Ability to log changes to pools (such as server ejections or re-adds) without enabling extremely verbose logging

Is your feature request related to a problem? Please describe. I would like to know when memcached servers go down and get ejected from the twemproxy pools, and when they get re-added, but without seeing log lines for every memcached get request which would be in millions per minute for us.

Describe the solution you'd like Logging of ejections and re-adds at a verbosity level below one that prints every memcached get request. I think that would means verbosity level < 5.

Describe alternatives you've considered Tried various verbosity levels and with-debug compilation levels, but no solution was found.