Section: Maintenance Commands (8)
Updated: Tue Sep 21 1999
Index Return to Main Contents


pulse - heartbeating daemon for monitoring the health of cluster nodes  


pulse [-c file|--configfile= file] [-n|--nodaemon]
[--forceactive] [--lvs= path] [--fos= path]
[-v|--verbose] [-t|--test-start] [--norun]
 [-?|--help] [--usage] [--version]


pulse is a daemon used by lvsd nodes to monitor one another's health and to initiate the failover of the lvsd or fos daemon. It makes use of the lvs.cf(5) configuration file for items such as length of time between heartbeats and length of time before declaring the remote server to be dead and initiate a failover.

pulse, which runs on the primary and backup nodes, is used by each to determine that the other is still alive. If the backup node fails to receive a heartbeat from the primary node after a set amount of time (specified in lvs.cf), it will assume ownership of all virtual service(s) being provided by the primary node. Its takeover process includes bringing up aliased device(s) for all virtual service(s) as well as sending out gratuitous ARPs to associate the floating IP(s) with the MAC address of the backup node.

If and when a failed primary node returns to a functioning status, it assumes the backup role unless specifically forced to assume the primary role. To reduce the number of faults seen by clients and avoid the breaking persistent client connections, you should minimize the number of failovers.  


-c file|--configfile= file
Normally, pulse uses lvs.cf as its configuration file, but this can be overridden and another file can be used.
Normally, pulse runs as a daemon but with this option runs in the foreground. When running in this mode, pulse sends all output to STDOUT instead of to syslog.
When this flag is used, the machine that pulse runs on will forceably take over as the primary lvsd router and other machine will become the backup.
--lvs= path
By default, pulse looks in /usr/sbin for lvsd; use path to tell pulse to look elsewhere for the program.
--fos= path
By default, pulse looks in /usr/sbin for fos; use path to tell pulse to look elsewhere for the program.
Runs pulse in a test mode. Reports, but does not actually start, the rest of the daemom processes (lvsd, fos, etc.).
Historical. Same as --test-start.
Displays debugging information
Shows a verbose usage listing.
Outputs a terse argument summary.
Displays program version.



lvs.cf(5), ipvsadmn(8), lvsd(8). fos(8). nanny(8).



Erik Troan <ewt@redhat.com>




linux.jgfs.net manual pages