A couple weeks ago I moved my vBulletin boards which usually have about 20-40 users online at the same time to onefusion's Fusion Prime reseller account. Within a day we were having speed problems, with scripts taking a long time to execute and files not being served very fast. Then came server crashes..after the server load would hit 5+ with only 20 people online...once we got it up to 186 somehow..with only 30 people online. They asked us to reduce the load once, and after taking measures to do so I found our account suspended without notice the next day. Took me an entire weekend to get the files from my site back in my hands.

Two thumbs down.

Did you have Persistant Connections enabled or disabled in the config.php?

Disabled.

Are you on a shared server?
Do you have gzip enabled?
Do you allow binaries be posted (via attachements or avatars) on yoru board? What are the limits you have imposed on these?

You're not giving the whole details.

And if you're running into connection problems visit http://www.vbulletin.com/
They've seen it all

You need to provide:
1. your server information
2. Mysql version
3. PHP version
4. Shared server or not.
5. persistent connections on or off in your config file. etc

Are you on a shared server?

Yes, as I am on my new host, which has had no problems with me.


Do you have gzip enabled?

Yes. I would've disabled it but they took forever to install mod_gzip, and when they did, they didn't inform me.

Do you allow binaries be posted (via attachements or avatars) on yoru board? What are the limits you have imposed on these?

Yes, limits are 50K on attachments and 10K on avatars. This is the same on my new host, with no problems.

I posted on vBulletin's forums, tried what they suggested, but after a few days I couldn't try their suggestions anymore, as my account had been suspended.

Persistent connections Disabled? You're crazy! :)

Enable them and ask the host to optimize their PHP and mySQL settings. This'll drop your forum's mySQL load down exponentially.

Trust me on this one. The overhead for establishing a new mySQL connection each and every time someone views a page is what's killing your connection. RackNine's website (http://www.racknine.com) Is completely php/mysql driven, sometimes receiving hundreds of queries per minute. Without persistent connections server load for the main site and subdomains would be way higher.

Sincerely,

-Matt

You sure? The way I've always heard it is that persistant connections increase the load...

Yeah, even when talking to one of the support staff at vbulletin he told me having persistant connections on increases the server load and that he recommends to turn them off...

Not for popular sites that have constant connections to mysql. Consider this:

The most resource intensive part of a fast-loading page that uses mySQL is the connection to a database.
Persistent connections remove the connecting part. PHP simply looks for an already open connection using the same resource and attaches you to it. Very-very fast.
Popular forums make 10-20 mysql connection every time a single user loads a page (user authentication, cookie session, forum threads, forum index, searches, etc.)

Yes, too many persistent connections can kill a host if they haven't set mysql up properly. Explain to your host their resource use will go down exponentially if they allow a considerable number of persistant mySQL connections with low timeout period for the connections. You'll need to be root and modify PHP.INI and MY.CNF to do this. You can drop the sql resource use by 75-95% with a properly configured set of persistent connections.

Feel free to email me if you have further questions: mmeier@racknine.com

Sincerely,

-Matt