Best Pratices for this scenario

Hi everybody and please forgive my english.

I’ve got a 4 server cluster working on a local network environment, everything works like a charm.

Now I’d like to add a new cluster outter the office (WAN). I can only connect the wan cluster to one of the lan cluster (the port listener). So, how could i do that?

Could i add the wan server to the lan cluster adding only two gcomm urls? (wsrep_cluster_address = gcomm://{wan_ip_of_local_cluster},{wan_ip_of_external_server} (I don’t think quorum will deal with this)

Could i create a second my.cnf on local_lan_server configuring a second cluster with only those 2 nodes? (is there anyway to know if both of them are synched?)

Is there any other way?

I would really apreciate some light with this.

Thanks in advance

How many servers do you have in second place?
As I understand you can look on this scheme: [first cluster] <----master/slave replication-----> [second cluster].
But if you are going to write in both clusters and connection between them is down you will be in trouble.

Thank you for your answer sergeym . There’s only one machine in the second place ( an VPS machine) i will only use it if all my office goes down (changing the DNS A record) to ensure minimal service to the application users until office come back. So, both “systems” will never be accesible from the users simultaneously.

I thought about adding the external machine to the cluster becouse of the “transparent” sync when office came back.

What really scare me in a master → slave replication mode is hot resyncing the LAN cluster with the WAN machine.