Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual page 366

Chapter 22. Apache HTTP Server
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 client
hostname 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)
Lists the username of the user recorded if authentication was required. Usually, this is not used,
so a hyphen - appears in the log file for this field.
%t (date)
Lists the date and time of the request.
%r (request string)
Lists the request string exactly as it came from the browser or client.
%s (status)
Lists the HTTP status code which was returned to the client host.
%b (bytes)
Lists the size of the document.
%\"%{Referer}i\" (referrer)
Lists the URL of the webpage which referred the client host to Web server.
%\"%{User-Agent}i\" (user-agent)
Lists the type of Web browser making the request.
LogLevel
LogLevel sets how verbose the error messages in the error logs are. LogLevel can be set (from
least verbose to most verbose) to emerg, alert, crit, error, warn, notice, info, or debug. The
default LogLevel is warn.
MaxKeepAliveRequests
This directive sets the maximum number of requests allowed per persistent connection.
The Apache Project recommends a high setting, which improves the server's performance.
MaxKeepAliveRequests is set to 100 by default, which should be appropriate for most situations.
NameVirtualHost
The NameVirtualHost directive associates an IP address and port number, if necessary, for any
name-based virtual hosts. Name-based virtual hosting allows one Apache HTTP Server to serve
different domains without using multiple IP addresses.
Note
Name-based virtual hosts only work with non-secure HTTP connections. If using virtual
hosts with a secure server, use IP address-based virtual hosts instead.
340