Managing HP Serviceguard for Linux, Sixth Edition, August 2006

Planning and Documenting an HA Cluster
Cluster Configuration Planning
Chapter 4 103
NOTE The use of a private heartbeat network is not advisable
if you plan to use Remote Procedure Call (RPC)
protocols and services. RPC assumes that each network
adapter device or I/O card is connected to a route-able
network. An isolated or private heartbeat LAN is not
route-able, and could cause an RPC request-reply,
directed to that LAN, to risk time-out without being
serviced.
NFS, NIS and NIS+, and CDE are examples of RPC
based applications that are frequently used on UNIX
systems. Other third party and home-grown
applications may also use RPC services directly
through the RPC API libraries. If necessary, consult
with the application vendor to confirm its usage of
RPC.
STATIONARY_IP
The IP address of each monitored subnet that does not
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 a monitored non-heartbeat subnet here.
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. This value
should be at least half the value of
NODE_TIMEOUT
(below).