Requirements for 2500 Concurrent Users

[jeffc31337]

We are planning on implementing vbulletin - Do you have any sorts of hardware requirement list you could send or post based on number of expected concurrent users?

We need to support 2500 concurrent users. Our current planned environment is 2 front end servers and one database server. Front ends dual pentium 4 with 2 gb of ram. Database server is a dual 3.2 ghz p4 with 8 gb of ram. Would that suffice?

[ManagerJosh]

There are really no set list of hardware recommendations simply because there are a lot of variables that determine stress load, ie: various attachments, how many options you turn on, etc.

[jeffc31337]

Thanks for the reponse. If anyone could give me feedback on a very bare bones message board install that would be helpful.(not many options) I guess my reponse would be a question to vbulletin: Do you guys have any kind of guidelines, or company contacts that could be queried, for commercial users who plan on using your software so that they can be sure to spec out hardware that is powerful enough?

[Reeve of Shinra]

There are a few people here with very busy sites that might able to share thier setups with you when they see this thread....

[ManagerJosh]

My suggestion is to see if you can get in touch with the people over at offtopic.com and see what sort of hardware setup they have

[VietLang]

If I were you I would use Opertons over Xeons because Opertons handle load much, and I mean MUCH, more than Xeons. When it comes to database queries, Operton has no match. Also get SCSI drives and put them in RAID and I think you'll be fine.

[George L]

As to your server requirements, there's a few things to note:

1. vB user online concurrently is based on default 15 min or 900 second cookie time out and is different from mysql concurrent connections ( max_connections/max_used_connections limit)

2. vB currently only can use mysql as a backend but later there will be ports to sybase and postgresql way after vB 3.x has been publicly released

3. MySQL regardless of forum software, provided it has the right hardware and mysql, php and apache configuration is good for theoretically 1000 - 1500 mysql concurrent connections (latter figure with the mysql rpm binaries) based on single dual cpu server setup (excluding dual, quad p4 xeons which could handle more)

4. this means you can have 1000 vB users online displayed but they actually can use 200 - 700 concurrent mysql max connections since vB shows those 1000 vB users over 15 mins / 900s and not the exact same second, you can have any combination

i.e.

300 members + 700 guests = 1000 vb users online past 15 min, with only 300 - 500 mysql concurrent connections in use

or

500 members + 500 guests = 1000 vb users online past 15min, with 500 - 800 mysql concurrent connections in use

both examples show 1,000 vb users online past 15mins but the latter example could place more load on the server due to more mysql concurrent connection usage

5. hardware isn't the only aspect which determines vB performance, you have to have apache, php and mysql configured optimally - left unoptimised especially mysql's configuration, then even the most powerful hardware will not perform well

6. if you set your vB timeout cookie higher than default 15 mins, you will show more vB users online - so set timeout cookie in vB admin panel to 30 mins, then the vB user online display will show users on in the past 30 mins thereby inflating the vB user online display - generally the higher the cookie timeout, the higher the vB users online to mysql concurrent connections ratio

So really what hardware to recommend would largerly be determined by what that 2,500 concurrent users are made up of.

2,500 concurrent users over 3600 seconds duration is alot different in terms of server load

versus

2,500 concurrent users over 900 seconds duration

1. Do you currently have a forum running ? what software and is their a similar cookie timeout of value used to determine/display concurrent user numbers online ?

2. if you have current server/forum providing a few answers where relevant to questions asked at http://www.vbulletin.com/forum/showthread.php?t=70117 would help us help you recommend a server(s) setup. Particular mysqladmin extended-status output on your database server

Assuming that 2,500 vB users is over default vB 900s cookie timeout, you'd probably be generating around 600-900+ mysql concurrent connections on mysql database server. Based on this guestimate, I would recommend optimally the following configuration to start off with:

web server:
AMD Athlon64 Dual Opteron 250 or 252 cpus
4GB Registered ECC DDR400 memory
10,000rpm SCSI disks size as determined by your storage requirements
dual gigabit network cards

you can plug the web server into a hardware load balancer, and plug more web servers in later if needed - however currently with attachments in filesystem option you will run into a problem with load balanced web servers. vB developers are working on fixing this. However, if you have attachemnts in database option enabled then no problems however database loads will be alot more. If you don't intend to enable attachments in posts then you can disable them if you use web servers load balanced.

mysql database server:
AMD Athlon64 Dual Opteron 250 or 252 cpus
8GB Registered ECC DDR400 memory
2x 18GB 15,000rpm SCSI disks raid 0 - place vB's postindex and word tables on this disk and use symlink to the mysql data partition i.e. /var/lib/mysql/databasename
4x 36GB 15,000rpm SCSI disk raid 10 - the default location for mysql database data partition i.e. /var/lib/mysql/databasename
use hardware SCSI raid controller with onboard cpu and 256MB cache
dual gigabit network cards

use

lastest stable 2.6.x smp linux kernel
Apache 2.0.54 compiled as prefork mpm worker
PHP 4.4.0
MySQL 4.0.26 rpm binary for handling more concurrent users
Eaccelerator or APC cache - right now only APC cache works with 64bit linux OSes)

Linux flavour for AMD64 Opterons best is Suse Enterprise linux 64bit OS

NB. Dual AMD64 Opterons even in speeds 244-246 are 25-50% faster and better at handling more apache and mysql concurrent connections than Dual P4 3.2-3.6Ghz xeons. So Dual AMD64 Opteron 250-252 cpus should be much better