Major Description
Currently, the configuration cache relies on not_my_vbucket responses as an indicator that the configuration needs to be updated. In an environment with memcached buckets only though, there will not be such a response and thus we need another way to reliably update the configuration.
One thought would be to simply ensure the configuration cache is not more than NN seconds old. The process who has the configuration connection would simply need to touch it every NN-1 seconds if the configuration connection is still active.
If that process exits, then after NN seconds, processes will race to create a new configuration cache file.
The only downside I can see is that certain failure modes (stale TCP socket) would still need to be handled.