The web server must be built to fail to a known safe state if system initialization fails, shutdown fails, or aborts fail.

Determining a safe state for failure and weighing that against a potential DoS for users depends on what type of application the web server is hosting. For an application presenting publicly available information that is not critical, a safe state for failure might be to shut down for any type of failure; but for an application that presents critical and timely information, a shutdown might not be the best state for all failures. Performing a proper risk analysis of the hosted applications and configuring the web server according to what actions to take for each failure condition will provide a known fail safe state for the web server.