Tomcat and maximum number of requested accepted

Question

Is there a way to configure Tomcat to reject a request after a specific threshold number? E.g. after 506 requests start rejecting.
Is there such an option or am I supposed to write code for this?

Answer 1

Tomcat's connectors can be configured to only service a certain number of requests simultaneously -- that's configured as the maxConnections attribute of a <Connector> in server.xml. (You can also configure the acceptCount but that's actually a queue of connections that the OS maintains that pile-up after maxConnections has been reached). This limits simultaneous connections to Tomcat across all URLs -- that is, it's just total connections that are being limited.

If you want to limit the number of simultaneous connections to a specific URL (or specific set of URLs for that matter), you may have to write your own code. I've heard that Spring Security has a lot of QOS (quality-of-service) features like this that you might be able to use without writing your own code.

Otherwise, you'll be forced to write your own code -- probably a Filter that simply keeps track of how many requests are in-progress and then rejecting those that come in after some limit has been reached. Beware of synchronization issues with counters being used across threads.