Rate per second stats are not correct are misguiding.

[arunk2]

We are extensively use phpmemcachedadmin for optimizing our cache layer. and found the 'Rate' of hits, misses, evictions are not real time things. And found the code calculation it with the formula of 'total no.of activities' (hits/misses/evictions...) / time from the start of system.

Though the formula is kind of technically right. It doesn't give the realtime rates. Ideally it should be for a window of time period (like last 1 hour or 1 day).
We spent lot of time in debugging this issue and observed the root cause. We were tuning our application and not seeing the change in Stats.