Red Hat ENTERPRISE LINUX 3 Reference Manual

Also see for ENTERPRISE LINUX 3 - SECURITY GUIDE: Tuning guide Installation guide Installation guide Installation guide Manual

Contents

146 Chapter 10. Apache HTTP Server10.5.32. DefaultTypeDefaultType sets a default content type for the Web server to use for documents whose MIME typescannot be determined. The default is text/plain.10.5.33. HostnameLookupsHostnameLookups can be set to on, off or double. If HostnameLookups is set to on, the server au-tomatically resolves the IP address for each connection. Resolving the IP address means that the servermakes one or more connections to a DNS server, adding processing overhead. If HostnameLookupsis set to double, the server performs a double-reverse DNS look up adding even more processingoverhead.To conserve resources on the server, HostnameLookups is set to off by default.If hostnames are required in server log files, consider running one of the many log analyzer tools thatperform the DNS lookups more efficiently and in bulk when rotating the Web server log files.10.5.34. ErrorLogErrorLog specifies the file where server errors are logged. By default, this directive is set to/var/log/httpd/error_log.10.5.35. LogLevelLogLevel sets how verbose the error messages in the error logs are. LogLevel can be set (fromleast verbose to most verbose) to emerg, alert, crit, error, warn, notice, info or debug. Thedefault LogLevel is warn.10.5.36. LogFormatThe LogFormat directive configures the format of the various Web server log files. The actualLogFormat used depends on the settings given in the CustomLog directive (refer to Section 10.5.37CustomLog).The following are the format options if the CustomLog directive is set to combined:%h (remote host’s IP address or hostname)Lists the remote IP address of the requesting client. If HostnameLookups is set to on, the clienthostname is recorded unless it is not available from DNS.%l (rfc931)Not used. A hyphen [-] appears in the log file for this field.%u (authenticated user)If authentication was required, lists the user name of the user is recorded. Usually, this is notused, so a hyphen [-] appears in the log file for this field.%t (date)Lists the date and time of the request.