We saw in Chapter 2, Understanding Layer 2, 3, and 4 Protocols , what information is available at each of the layers defined by the OSI Seven Layer Model, from basic Ethernet and IP addressing information used by traditional Layer 2 and 3 switches, to identification of protocols and applications at Layer 4. Layer 7 server load balancing, along with other Layer 7 applications such as Web cache redirection, raises the stakes once more by examining information being generated by the application itself. This could be anything from the URL the user is requesting, the name of the video the user wants to watch, or even the name being requested in a DNS request. Typical applications of Layer 7 server load balancing, which we will look at in more detail later, are:
In general, Layer 7 server load balancing enhances the user experience by making best use of the available resources. |