I dare say there are very few web servers left on the Internet. I think you’d have to spend a considerable amount of time trying to actually find one.
Now, given that you’re reading this on a web server, and there are obviously millions of websites, you may be asking yourself what the heck is he talking about?
I think what we consider web servers are actually application servers. I’ll ‘splain.
The server that lbdigest.com sites on runs the web serving software Apache. However, it also runs PHP, which combined with Apache forms an application server. Blogs, Wikipedia, webmail, photogalleries, social networking sites, they’re all applications. Web serving is the easy part, but a web server (Apache, IIS, etc.) is pretty useless by itself these days. Application platforms such as PHP, ASP, Java/Tomcat, .NET, etc., give the web its power.
It used to be that major websites had a 3-tier architecture. You had web servers, app servers, and database servers.
3-Tier Architecture
I haven’t seen that in a while. Most everything nowadays is a 2-tier architecture. The web and app layer are combined, although the database server is still typically separate.
2-Tier Modern Architecture
In the case of lbdgiest, web/app/database are all on the same server. So while calling this server a web sever isn’t inaccurate, a more accurate description would be that it’s an application server. I think you’d have a hard time finding a web server on the internet that isn’t also an application server. After all, when is the last time you saw a static web site?
1997 called, and they want their static web page back.
What about all the web servers out there serving static content such as images? Remove them and the web will look like 1994 called to get HTML back
Tony,
Great point. I think we could sum it all up as “All web servers (today) are application servers, but not all application servers are web servers” primarily because while web servers can be app servers via PHP, ASP, etc… app servers can’t always easily serve up simple images/static HTML. It’s all done via applications, which is much more complex than need be in the case of images/static content.
But with PHP, ASP, RoR, we could be seeing the beginnings of the end of complex, heavy application servers as lightweight languages take over web application development, even inside the enterprise (a la JSP, .NET).
Lori
We use resin as our app server and it’s a memory hog. Thus we spread this out over many servers on our tier 2 and retain a traditional tier 1 apache farm. An LB divvies the load across the web servers and the web servers divvy the load across application servers in a many-to-many relationship.
Hi Tony,
I read your book a few years ago – I found it very good.
When I first readd this I thought – hang on a minute, but then realised your trin of thought. VG, by your definition almost all web servers are indeed application servers.
cheers
Tony Murphy