Using Serviceguard Extension for RAC, 10th Edition, April 2011

The following describes the behavior of cluster interconnect subnet monitoring feature under the
following scenarios:
• For a multi-node package with CLUSTER_INTERCONNECT_SUBNET configured, upon an
explicit request to start the package on a node, no attempt to start the package instance on
that node will be made if the subnet is not up on that node.
• If a multi-node package with CLUSTER_INTERCONNECT_SUBNET configured is running on
only one node of the cluster, with the subnet that it monitors is down on all nodes of the cluster,
the restoration of the subnet on any other node does not affect the running instance. No attempt
will be made automatically to start the package instance on the restored node. An attempt to
start the instance of the package on the restored node will be made, if the user explicitly tries
to start the package instance.
• If a multi-node package with CLUSTER_INTERCONNECT_SUBNET is running on more than
one node of the cluster, upon a failure of the subnet on all nodes where the package is running,
all but one package instance will be halted one by one. Additionally, if
NODE_FAIL_FAST_ENABLED is set to “YES” for such a package, all but one node will be
brought down one by one. For example, one node will be brought down, cluster reformation
will happen, another node will be brought down, and cluster reformation will happen until
one node remains in the cluster.
NOTE: The CLUSTER_INTERCONNECT_SUBNET parameter is available only for use with
multi-node packages.
For more information on the Cluster Interconnect Subnet Monitoring feature, refer to chapter 2,
section “Cluster Communication Network Monitoring” (page 36). This section describes various
network configurations for cluster communications in an SGeRAC/10g or 11gR1/11gR2 RAC
cluster, and how the package configuration parameter CLUSTER_INTERCONNECT_SUBNET can
be used to recover from Oracle Cluster Communications network failures.
Configuring Packages for Oracle RAC Instances
Oracle instances can be configured as packages with a single node in their node list.
NOTE: Packages that start and halt Oracle instances (called instance packages) do not fail over
from one node to another, they are single-node packages. You should include only one NODE_NAME
in the package ASCII configuration file. The AUTO_RUN setting in the package configuration file
will determine whether the RAC instance will start up as the node joins the cluster. Your cluster
may include RAC and non-RAC packages in the same cluster.
Configuring Packages for Oracle Listeners
Oracle listeners can be configured as packages within the cluster (called listener packages). Each
node with a RAC instance can be configured with a listener package. Listener packages are
configured to automatically fail over from the original node to an adoptive node. When the original
node is restored, the listener package automatically fails back to the original node.
In the listener package ASCII configuration file, the FAILBACK_POLICY is set to AUTOMATIC.
The SUBNET is a set of monitored subnets. The package can be set to automatically startup with
the AUTO_RUN setting.
Each RAC instance can be configured to be registered with listeners that are assigned to handle
client connections. The listener package script is configured to add the package IP address and
start the listener on the node.
For example, on a two-node cluster with one database, each node can have one RAC instance
and one listener package. Oracle clients can be configured to connect to either package IP address
(or corresponding hostname) using Oracle Net Services. When a node failure occurs, existing
client connection to the package IP address will be reset after the listener package fails over and
Configuring Packages for Oracle RAC Instances 19