I have a web application that runs on an a main server.
The same application also runs on multiple offline servers. These offline servers are not technically offline all the times but the internet connection is unreliable.
Whenever internet becomes available at any of the offline servers, I would like to sync its data with the main server. The data syncing will be two way, changes from the main server will go to the offline server and vice versa.
I am looking at MySQL replication and it would work seamlessly if it was just one main server and one offline server, but since there can be multiple offline server, I am thinking what is the best way to proceed.