Loadbalancer tuning

[alierak]

I'm going to restart Varnish on the main loadbalancer at 8am CDT (13:00 UTC). Dreamwidth will be completely unavailable for a very brief time, and then maybe a little slower for a while as the cache gets refilled. But when it's done, some things should be faster than they are now. Since we have new servers with more RAM, it's time to use some of it to cache more user icons.