Hello,

I'm new to this forum, and quite new to Linux, with main background / skills in database design and SQL optimization. I moved over from the "other" side a few months ago after quiting my job, and have had my head burried in linux, apache, php, mysql all summer. Found lots of good stuff on this site by the way. Thanks to all...

I'm creating my own business and have started developing an Application Service Provider model for real estate agencies where I live, in the south of France. I wanted to see if anyone had experience with this type of ASP setup, and particularly with hardware reqs and performance for linux based systems.

I recently had an opportunity to get a really good deal on 3 racks at a corporate bankruptcy auction, and seized it. The current config on the boxes is:

-no.1 : 2U - dual Xeon 2.8Ghz, 2Gb ECC DDR RAM, 5 x 18Gb SCSI U160 with zero-channel RAID adaptec card
-no.2 : 1U - dual P3 1.13Ghz, 1Gb ECC SDRAM, 2 x 18Gb SCSI U160
-no.3 : 1U - single P4 1.8 Ghz, 1Gb DDR RAM, 1 x 60 Gb IDE

I am planning tu run everything off Suse Enterprise 8 (bought the box to get the support services), Apache 1.3.28, and recent production releases of PHP and MySql (with InnoDB) 4.x.x. I will also need to run firewall, mail server, and primary & backup DNS.

In any case, to help size the requirements, here is some info about the application itself and its users:

The app will basically have 2 sides: 1) admin side: record new properties, upload photos, manage clients, sales follow-through management, rentals management...etc. 2) The public side will basically enable visitors to browse properties selected for public site publishing by the client.

So this will be very database intensive. The public web sites will mostly rely on dynamically generated html pages / cron processes running every night, but the admin extranets will have to be real time data, as it will be a critical sales / business application.

This will also be heavy on includes and conditional processing at PHP runtime. To make maintenance and upgrades manageable, all the sites will have to use the same core application modules from a common directory (both for admin and public sides). Everything else that is client specific (graphics, html header / footer, conf files, style sheets, company specific content pages...) will be configured and included from a separate directory, whose name will be based on each client's domain name.

From market research, it appears that the average agency will have 3-5 office users (note: "real", not forwarded, e-mail addresses for all users will be part of the package). They will be using the admin system on an ongoing basis, especially salespeople who will run property searches, enter contact information, follow-up notes and callback dates each time they speak with a prospect. Number of dynamic pages viewed on the admin side is estimated at 1000-2000 pages per day per client (meaning per agency =>for all 3-5 users), each involving an average of 1-3 SQL queries (with a fairly even distribution over insert, update and select statements). Public web site traffic for each client will be quite small and estimated at roughly 1000 pages per day per agency.

We'll round this to an average 2500 pages per client per day, with 65% database intensive and 35% static html.

I have 4 questions:

1) Does the hardware I bought sound appropriate ? Not enough ? Over-kill ?

2) if OK, which machine for what ? I was thinking of no.1 (dual xeon) dedicated to mysql, no.2 (dual P3) running apache / php and also acting as backup DNS server, and no.3 (single P4) running firewall, primary dns and mail. Would you do it differently ? how ? any other recommendations (not necessarily about hardware) ?

3) this is a really tough call, even with the information I provided above... there are just so many parameters.... But, speaking from intuition and experience, and with the above information, and assuming the SQL and indexes will be properly optimized, how many clients do you think I can safely host until the hardware starts choking ? roughly 25 ? (100 office users, + 20,000 static web page views) more around 100 (400 office users and 80,000 static page views ) ? more ? less ? Any educated guesses / ball park figures are welcome...

4) Any specific recommendations or cautions you would offer for such an app. service provider model (anything really, related from apache to php codign advice or dns setup) ?

Many thanks in advance...