Problem about Master - Master replication and lost connection

Good morning,

I configure a 3 node Percona XtraDB Cluster and everything was working smoothly apparently. I will describe my current architecture. I have 3 servers, 2 servers are being used by the clients in two different locations and the client’s applications connect directly (locally) to the each server database and the 3rd server is in another location and is only use with backup purposes. But we want all server’s databases to be in sync even if is eventually we don’t need real time sync.

The problem challenge here is that my client’s locations doesn’t have constant internet connection. Most of the time the nodes get disconnected and when the nodes are back online they don’t reconnect to the cluster and if I restart MySQL the node gets SST with the state of the 3rd node and I loose the data on the disconnected node.

What should I do? Do you any recommendations? Because we’re going to add more nodes and this is going to be a mess.

Thanks in advanced.