MONITORD(8) BSD System Manager's Manual MONITORD(8)NAMEmonitord — monitor system services for accidental termination
SYNOPSISmonitord [-f file -t interval]
DESCRIPTIONmonitord is a simple to use system service that allows one to easily mon‐
itor other system services for accidental termination. If they terminate
because of some internal bug or illegitimate action, such as a DoS
attack, they are restarted with the given username and parameters speci‐
fied in monitord.conf.
The two command line options are as follows:
-f file A custom configuration file may be used instead of the
default one: /usr/local/etc/monitord.conf.
-t interval
The time interval in seconds at which to check the system
processes, which are configured in monitord.conf. The default
interval is 10 seconds.
The configuration file for monitord, /usr/local/etc/monitord.conf, has a
simple format. It is divided into two parts. The first part contains gen‐
eral configuration informaion, which for now consists simply of the
admin's email and your email server. The second part consists of multiple
configuration lines for each service to be monitored. In this second
part, the first column contains the user under which the given service on
that line will be run if it needs to be restarted. The group to which the
user belongs will be grabbed from the password database.
The second column consists of the options to be used in monitoring that
particular service. Currently, three options are supported:
auto Indicates that the service should be automatically restarted
if it's found down. This is also the default behaviour when
neither auto nor noauto are specified.
noauto Indicates that the service should not be automatically
restarted if it's down.
alert Indicates that if this service is found down, the administra‐
tor is automatically notified via email, as specified in the
first part of the configuration file. Also, once a service is
restarted, this option will prompt monitord to notify the
administrator that it was successfully restarted.
The third column is the delay that will follow the startup of that par‐
ticular service. Some services take a while to start up, especially if
they need to perform preperatory tasks in a wrapper script, so to keep
monitord from attempting to restart a service after it's already begun
its startup proceedure but before it appears in the process table the
specified delay keeps monitord from checking that service for the speci‐
fied time in seconds.
The fourth and fifth columns are the service being monitored and script
used to start the service, respectively. Only the script column includes
the full path. If no special wrapper script is being used but instead the
service's binary is invoked directly simply include the path to the ser‐
vice in the script column. The service field should always contain the
name of the binary being executed. See examples in monitord.conf.
The last column, which is optional, may contain any parameters that
should be passed to the script (or binary as the case may be). For
instance, the following line would configure monitord to watch for
sendmail(8) and restart it, in case of termination, with the user root
and group wheel (which it would grab from the password database), and
then notify the administrator. monitord will wait 30 seconds after
attempting to restart sendmail before it checks to see if sendmail is up
and running:
root auto,alert 30 sendmail /usr/sbin/sendmail -bd -q60m
EXAMPLES
Here are a few more example service entries:
root auto,alert 30 syslogd /usr/sbin/inetd -wW
root auto,alert 30 syslogd /usr/sbin/syslogd
www auto,alert 60 httpd /usr/local/etc/rc.d/apache.sh
IMPLEMENTATION NOTES
This is version 0.4.1.
When using a time interval that is smaller than 5 seconds, an increas‐
ingly larger amount of CPU time will be used by the process. It is recom‐
mended that one keep the interval equal to or above 5 seconds. The
default of 10 seconds may be changed in config.h before compile time.
FILES
/usr/local/etc/monitord.conf configuration file
DIAGNOSTICS
When restarting a service which it is monitoring, monitord will notify
syslogd(8) of the event.
monitord should be run as root so that it can restart the services it is
monitoring with the correct username and group.
AUTHOR
This manual page was written by W. M. Shandruk ⟨walt@erudition.net⟩.
BUGS
There are no known bugs.
FreeBSD 4.3 August 21, 2003 FreeBSD 4.3
