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.