Managing Serviceguard A.11.20, March 2013

Table 7 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
WARNING! If the values of
NETWORK_POLLING_INTERVAL is greater than or equal
to 8, a single lost link-level packet will cause a LAN to be
marked as DOWN.
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 70), “Monitoring LAN Interfaces and Detecting
Failure: IP Level” (page 74), and “Reporting Link-Level and
IP-Level Failures” (page 77).
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.
NOTE: CONFIGURED_IO_TIMEOUT_EXTENSION
is supported only with iFCP switches that allow you to
get their R_A_TOV value.
• For switches and routers connecting an NFS server and
cluster-node clients that can run packages using the
NFS-mounted file system; see “Planning for
NFS-mounted File Systems” (page 136).
To set the value for the
CONFIGURED_IO_TIMEOUT_EXTENSION, you must
first determine the Maximum Bridge Transit Delay
(MBTD) for each switch and router. The value should
be in the vendors' documentation. Set the
CONFIGURED_IO_TIMEOUT_EXTENSION to the sum
of the values for the switches and routers. If there is
more than one possible path between the NFS server
Cluster Configuration Planning 127