This hour provided you with information on Apache and operating system settings that can affect scalability and performance. In most cases, however, the problems in Web site scalability relate to dynamic content generation and database access. Hardware-related improvements, such as high-quality network cards and drivers, increased memory, and disk arrays can also provide enhanced performance.
With regard to virtual hosting, Apache can be configured to handle virtual hosts in a variety of ways. Whether you need a large number of cookie-cutter virtual hosts, a varied set of different virtual host configurations, or the number of IP addresses you can use is limited, there's a way to configure Apache for your application. Name-based virtual hosting is a common technique for deploying virtual hosts without using up IP addresses. IP-based virtual hosting is still necessary when a virtual host is used for SSL. If you cannot change your DNS configuration, your only recourse is to use separate port numbers for your virtual hosts.