It is easy to purchase several servers and then to run some Node processes on them. However, how can those distinct servers be coordinated such that they form part of a single application? One aspect of this problem concerns clustering multiple identical servers around a single entry point. How can client connections be shared across a pool of servers?
Horizontal scaling is the process of splitting up your architecture into network-distinct nodes and coordinating them. Cloud computing relates here, and simply means locating some of the functionality an application running on a server somewhere on a remote server, running somewhere else. Without a single point of failure (so the theory goes) the general system is more robust. The parking lot problem is another consideration that Walmart likely faces—during shopping holidays, you will need many...