Managing HP Serviceguard for Linux Ninth Edition, April 2009

• To ensure the fastest cluster re-formations,
use the minimum value applicable to your
cluster. But keep in mind that this setting
will lead to a cluster re-formation, and to the
node being removed from the cluster and
rebooted, if a system hang or network load
spike prevents the node from sending a
heartbeat signal within the
MEMBER_TIMEOUT value. More than one
node could be affected if, for example, a
network event such as a broadcast storm
caused kernel interrupts to be turned off on
some or all nodes while the packets are
being processed, preventing the nodes from
sending and processing heartbeat messages.
See “Cluster Re-formations Caused by
MEMBER_TIMEOUT Being Set too Low”
(page 282) for troubleshooting information.
• For fewer re-formations, use a setting in the
range of 10 to 25 seconds (10,000,000 to
25,000,000 microseconds), keeping in mind
that a value larger than the default will lead
to slower re-formations than the default. A
value in this range is appropriate for most
installations
See also “What Happens when a Node Times
Out” (page 88), “Cluster Daemon: cmcld”
(page 39), and the white paper Optimizing
Failover Time in a Serviceguard Environment (version
A.11.19 and later) on docs.hp.com under High
Availability —> Serviceguard —>
White Papers.
Can be changed while the cluster is running.
AUTO_START_TIMEOUT The amount of time a node waits before it stops
trying to join a cluster during automatic cluster
startup. All nodes wait this amount of time for
other nodes to begin startup before the cluster
completes the operation. The time should be
selected based on the slowest boot time in the
cluster. Enter a value equal to the boot time of
the slowest booting node minus the boot time of
Cluster Configuration Planning 113