The Node.js cluster module is a common method of scaling servers, allowing for the use of all available CPU cores. However, what happens when you must scale to multiple servers or virtual machines?
That is the problem we faced when scaling our newest HTML5 MMORPG. Rather than trying to cluster on a single machine, we wanted to get the benefit of a truly distributed system that can automatically failover and spread the load across multiple servers and even data-centers.
Via Jan Hesse