Re: CGI vs JSP...

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Seth Newton
> 
> CGI doesn't always scale well?  Under what conditions?
> 
> RPG is the native, fast way to do anything on the 400.

Hi Seth!  I've stayed out of this conversation because everybody knows my
personal bias, which is strongly towards JSP/servlets for a number of
reasons.  One is that RPG-CGI doesn't handle the multi-threaded nature of
web applications very well.  Once you get more users than you have CGI jobs,
there are issues of thread synchronization which cause waits.

The only way I know of getting around this is to be sure you have enough
jobs for users, and in fact in my JSP architectures I typically start one
server job per HTTP session to handle all RPG requests.


> In general, I have seen RPG-CGI scale better than JSP.  If it's the same
> box, and the same type of application, you will be able to put more users
> on it, if it's written in RPG compared to Java.

Not if it's a thin layer of Java communicating to a RPG back end for
business logic.  The thin Java layer (which does little more than push
messages to and from the RPG and translate data between EBCDIC, Unicode and
ASCII) gets compiled to machine code very quickly JIT compiler and once
that's done, it's super fast, even on WebSphere (although as Aaron points
out, there's a LOT less overhead with Tomcat).

Joe