Servers

[Arathi Raj]

Hi,
Can anbody tell the diffrence between web server and application server. If we have to run a servlet or JSP does web server and application server should contain servlets and jsp engines. Do clarify me doubt.
Thanks

[Dani Mazzuca]

Hi,
web-server: supports servlets and JSP

application server: supports not only Servlets and JSP, but also EJB and J2EE.

Dani

[Jessica Sant]

actually Dani, that's close but not quite right:
a web server serves up static content: HTML, images, that kind of thing. It usually provides stuff like security, administration and what not too. But in its most elementary form, a webserver supports HTTP.
an application server serves dynamic content produced by Java Servlets, JSPs, and EJBs. Fully J2EE compliant application servers (BEA Weblogic, IBM WebSphere, etc.) can handle all 3, something like Tomcat only supports JSPs and Servlets and is called a servlet container or a servlet engine.
Hope that helps!
[ August 02, 2003: Message edited by: Jessica Sant ]

[Roger Chung-Wee]

The servet container can be considered part of the web server. In my department, developers set up Tomcat as standalone, ie Tomcat's integral web server and servlet container serve up both the static and dynamic stuff for development. For production, the only container we use is WebLogic which is out-of-process (as a separate process) with the web server, so the web server loads a plug-in to communicate with WebLogic.
You can also have the servlet container running in-process with the web server. The requires the web server to load a JVM to run the servlet container (which therefore runs in the same address space as the web server). This gives the best performance but my understanding is that this isn't as stable as running the web server and servlet container in separate processes.
In both the latter modes, the web server handles to static stuff and the servlet container the dynamic stuff.
[ August 03, 2003: Message edited by: Roger Chung-Wee ]