Managing HP Serviceguard A.11.20.10 for Linux, December 2012

If NETWORK_POLLING_INTERVAL is defined to be
9,000,000 (9 seconds), then the polling happens at
9th second, 18th second and so on.
• Serviceguard also uses this parameter to calculate the
number of consecutive packets that each LAN interface
can miss/receive to mark a LAN interface DOWN/UP.
When an interface is monitored at IP-Level, and the
NETWORK_POLLING_INTERVAL is defined to be 8
seconds or more, then the number of consecutive
packets that each LAN interface can miss/receive to
be marked DOWN/UP is 2.
For example,
If NETWORK_POLLING_INTERVAL is defined to be 10,
then the detection of failure/recovery for a interface at
IP Level will happen at ~25 seconds.
The following are the failure/recovery detection times for
different values of Network Polling Interval (NPI) for an IP
monitored Ethernet interface:
Table 5 Failure Recovery Detection Times for an IP Monitored
Ethernet Interface
Failure/Recovery Detection Times (in seconds)
Values of
Network Polling
Interval (NPI) (in
seconds)
~ NPI x 8 - NPI x 91
~ NPI x 4 - NPI x 52
~ NPI x 3 - NPI x 43
~ NPI x 2 - NPI x 3>=4
IMPORTANT: HP strongly recommends using the default.
Changing this value can affect how quickly the link-level
and IP-level monitors detect a network failure. See
“Monitoring LAN Interfaces and Detecting Failure: Link Level”
(page 63).
Can be changed while the cluster is running.
CONFIGURED_IO_TIMEOUT_EXTENSION The number of microseconds by which to increase the time
Serviceguard waits after detecting a node failure, so as to
ensure that all pending I/O on the failed node has ceased.
This parameter must be set in the following cases.
• For extended-distance clusters using software mirroring
across data centers over links between iFCP switches;
it must be set to the switches' maximum R_A_TOV value.
96 Planning and Documenting an HA Cluster