Specifications
Tuning the LifeKeeper Heartbeat
Do Not Switch Over
Resources (default)
LifeKeeper will not bring resources in service on a backup server
during an orderly shutdown.
Switch Over Resources
LifeKeeper will bring resources in service on a backup server during
an orderly shutdown.
The Shutdown Strategy is set by default to "Do Not Switch Over Resources." You should decide
which strategy you want to use on each server in the cluster, and if you wish, change the Shutdown
Strategy to"Switch Over Resources".
For each server in the cluster:
1. On the Edit Menu, point to Server and then click Properties.
2. Select the server to be modified.
3. On the General Tabof the Server Properties dialog, select the Shutdown Strategy.
Note: The LifeKeeper process must be running during an orderly shutdown for the Shutdown
Strategy to have an effect. If LifeKeeper is not running or the resources are not currently in service,
the resources will not switch over.
Tuning the LifeKeeper Heartbeat
Overview of the Tunable Heartbeat
The LifeKeeper heartbeat is the signal sent between LifeKeeper servers over the communications
path(s) to ensure each server is "alive".There are two aspects of the heartbeat that determine how
quickly LifeKeeper detects a failure:
l Interval: the number of seconds between heartbeats.
l Number of Heartbeats: the number of heartbeats that can be missed before LifeKeeper
determines that the communications path is dead, triggering a failover.
The heartbeat values are specified by two tunables in the LifeKeeper defaults file
/etc/default/LifeKeeper. These tunables can be changed if you wish LifeKeeper to detect a server
failure sooner than it would using the default values:
l LCMHBEATTIME (interval)
l LCMNUMHBEATS (number of heartbeats)
The following table summarizes the defaults and minimum values for the tunables over both TCP and
TTY heartbeats. The interval for a TTY communications path cannot be set below 2 seconds because
of the slower nature of the medium.
Tunable Default Value Minimum Value
LCMHBEATTIME 5 1 (TCP) 2 (TTY)
LCMNUMHBEATS 3 2 (TCP or TTY)
72Configuration