Guest Limits?
 

I am outgrowing my server, which is crazy for me. It's a Dual Xeon with plenty of power but it is not uncommon for me to have 150-200 members and 450 guests on at a time.

Anyway, mysql keeps bombing. I get tons of mysql can't connect error emails.

Is there any code out there for limiting the amount of guests that can be on at a time? Or should I look at tuning my server? Any suggestions are appreciated.

remove unwanted addons in case you have them, which takes up huge server loads... (should help you a lot)

have you checked how many of those 450 guests are real guests and/or spiders ?
I will recommend setting up a crawl delay for yahoo slurp spider in your robots.txt

this should help..

Going through add-ons now and making some decisions. I also changed some of my board options, like similar threads and threadview updates, etc.

As for crawl delay...I don't want to sound like a bonehead, but how much of a delay?

<a href="http://www.vbulletin.com/robots.txt" target="_blank">http://www.vbulletin.com/robots.txt</a>

how many yahoo slurp spdiers do you find online (kindly mention cookie timeout if possible)

45 minutes per member requests. And I have 192 Yahoo slurps on right now. I set the delay to 20 secs for now.