mathopd(8) Advanced Hypertext Tranfer Protocol Server

SYNOPSIS

mathopd [ -ndtv ] [ -f config_file ]

OPTIONS

-n
If this option is supplied, Mathopd continues to run in the foreground after initialization. This is useful for debugging purposes.

-d
If this option is supplied, Mathopd starts up in debugging mode. Debugging can be turned on and off while the server is running; see the section on signals below.

-t
If this option is supplied, Mathopd will write diagnostics to the standard error channel as well as the error log. The option is named after the tee(1) program.

-v
If this option is supplied, Mathopd prints its version number and exits.

-f config_file

Use the configuration file specified by config_file. If the -f option is not used, Mathopd expects a configuration file from standard input. This is mainly for historic reasons; there is no reason why one should not use the -f flag. mathopd.conf(5) describes the syntax of the mathopd configuration file.

SIGNALS

While the server is running, is reacts to certain signals. If a PIDFile is specified in the configuration file, you can send signals to Mathopd using something like


   # kill -<signal> `cat /var/run/mathopd.pid`

from the command line, assuming the PIDFile is /var/run/mathopd.pid.

A list of signals and their effects follows.

SIGHUP
If this signal is received, Mathopd will reopen its access and error log files. See the section on log files below.

SIGTERM SIGINT
These signals have identical effects: they stop Mathopd immediately, that is, all connections are closed and all server sockets as well. Note that the fact that SIGINT stops the server means that you can stop Mathopd by pressing Ctrl-C (or whatever key has the interrupt function) if it was started with the -n flag.

SIGQUIT
This signal toggles the debugging flag: if debugging was turned off before this signal was sent, it will be turned on, and vice versa.

SIGUSR1
This signal disconnects all clients, if any from the server. New connections can still be made after this.

SIGUSR2
This signal closes the server socket(s). No more connections will be received after this. Requests that are active at the time of the signal will be completed. After all active requests are timed out or done, Mathopd will exit. Use this signal for a 'graceful exit'.

EXIT

Mathopd will exit voluntarily (as opposed to crash :) for a few reasons:

   -
after reception of a SIGTERM or SIGINT signal

   -
when no active connections and no active servers remain; this will be the case some time after delivery of SIGUSR2, or (rather perversely) if Mathopd was started up with a configuration file that did not contain any Server keywords

   -
if it cannot open the Log, ErrorLog, or PIDFile; this can only be the case when the server is started up; if Mathopd fails to open a logfile while it is running, it will continue to use the logfile that it already opened (see below)

   -
when it can not write to the access or error log; for example, if the disk partition that contains the access or error log gets filled up, Mathopd will die when it tries to write there.

LOG FILES

Each hour Mathopd will re-open its access and error log, as if it had received a SIGHUP signal. For example, if you have the following in your configuration file


   Log /var/mathopd/accesslog
   ErrorLog /var/mathopd/errorlog

and rename /var/mathopd/accesslog to /var/mathopd/accesslog.old, Mathopd will continue to log in accesslog.old, but will switch to accesslog at the start of the next hour (with one exception: if Mathopd cannot open a new accesslog for any reason, it will *still* continue to log to accesslog.old.) Something similar applies to the ErrorLog.

There are two exceptions to the above: if the value of Log or ErrorLog is either "/dev/stdout" or "/dev/stderr", then the log will not be rotated: mathopd will not try to re-open these files. This is because /dev/stdout and /dev/stderr will be gone once the server has started up.

The name of the Log, ErrorLog and ChildLog will be 'strftime- expanded'. This means that any occurrence of, say, '%Y' in the name will be expanded to the current (4-digit) year.

For example: suppose the configuration file reads as follows


   Log /var/mathopd/log.%Y%m%d

In that case, Mathopd will open /var/mathopd/log.20031204 when it is started up on 4 Dec 2003, and will automatically close that file and open /var/mathopd/log.20031205 at the start of the next day.

For more information on the % constructions, see the manual pages for date(1) and strftime(3).

AUTHOR

Mathopd was written and is copyright by Michiel Boland.

Man page contributed by Juergen Daubert.