Orange = requests/sec; black = memory used; red = % time spent in gc; blue = median msec to serve an item page; green = median msec to serve the frontpage. The last two are unnaturally spiky because I use a very narrow window (because we use the same data to to drive our Leftronic screen at YC). So the blue spikes don't represent anything that would have been observable to users.
The slowly rising gc percentage (red) is a sign of memory leaks. They used to be a lot worse before Rtm finally tracked down the main culprit this summer.
We're now getting a bit over 900k page views per day.