The web server may host applications that display information that cannot be disrupted, such as information that is time-critical or life-threatening. In these cases, a web server that shuts down or ceases to be accessible when there is a failure is not acceptable. In these types of cases, clustering of web servers is used. Clustering of multiple web servers is a common approach to providing fail-safe application availability. To assure application availability, the web server must provide clustering or some form of failover functionality.
Review the web server documentation, deployed configuration, and risk analysis documentation to verify that the web server is configured to provide clustering functionality, if the web server is a high-availability web server. If the web server is not a high-availability web server, this finding is NA. If the web server is not configured to provide clustering or some form of failover functionality and the web server is a high-availability server, this is a finding.
Configure the web server to provide application failover, or participate in a web cluster that provides failover for high-availability web servers.