Detect the health of webserver and route traffic accordingly

Priya: Here's a setup that we used with some WebSphere (and other J2EE) apps that worked quite well. In our case we had several resources that we cared about: an instance of MQ that the app connected to and a couple of remote databases. If any of these were down or if our container wasn't able to connect for some reason, we'd want to take the server out of the pool.

 

 

Our approach was to write a basic servlet that would check database connectivity, fetch a simple message from the queue, etc. Then it would report back: UP or DOWN.

 

 

On the BigIP we simply created a monitor that pointed to our servlet (be sure and pass the HOST header to WebSphere, and I always add a Connection: close header as well), and added a "fallback host" to our http profile that we applied to the virtual server.

 

 

The fallback host setting basically means this: when all nodes are down, redirect to some other site. In the field, place the location you want them to get the 302 for.

 

 

Hope this helps, and good luck!

 

 

-Matt