Logging Control In CERN httpd

cern_httpd logs all the incoming requests to an access log file. It also has an error log where internal server errors are logged.

AccessLog - Set access log file name
ErrorLog - Set error log file name
LogFormat - Set access log file format
LogTime - Set time zone for log files
NoLog - No log entries for listed hosts/domains
CacheAccessLog - Log cache accesses to a different log file

Access Log File

Access log file contains a log of all the requests. The name of the log file is spesified either by -l logfile command line option, or with AccessLog directive:

        AccessLog /absolute/path/logfile

Error Log File

Error log contains a log of errors that might prove useful when figuring out if something doesn't work. Error log file name is set by ErrorLog directive:

        ErrorLog /absolute/path/errorlog

If error log file is not specified, it defaults to access log file name with .error extension. If the filename extension already exists, .error will replace it.

Previously every server used to have its own logfile format which made it difficult to write general statistics collectors. Therefore there is now a common logfile format (which will eventually become the default). Currently it is enabled by

        LogFormat  Common

The old CERN httpd format can be used by

        LogFormat  Old

Log Time Format

Times in the log file are by default local time. That can be changed to be GMT time by LogTime directive:

        LogTime  GMT

Default is:

        LogTime  LocalTime

Suppressing Log Entries For Certain Hosts/Domains

It's not always necessary to collect log information of accesses made by local hosts. The NoLog directive can be used to prevent log entry being made for hosts matching a given IP number or host name template:

        NoLog  template

Examples

        NoLog 128.141.*.*
        NoLog *.cern.ch
        NoLog *.ch  *.fr  *.it