As you may have already discovered if you've visited the forums since this morning, they've been inaccessible for a few hours. While we're still investigating the cause, a brief synopsis is as follows.
At some point around 9:30am MDT, several processes began triggering the OOM (Out-of-Memory) killer. This rarely happens except in circumstances of high loads and only when all available virtual memory (including swap) is exhausted. While not ideal, it is a solution that attempts to kill off the highest memory-consuming processes on the machine in effort to recover it to a point where it can continue running. Unfortunately, because the OOM-killer uses SIGKILL (kill the process immediately), killed processes aren't given a chance to shut down gracefully. This is by design: Systems that have encountered an out-of-memory condition won't have sufficient memory available for the killed processes to allocate what they might need during shutdown.
Because of this and because of the OOM-killer's selection of processes, the MySQL database process (which powers the forums and some of the other 'goon sites) was selected for termination. MySQL may have been in a write state at the time, because several tables were corrupted and the server left unable to start. This has required me to restore the database from a mix of backups and MySQL's binary logs. As a result, some posts between September 4th and 5th of last year and anything posted after 8:00am MDT this morning (July 18th) may be missing from the restoration process. I apologize if your post is one of the missing ones.
Initial investigation suggests that something was triggering a very rapid spawn of httpd processes which could be synonymous with a huge traffic spike. The source of that spike is yet unknown as I haven't had much of a chance to examine the logs. Moreover, since syslog was one of the processes selected at random for termination, any logging data that wasn't buffered by the kernel (which basically means anything that wasn't part of the kernel log) hasn't been stored.
I'll keep you posted.