Yerxa Most animals in the wild learn to adapt to their environments almost immediately after birth, or risk death. Similarly, Web sites must be continuously updated if they are to thrive. The initial decisions you make about updating and expanding your site will directly affect its efficiency as well as its performance. The structure of your Web site determines how you propagate content changes to your Web servers.
Sites grow too large too fast for single-server solutions.
The integration of additional servers into a single homogenous Web site is fundamental to a content-replication strategic design. For example, a site with two servers would have a DNS record containing two IP addresses, a.b.c.d and a.b.c.e. Clients who visit your site resolve the URL to the site's DNS record. Conversely, subsequent DNS queries may or may not return the same IP addresses in the same order. As a result, Web surfers are not guaranteed which IP their browser will access.