Is hosting a Netty Server inside Tomcat feasible/desirable?

Question

We building a Netty/NIO based service, and I'm considering the deployment of this service to our production environment. Our standard way of deploying services is as WARs, to be deployed inside Tomcats.

When I suggested the same approach here, I got shouts and complaints that "it shouldn't be done", because both Netty and Tomcat are servers, and "it doesn't make sense to host one server in another".

To me it makes perfect sense because it completely solves my deployment issue, as well as saves me from writing some other code. Why is it such a big "no no" ?

Answer 1

The dynamic WAR deploying and undeploying that Tomcat provides are designed for web applications. The Netty application you are trying to deploy into Tomcat is not a web application but just a separate server that only shares the VM memory. It means Tomcat has been repurposed into a generic microkernel such as OSGi.

However, I don't think it's a big problem. Since your company uses WAR as the standard deployment mechanism, it might be a good idea to reuse it. You don't even need to write some management functions like remote shutdown because Tomcat already provides them. All you need to do is to make sure all resources are freed up when undeployed.

Some people might not like this approach though. Ideally, there should be a common infrastructure for deploying and managing whatever application (aka microkernel), where even Tomcat is deployed as a module and the microkernel manages WAR directly instead Tomcat does. But that's a long way to go.