Managing HP Serviceguard A.11.20.10 for Linux, December 2012

7.7.5 Configuring Cross-Subnet Failover
To configure a legacy package to fail over across subnets (see “Cross-Subnet Configurations”
(page 27)), you need to do some additional configuration.
Suppose that you want to configure a package, pkg1, so that it can fail over among all the nodes
in a cluster comprising NodeA, NodeB, NodeC, and NodeD.
NodeA and NodeB use subnet 15.244.65.0, which is not used by NodeC and NodeD; and
NodeC and NodeD use subnet 15.244.56.0, which is not used by NodeA and NodeB. (See
“Obtaining Cross-Subnet Information” (page 150) for sample cmquerycl output).
7.7.5.1 Configuring node_name
First you need to make sure that pkg1 will fail over to a node on another subnet only if it has to.
For example, if it is running on NodeA and needs to fail over, you want it to try NodeB, on the
same subnet, before incurring the cross-subnet overhead of failing over to NodeC or NodeD.
NOTE: If you are using a Metrocluster, you can configure site aware cluster using the SITE and
SITE_NAME parameters. For more information about SITE and SITE_NAME parameters, see
“Cluster Configuration Parameters ” (page 86).
Assuming nodeA is pkg1’s primary node (where it normally starts), create node_name entries in
the package configuration file as follows:
node_name nodeA
node_name nodeB
node_name nodeC
node_name nodeD
7.7.5.2 Configuring monitored_subnet_access
In order to monitor subnet 15.244.65.0 or 15.244.56.0, you would configure
monitored_subnet and monitored_subnet_access in pkg1’s package configuration file
as follows:
monitored_subnet 15.244.65.0
monitored_subnet_access PARTIAL
monitored_subnet 15.244.56.0
monitored_subnet_access PARTIAL
NOTE: Configuring monitored_subnet_access as FULL (or not configuring
monitored_subnet_access) for either of these subnets will cause the package configuration
to fail, because neither subnet is available on all the nodes.
7.7.5.3 Creating Subnet-Specific Package Control Scripts
Now you need to create control scripts to run the package on the four nodes.
IMPORTANT: In a cross-subnet configuration, you cannot share a single package control script
among nodes on different subnets if you are using relocatable IP addresses. In this case you will
need to create a separate control script to be used by the nodes on each subnet.
In our example, you would create two copies of pkg1’s package control script, add entries to
customize it for subnet 15.244.65.0 or 15.244.56.0, and copy one of the resulting scripts to
each node, as follows.
7.7 Configuring a Legacy Package 231