I am offering forums [phpBB] with my new hosting venture. My concern-- the number of users allowed to access client boards at any given time.

In most cases-- those installing the forum will not be a problem because a community is hard to start-- however I am wondering what your experience has been in this area.

Q...

Are you managing the entire dedicated server yourself? You may want to add a clause about CPU/memory usage in your terms of service.

I would definately monitor them, along with all the other services, and tweak as you go along. For the most part you won't have too much of a problem starting out.

PHPBB isn't too bad but there's some forum software which is just poorly coded, leaving your server on its knees or with such a high load that its not useful to anyone else during that time. You should really spend the time to make sure all the tweaks are in place and consider a cluster of database servers behind the scenes to handle the demands that may be incurred. Remember even if no forum individually is popular, in aggregate a couple hundred small-traffic forums can add it up to a lot of cpu usage.

Limit the number of mysql connections.

Limiting mysql connections will error out for him if he uses that method. Thus some visitors may not be able to visit when mysql resources are boggled up.

If you see that your site is receiving more traffic and is sustainable a RAM upgrade usually works in this case. Simply optimized the MySql accordingly to utilize the new memory insertion. Therefore, it should be scalable up to the part where there is a hardware limit on the RAM it can be installed.

You can limit the connections by user. So if any one of his clients is using an excessive amount, you'd probably want them to error out so that they can either 1.) make their code more efficient 2.) upgrade to a better account 3.) not degrade everyone else's utilization

I am not sure I can limit the number of MySQL connections per account-- checking into it. Thanks for all the great advice.

Q...

if you are selling strictly applications, undersell your CPU and RAM and you will not have a problem.

Limiting mysql connections is typically done when a host is oversold and is trying to limit a user to only utilizing their bandwith for static traffic - or mostly static traffic.

An alternate to limiting mysql connections is to sell reasonable packages which will allow a user to utilize all of the bandwidth they have purchased towards mysql traffic without exceeding CPU/RAM limits of the server.

Just watch your CPU resource use. Also, be very aware that phpbb is heavily targeted by automated spammers and hackers.