I was interested to hear about semi-sync replication improvements in MySQL’s 5.7.4 DMR release and decided to check it out. I previously blogged about poor semi-sync performance and was pretty disappointed from semi-sync’s performance across WAN distances back then, particularly with many client threads.
The basic environment of these tests was:
- AWS EC2 m3.medium instances
- Master in us-east-1, slave in us-west-1 …