Improve sentry cache (server, client) by using a stable commercial or main-strain cache

We've seen many unreproducible issues because the sentry caches (either server side or client/plugin side) are full, or out of sync; We could start to consider a main-stream or open source cache to use across sentry project. The benefit of a widely used cache system:

1. has basic monitoring or dump facility;
2. has useful logging system;
3. usually is very high performanced in the memory;

I know for example, kafka incorporate RocksDb (code example).