Strange memcached behavior on stress test

[Steven Grimm]

 > We restart it daily.

We, on the other hand, never restart it, and we transfer way more than 
64GB of data with no signs of instability. I just looked at one of our 
memcached instances and it has these stats (commas added for readability):

STAT bytes_read 204,016,350,632
STAT bytes_written 11,728,604,145,226

Here's another one that serves more volatile data (bigger ratio of 
writes to reads):

STAT bytes_read 2,606,059,831,972
STAT bytes_written 8,071,661,999,891

This is after about 30 days of uptime. We only restart memcached when we 
make configuration or code changes; it is rock solid other than that.

Caveat: We are, as you might expect, running the Facebook code, not the 
stock 1.1.12 code. So it's possible some of the changes we made had the 
side effect of fixing whatever problem you're running into.

-Steve