Managing HP Serviceguard A.11.20.10 for Linux, December 2012

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 250) 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 72), “Cluster Daemon: cmcld” (page 32), and the
white paper Optimizing Failover Time in a Serviceguard
Environment (version A.11.19 and later) at http://
www.hp.com/go/linux-serviceguard-docs.
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 the fastest booting node plus 600
seconds (ten minutes).
Default is 600,000,000 microseconds.
Can be changed while the cluster is running.
NETWORK_POLLING_INTERVAL Specifies the Interval at which Serviceguard periodically
polls all the LAN Interfaces (link-level and the ones
configured for IP MONITOR)
Default is 2,000,000 microseconds (2 seconds). This means
that the network manager will poll each network interface
every 2 seconds, to make sure it can still send and receive
information.
The minimum value is 1,000,000 (1 second) and the
maximum value supported is 30 seconds.
For example,
• If NETWORK_POLLING_INTERVAL is defined to be
6,000,000 (6 seconds), then the polling happens at
6th second, 12th second and so on.
4.7 Cluster Configuration Planning 95