NAME¶
cmannotifyd - CMAN Notification Daemon
SYNOPSIS¶
cmannotifyd [-f] [-d]
DESCRIPTION¶
The
cmannotifyd daemon talks to CMAN and provides a mechanism to notify
external entities about cluster changes.
CMAN dispatches 3 kind of notifications:
- CMAN_REASON_TRY_SHUTDOWN when cman requests to all clients if it is allowed to
shutdown.
- CMAN_REASON_STATECHANGE when cman detects a node joining or leaving the
cluster.
- CMAN_REASON_CONFIG_UPDATE when a configuration change event has been
detected/requested.
These notifications are then dispatched to the shell script
cman_notify
in the environment variable CMAN_NOTIFICATION.
cman_notify will then execute all the scripts in the configured
notification directory (default: /etc/cluster/cman-notify.d) passing a very
minimal set of envvars including, of course, the CMAN_NOTIFICATION= type. The
execution order is set by the filename as shown by "LC_ALL=C ls
-las".
cmannotifyd logs are stored in the default log file
(/var/log/cluster/cmannotifyd.log).
cman_notify logs are stored in the default log file
(/var/log/cluster/cman_notify.log). By default the output from the scripts
executed by
cman_notify is redirected to /dev/null. Users can either
set CMAN_NOTIFICATION_DEBUG=1 in their environment or set proper debug
configuration in cluster.conf to redirect scripts output to the cman_notify
log file.
NOTES¶
cmannotifyd does not block on cman_notify nor check the exit status of the
script.
Notifications are dispatched in the same order as they arrive, one by one.
CMAN_REASON_TRY_SHUTDOWN is passed to scripts for information only, they can not
influence cman's decsion about whether or not to shut down.
CMAN_REASON_STATECHANGE also implies CMAN_NOTIFICATION_QUORUM exported in the
environment. CMAN_NOTIFICATION_QUORUM will be set to 1 (when the node is part
of a quorate cluster) or 0 (otherwise).
A template for cman_notify scripts can be found in the doc/ directory.
OPTIONS¶
- -f
- Run in the foreground (do not fork / daemonize).
- -d
- Enable debug output.