Chapter 8. Scaling Your Application

	Evolution is a process of constant branching and expansion.
	--Stephen Jay Gould

Scalability and performance are not the same thing:

	The terms "performance" and "scalability" are commonly used interchangeably, but the two are distinct: performance measures the speed with which a single request can be executed, while scalability measures the ability of a request to maintain its performance under increasing load. For example, the performance of a request may be reported as generating a valid response within three seconds, but the scalability of the request measures the request's ability to maintain that three-second response time as the user load increases.
	--Steven Haines, "Pro Java EE 5"

In the previous chapter we looked at how Node clusters might be used to increase the performance of an application. Through the use of clusters of processes and workers we've learned how to efficiently deliver results in the face of many simultaneous requests. We learned...