I colocate a server for a busy forum using UBBThreads 6.3.2.
Ever since the upgrade to 6.3.2 the server has been crashing quite a bit once we get 80+ users viewing the forums at the same time, the load shoots through the roof and its a downward spiral from there. I've got to shutdown mysql and restart it to get back to normal. Sometimes when this happens the w3t_Posts column get corrupted and I've got to myisamchk -o it to get back to normal.

The current server is running Mandrake with latest kernel. Mysql version is 4.0.17, and mysql is tuned as best as it can be for the 512Megs of RAM we have still leaving room for apache. At busy periods mem will start to swap and things get ugly with load.
This forum currently has 12000 active users and it is climbing. Right now specs are a 1Ghz Pentium III and 512M of RAM. I know we need more RAM for Mysql, but the motherboard is a socket 370 and won't support throwing in another Gig of RAM, so it looks like either scouring for a new motherboard that will support 1.5Gig to use with the current hardware(which is not an easy find) or upgrading the server.

I would like to get some opinions about hardware specs for supporting a large number of users leaving room for growth or some ideas of how to tune what we have better. Any help would be appreciated.

What's the URL to your board?

Have you installed any of the various PHP accelerators/compilers/caches?

You've also pretty much answered your own question above... you probably need more memory, but as your server can't be expanded any further, it's time to look at a new one. You might also consider buying a second box just to host the database, if you can afford to do so with your host.

the board url is www.knifeforums.com

I host the box for him so hosting issues etc dont really matter , I'm trying to get information about what kind of specs he needs in a new server to forward to him. I don't have any kind of PHP compilers etc installed.

I want to point him in the direction of something that will handle his current users plus leave room for growth, but I also don't want take a huge dent out of his wallet. What kind of hardware are most people using with a board with around the same number of members?

Won't that motherboard hold an even 1 gig or RAM? If so, moving from 512 to 1 gig will make a large difference.

no go, its a slot 370 with 3 PC133 dimm slots. I tried putting 3 512 chips in it and it won't recognize anything over the initial 512.

Mmm. The board has about 300,000 messages.

I'm hosting a Threads with ~400,000 messages on a single P4 2.0Ghz with 1.5 gigs of memory, and a single 7200 RPM IDE drive.

We get about 120,000 new messages posted every month (~4,000 a day), with ~4 million monthly script pageviews. The database is kept pruned to its current size to prevent killing the server... load averages around 4-6 during peak hours.

It isn't screaming fast all the time, but it isn't slow enough for anyone to complain. A PHP accelerator is a key part of keeping the server happy.

Now, let's put things in perspective. While the database sizes are nearly the same, there are "only" ~300 new posts in the past 24 hours on the board, and "only" 100 people online in a 10 minute window.

The board and MySQL should be quite happy on similar commodity hardware and lots of memory. 2 gigs or so. You can probably put together an 'entry-level' ~2GHz system for $500 or so that could later be expanded to use a faster processor or SCSI drives if the need is present.

The key thing is going to be the memory for MySQL. The more memory it can use, the less it will have to go do disk. The less it goes to disk, the faster things perform.

As a general rule, of course.

Thanks for the advice. Just wanted to get a general idea of the hardware people are using for this size of forum.

[]Brandon Long said:
no go, its a slot 370 with 3 PC133 dimm slots. I tried putting 3 512 chips in it and it won't recognize anything over the initial 512. [/]
Maybe the current RAM is PC100 rather than PC133?
Many boards don't recognize the PC133 RAM if there is a PC100 dimm in the first slot.

From my experience, 1GB of Ram should be sufficient for this kind of board.
Maybe you can put up a log file that keeps track of the slow queries and the number of searches that are done.
Searches are the bottleneck. So if the users do many searches/several at the same time it might get slow again.

Hi Charles
What board are you talking about? Can you give me the url? I would like to see how this software operates with a board that size.

My Little board crashes with 100 visitors almost like clock work.

Thanks for the help

http://www.trekbbs.com/threads/ubbthreads.php

There are a couple custom modifications in play, including user post count group access, a comprehensive floodcheck for unregistered user pageviews (to encourage users to register and post), some minor layout and CSS tweaks, and more.

The juicier forums are available only to registered members.

[]Have you installed any of the various PHP accelerators/compilers/caches? [/]
Haven't heard of these, could you give some more info?

Sure.

PHP, like most modern scripting languages (Perl, Python, etc), uses a variant on a virtual machine, like Java and MS's .NET.

When you visit a PHP script, PHP will parse the script, turn it into bytecode, then run the bytecode on its own internal engine.

Bytecode caches intercept that process. If the script you're visiting has already been compiled, the compiled bytecode is loaded instantly, either from an in-memory or on-disk cache. Most caches will also try to optimize the compiled bytecode.

The end result is much faster PHP speeds.

There are really only two options available nowadays:

- The Zend Optimizer, by the company that makes PHP itself: http://www.zend.com/store/products/zend-optimizer.php

- The Turck MMCache, which is so good that the guy behind it was hired by Zend: http://turck-mmcache.sourceforge.net/

There were a few more players in the market, but they seem to no longer be updated and only work with really old PHPs.

Installing and properly configuring one of these caches can result in really dramatic performance improvement...

Cool, I will check those out.