SafeKit N-to-1 architecture

Shared backup for multiple active servers

With a basic mirror architecture, based on a primary server and a dedicated backup server, the backup server is inactive, and just waits for the failure of the primary server in order to restart the application.

If you deploy multiple basic mirror clusters, you need as many backups as there are primary servers (3 mirrors means 3 backup servers).

With the SafeKit multi-modules feature, you can designate a single physical backup server as backup server for all the primary servers. This is an N-to-1 architecture, with N primary servers and one backup server.

If one of the N active servers fails, the single backup server restarts the module of the failed server.

You can configure SafeKit to automatically return to the primary server once the problem is fixed and the failed server restarts, or you can switch back to the primary server manually.

Unlike the mutual takeover architecture, the backup server doesn't have to handle a double workload when a primary server fails. This assumes there is only one failure at a time—the solution can support multiple primary server failures at the same time, but in this case the single back-up server will have to handle the combined workload of all the failed servers.

The mutual takeover architecture requires the SafeKit multi-module feature.