Re: The Truth About EGL

Walden,

i5/OS doesn't need Fast CGI because ILE provides the ability to leave programs activated (which is kind of what Fast CGI does but it's less efficient). We have a site we're replacing that uses Fast CGI and what that site does is start up a set number of processes for each CGI program and cycle between them. It performs well enough as long as it doesn't need to start up more processes. When that happens, performance tanks but that's more because of memory issues (each process allocates as much memory as it takes to start a given CGI program and have it sit idle) than anything else. Apache on i5/OS is able to reuse existing CGI jobs for multiple CGI programs which drastically reduces the amount of memory needed (i5/OS is better at memory management with stuff that's sitting idle than other OS' which also helps). Also, the biggest hit I usually see on start up for CGI apps is connecting to the database on another iSeries we have but once a connection is started in a particular job, it's shared by other programs running in that job so you don't take that hit very often.

Matt

________________________________________
From: web400-bounces@xxxxxxxxxxxx [web400-bounces@xxxxxxxxxxxx] On Behalf Of Walden H. Leverich [WaldenL@xxxxxxxxxxxxxxx]
Sent: Tuesday, December 18, 2007 9:19 PM
To: Web Enabling the AS400 / iSeries
Subject: Re: [WEB400] The Truth About EGL

CGI tends to get a bad rap (often rightly so) because it's based on the concept of one request per process lifetime. Creating a new process for each request is part of what makes CGI apps so easy to create, you don't have to worry about multi-threading issues or worry about the state of the process, it's always new. Think of CGI as being RPG calls where you seton LR after each call, it's slower, but it's always clean. :) There is also Fast-CGI, which is roughtly akin to calling return w/out LR in RPG :) Apache support FastCGI in general, but I don't know about the i5/OS version. More "modern" app servers support multiple requests as threads in a single process (or group of processes, often called a web-garden) but apps that aren't multi-thread capable can cause problems in these situations.

-Walden

--
Walden H Leverich III
Tech Software
(516) 627-3800 x3051
WaldenL@xxxxxxxxxxxxxxx <mailto:WaldenL@xxxxxxxxxxxxxxx>
http://www.TechSoftInc.com <http://www.techsoftinc.com/>
Quiquid latine dictum sit altum viditur. (Whatever is said in Latin seems profound.)

--
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email: WEB400@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.