Hi,1. You have to start from metrics for your servers. Metrics from OS (cpu, memory, disk, network) and MySQL (grab 'show global status')2. Look at them, think :)I think - without information from the first paragraph, good start point will be increasing innodb_buffer_pool_size (for read access), and put log to another drive. It's, probably, most general things.Master-Master - is a complicated thing in a case of heavy writes (usually, solution is Galera - but there are lots limitations). Try to think about sharding or splitting business logic.