Using Serviceguard Extension for RAC, 7th Edition, September 2008

Figure 2-2 SG-HB/RAC-IC Traffic Separation
Each primary and standby pair protects against a single failure. With the SG-HB on more than
one subnet, a single subnet failure will not trigger a Serviceguard reconfiguration. If the subnet
with CSS-HB fails, unless subnet monitoring is used, CSS will resolve the interconnect subnet
failure with a CSS cluster reconfiguration. It will wait for the CSS misscount time interval before
handling the CSS-HB subnet failure (by bringing down the node on which the CSS-HB subnet
has failed).
The default value of CSS misscount in SGeRAC configurations is 600 seconds.
As shown in Figure 2-2, CLUSTER_INTERCONNECT_SUBNET can be used in conjunction with
the NODE_FAIL_FAST_ENABLED package configuration parameter to monitor the CSS-HB
network. A failure of CSS-HB subnet on a node should be handled by bringing down that node.
Therefore, set NODE_FAIL_FAST_ENABLED to YES for the package monitoring the CSS-HB
subnet. When Oracle Clusterware is configured as a multi-node package and
CLUSTER_INTERCONNECT_SUBNET is used to monitor the CSS-HB subnet, if the monitored
subnet fails, the failure of the CSS-HB subnet on a node will bring down the instance of the
multi-node package and the node where the subnet has failed.
A failure of CSS-HB subnet on all nodes will result in the multi-node package failing on the nodes
one by one (resulting in that node going down), and one instance of the multi-node package and
node will remain providing services to the clients.
Use a separate package to monitor only the CSS-HB subnet and have Oracle Clusterware
multi-node package depend on the package monitoring the CSS-HB subnet. The
NODE_FAIL_FAST_ENABLED parameter is set to NO for the Oracle Clusterware package, and is
set to YES for the package monitoring CSS-HB subnet (Oracle Cluster Interconnect Subnet Package
as shown in the package configuration parameters examples below).
NOTE: Do not configure CLUSTER_INTERCONNECT_SUBNET in the RAC Instance package
due to the RAC-IC network being the same as CSS-HB network.
The following is an example of the relevant package configuration parameters:
Oracle Clusterware Package:
PACKAGE_NAME CRS_PACKAGE
PACKAGE_TYPE MULTI_NODE
LOCAL_LAN_FAILOVER_ALLOWED YES
NODE_FAIL_FAST_ENABLED NO
38 Serviceguard Configuration for Oracle 10g RAC