Deployment of static content

Question

I have to do a design decision for deployment here is the requirement

1. There is a web server and a app-server(JBOSS 5.1)
2. Application dinamic content should be there in the app server
3. Web server should contain the static content like html, pdf, images etc. (As per client)

My Questions:

• First of all is this a correct approach ?
• we have a app server why do we need another webserver?
• If we use the web server to hide the app server why do we need to put the static content to the web server?

Thanks in advance

Amit

Answer 1

At a small enough scale, it doesn't matter. If your workload is a few dozen employees using an internal web service that doesn't require a lot of resources per request, then do whatever you can deploy quickly. that might mean serving static content through a handler in your web-app, on a single server.

When you start to scale up, things that didn't matter before become noticeable.

The first thing that becomes noticeable on the above configuration (static content handled by the web-app) is that pages take a lot longer to load. That's because only one part of the page is actually dynamic, the HTML itself, but images, javascript, css, and whatever other odds and ends your page includes are also following the same lifecycle.

One thing you can do to improve things is to serve the static content intelligently in your handler to take advantage of caches and proxy servers, by setting the Expires and ETag headers, and returning 304 Not Modified when appropriate.

But that's all a static web server does already. Plus a static web server can be significantly better optimized at that specific workload. When you really start to scale up, shifting this workload to another host, so that the app server never even sees it, is one of the easiest ways to extract more performance from your web-app for very little cost.

Answer 2

Yes, this is an appropriate approach. By putting the static content on the (static content) web server as opposed to the app server, it reduces the potential load on the app server; web requests for dynamic content can be cleanly passed through to the app server with nearly no effort.