I have been trying to figure this out the past couple of weeks. We used to have a five-host Percona cluster at different providers. When it started acting up I read that it is a bad idea to have synchronous replication across data centers. Now we have a three-node cluster in one data center and it is stable.
I am trying to figure out the best way to have data center redundancy.
I read that you can have two individual clusters, one in each data center and have an async link between them. Upon further reading though it seems that it is typically for a DR scenario so the slave cluster is not utilized and while the fail over is easy, the fall back is a bit involved.
I am very new to DB clustering, I am hoping for guidance. The database clients will be using HAProxy, and will only point to the hosts in one datacenter.
I am hoping that I can split the clients half to each DC and have the async link replicate the data across. How would you guys do this? What is everyone using these days?