specification, and pooling is one of the new things being done with Tomcat 4.1. This took some time to figure out, since I don’t know much about the subtleties of JSPs.
2. The mod_jk upgrade failed badly. The new mod_jk 1.2.2 didn’t work, and dropping back to 1.2.1 and 1.2.0 didn’t fix the problem. I’m getting an error in mod_jk.out that looks like: “wc_get_worker_for_name, done did not found a worker”. Google searches didn’t show anything useful, and I suspect that the problem isn’t talking to Tomcat — tcpdump against the worker port didn’t show traffic — but starting the worker in the first place.
I used a mod_proxy trick to get around this, basically using Proxy statements in place of what would be jkMount ones. This works well enough, and Tomcat isn’t serving static content anyway. I believe this isn’t used more often because mod_proxy doesn’t support persistent connections and SSL environmental information, and so on. This shouldn’t matter for the application we’re running, though, since it doesn’t do anything fancier than HTTP/1.1. Here’s a document on using various connectors from Apache to Jetty, including mod_proxy.