You can't optimize anything with C++ if your database is stuck waiting for consensus with nodes 100 ms away. Close to the metal and low level languages are really poor choices here, even Go is too low level for CP databases.
Yes, but you'll have lower overhead on each query/request and more concurrency ? For each query the bottleneck is the network which you can't fix, but you can fix the 2,3,etc bottlenecks which are inside 1 machine (cpu/ram/disk).
Yeah...I'm not really aware of a higher level language that mystically makes networking faster. As far as I'm aware, the most efficient network protocols tend to be implemented at a low level, too.
