Re: CGIDEV2 performance versus Net.Data

["Nathan M. Andelin" <nandelin@xxxxxxxxxxxxxxxxxxx>]

> From: "Mel Rothman" <mel@rothmanweb.com>

> It appears that you are trying to prove that CGI doesn't scale well.

Not really.  I want to understand CGI's scalability.  This discussion has
helped.  It seems that under OS/400 the mechanics are in place to enable CGI
to scale well.

> As Leif points out, what's really being used is virtual memory.

I don't understand this.  Or how it relates to the issue of scalability.

> this is a problem when activity gets so high that excessive
> paging occurs.

If CGI programs are active, but not running, would that increase the
occurance of paging?

> As previously pointed out, this can and should be controlled
> by throttling the server.

That makes sense.  It's an imposed bottleneck.

> Regarding design:

I won't relist your design points.  They're all excellent.

> It's not clear whether you approach supports a remote
> application server.

Not presently.  But it wouldn't take much to add remote routing via data
queue.

> In theory, your approach should be fast and efficient too.

The HTTP Server Plug-in has the advantage of using static procedure calls
within a thread as opposed to dynamic program calls within a job.  It
appears to enhance performance.  But I'm not sure by how much.

The Relational-Web version of my sample application uses about 80% less CPU
time than the Easy400 version, and about 90% less CPU time than the Net.Data
version.  I've tried to optimize each of the three (3) versions.

I'm not sure how significant those percents are.  Is it important to people?
Perhaps not.  A tool can only do so much.  It's really up to the programmer
to create efficient software with the tools provided.

Thanks,

Nathan M. Andelin
www.relational-data.com