What i understand is, you have separate databases on client computer and you need to synchronize with central server database.
If you do not have changes in number of client or location of the client then you can update your central database that can update your client databases at that time. As we are using Linked server in MSSQL the similar way you can use MySQL FEDERATED Storage Engine
]. You can also use mirroring. But Please provide more information what can be suitagle on your scenario.