HP Serviceguard Identifying Heartbeat Subnets, Specifying Maximum Number of Configured Packages

315.244.65.0

415.244.56.0

In the Route connectivity section, the numbers on the left (1-4) identify which subnets are routed to each other (for example 15.13.164.0 and 15.13.172.0).

IMPORTANT: Note that in this example subnet 15.244.65.0, used by NodeA and NodeB, is not routed to 15.244.56.0, used by NodeC and NodeD.

But subnets 15.13.164.0 and 15.13.165.0, used by NodeA and NodeB, are routed respectively to subnets 15.13.172.0 and15.13.182.0, used by NodeC and NodeD. At least one such routing among all the nodes must exist for cmquerycl to succeed.

For information about configuring the heartbeat in a cross-subnet configuration, see the HEARTBEAT_IP parameter discussion under “Cluster Configuration Parameters ” (page 109).

Identifying Heartbeat Subnets

The cluster configuration file includes entries for IP addresses on the heartbeat subnet. HP recommends that you use a dedicated heartbeat subnet, and configure heartbeat on other subnets as well, including the data subnet. The heartbeat can be configured on an IPv4 or IPv6 subnet; see “About Hostname Address Families: IPv4-Only,IPv6-Only, and Mixed Mode” (page 106).

The heartbeat can comprise multiple subnets joined by a router. In this case at least two heartbeat paths must be configured for each cluster node. See also the discussion of HEARTBEAT_IP under “Cluster Configuration Parameters ” (page 109), and “Cross-Subnet Configurations” (page 30).

Specifying Maximum Number of Configured Packages

This specifies the most packages that can be configured in the cluster.

The parameter value must be equal to or greater than the number of packages currently configured in the cluster. The count includes all types of packages: failover, multi-node, and system multi-node.

The default is 300, which is the maximum allowable number of packages in a cluster.

NOTE: Remember to tune HP-UX kernel parameters on each node to ensure that they are set high enough for the largest number of packages that will ever run concurrently on that node.

Modifying the MEMBER_TIMEOUT Parameter

The cmquerycl command supplies a default value of 14 seconds for the MEMBER_TIMEOUT parameter. Changing this value will directly affect the cluster’s re-formation and failover times. You may need to increase the value if you are experiencing cluster node failures as a result of heavy system load or heavy network traffic; or you may need to decrease it if cluster re-formations are taking a long time.

You can change MEMBER_TIMEOUT while the cluster is running.

For more information, see the MEMBER_TIMEOUT parameter discussion under “Cluster Configuration Parameters ” (page 109), “What Happens when a Node Times Out” (page 88), and “Cluster Re-formations Caused by MEMBER_TIMEOUT Being Set too Low” (page 333).

Controlling Access to the Cluster

Serviceguard access-control policies define cluster users’ administrative or monitoring capabilities.

192 Building an HA Cluster Configuration