The thing that kills you is IOPs per query. At 30 TBs the hot data set is huge an there is a long tail of queries not loaded into memory. Plus they were sayin

The thing that kills you is IOPs per query. At 30 TBs the hot data set is huge an there is a long tail of queries not loaded into memory. Plus they were saying 10k+ connections per server. So we are probably looking st 500k+ connections. There is also a regular influx on unoptimized / badly written queries as people add features/games etc. Plus you can end up with random spikes. This setup is likely optimized for high read availability. The slides mention the mental overhead of failovers. This is a thing. Try to explain and help each team understand how to do those safely. Downtime are also not an option. So there is quite some information and context (likely) missing. I used to manage a similar scale zoo of MySQL (similar peak QPS, less total data iirc). I am not sure I would subscribe so much on the Vitess as solution side though. Galera and Group Replication can give you hassle free failovers, add some read replicas and you have a really nice DB setup that can scale horizontally amd vertically until you hit the write limitations per server.