What load can vBulletin handle?

[interested_cust]

I am researching message board products and need to know if vBulletin can handle up to 1500 concurrent users at a peak time and a million page views in one day. What is the most one server (like a dual proc, 1gig of ram, maybe a fast ide drive or scsi drive) can handle?

[eva2000]

remember a few things

1. vB user online concurrently is based on default 15 min cookie and is different from mysql concurrent connections
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, 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)
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 and not the exact same sec, 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

with the above points for 1 vB installed and no other site sharing the server:

a single dual cpu server running Red Hat 7.3, latest 2.4.x smp stable kernel, PHP 4.2.3 compiled with zlib support and compiled to use MySQL client libraries instead of PHP's own included mysql libraries, MySQL 3.23.52 installed from rpm binary, Apache 1.3.26

with properly fine tuned mysql, apache and php settings

Dual P3 1.4ghz Tualatin
2GB REG ECC PC2100 DDRAM
4 x 36GB 15,000 rpm SCSI raid 0+1
with 2 x 10/100 NICs

would probably handle anyware between 400 - 800 vB users online or around 350 - 550 mysql concurrent connections

however if you intend to have consistently 1,500 vB users online and 1+ m pageviews/day then you will definitely need a 2 server setup

1 server as a dedicated web server
1 server as a dedicated mysql database server

i.e. 2 of these

Dual P3 1.4ghz Tualatin
2GB REG ECC PC2100 DDRAM
4 x 36GB 15,000 rpm SCSI raid 0+1
with 2 x 10/100 NICs

database server may need 2 - 3GB memory

Note this is all just theory and based on my observations and with working with various large vB clients which have >1,000 vB users online - generally these larger vBs have a 2:1 or 3:1 or higher vB user to mysql concurrent connection ratio - so really 1,000 vB users only use around 200 - 600 mysql concureent connections

i've seen a few vB's with close to 800 - 990 mysql concurrent connections displaying 1,200 - 1,400 vB users online as well (these vBs are all on 2 server setups dedicated web and database servers)

http://forums.fanhome.com is a vB forum ported by the owner to use sybase database which should on the whole be able to support more concurrent connections that mysql database backend

the same goes for using postgresql database backend

both of these backends will eventually make it to vB well after vB 3.x release which is a few months away right now

hope that helps :)