Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Planning and Documenting an HA Cluster
Cluster Configuration Planning
Chapter 4110
STATIONARY_IP
The IP address of each monitored subnet, other than
those that carry the cluster heartbeat. You can identify
any number of subnets to be monitored. If you want to
separate application data from heartbeat messages,
define monitored non-heartbeat subnets here.
A stationary IP address can be either an IPv4 or an
IPv6 address. For more information about IPv6
addresses, see Appendix E, “IPv6 Network Support,” on
page 357.
For information about changing the configuration
online, see “Changing the Cluster Networking
Configuration while the Cluster Is Running” on
page 256.
HEARTBEAT_INTERVAL
The normal interval between the transmission of
heartbeat messages from one node to the other in the
cluster. Enter a number of microseconds. The default
value is 1,000,000 microseconds; setting the parameter
to a value less than the default is not recommended.
The default should be used where possible. The
maximum value recommended is 15 seconds, and the
maximum value supported is 30 seconds or half the
value of NODE_TIMEOUT (below).
Can be changed while the cluster is running.
NODE_TIMEOUT
The time, in microseconds, after which a node may
decide that another node has become unavailable and
initiate cluster reformation.
Maximum value: 60,000,000 microseconds (60
seconds).
Minimum value: 2 * HEARTBEAT_INTERVAL
Default value: 2,000,000 microseconds (2 seconds).
Recommendations: You need to decide whether it's
more important for your installation to have fewer
cluster reformations, or faster reformations: