Server spec

[Brock Anderson]

Ed,

This is a hard question to answer because there are so many variables. 

I would suggest that you set up single copy of mapserver on one 
computer, and use a performance testing program like JMeter 
(http://jakarta.apache.org/jmeter/) to simulate several concurrent 
users.  Keep adding to the concurrency until the average response time 
reaches the maximum you deem acceptable.  That should tell you how many 
requests one server can handle.  Do a little math to figure out how many 
computers you need for 2000 concurrent requests.

Keep in mind that there are many ways to improve the speed of 
Mapserver.  You'll probably want to do everything you can to squeeze 
performance out of your servers.  It would be a good idea to optimize 
Mapserver and your .map file before you do these calculations. 

Two thousand concurrent requests is a lot, so how you define 
"concurrent" makes a difference.  In my experience mapserver doesn't 
perform as well when it is hit with many requests at precisely the same 
instant, but if you distribute those requests over a short interval 
(even just 1-2 seconds), mapserver performs better.  That second case 
also tends to be more typical of a real application environment.  With 
JMeter you can "ramp up" your concurrent requests to help simulate this.

Good luck.

Brock

Ed Dowding wrote:

>This is a potentially endless question, but I'm setting up mapserver for a
>web app with large numbers of users (about 2,000 concurrent during peak
>activity).
>
>1. Any idea how many servers I'm going to need to meet this (at a guess,
>obviously - we'll do monitoring as the numbers rise)?
>
>2. What's the ideal spec and OS for mapserver in a production environment?
>Main questions are processors, RAM, and OS?
>
>
>Thanks in advance,
>
>Ed
>  
>