Link is dead or down, I can't wait to read this!
Apache-specific advice: if you're on a small VPS or other box with not much RAM, and didn't tweak the distribution defaults for MaxClients and friends in its configuration, a HN-size load will OOM you rapidly, especially with mod_php. The defaults for prefork MPM are nuts in the major distros (as in, assuming 4 GB of RAM or more for mod_php).
Since you're going up and down, I assume this is the case. I suggest dropping MaxClients to 5 for now and letting us wait a bit.
I dropped down the number of preforked apache processes, we'll see if that helps. It's also where i run some rails experiments, so we'll see. Load's back up to 7...
I had no idea hacker news got a lot of traffic.