Using Serviceguard Extension for RAC, 7th Edition, September 2008
• 195 seconds
or
• 40 times Serviceguard NODE_TIMEOUT plus 25 times Serviceguard HEARTBEAT_INTERVAL
+ 120 seconds
When Cluster Interconnect Subnet Monitoring is not used
The Cluster Interconnect Monitoring is not used to monitor the CSS HB subnet and if the default
values of any of the following parameters has to be changed:
• Oracle Clusterware parameter CSS misscount
or
• Serviceguard cluster configuration parameter NODE_TIMEOUT
Then the CSS misscount parameter should be the greater of either:
• 195 seconds
or
• 25 times Serviceguard NODE_TIMEOUT + 15 seconds
Limitations of Cluster Communication Network Monitor
The Cluster Interconnect Monitoring feature does not coordinate with any feature handling
subnet failures (including self). The failure handling of multiple subnet failures may result in a
loss of services, for example:
• A double switch failure resulting in the simultaneous failure of CSS-HB subnet and SG-HB
subnet on all nodes of a two-node cluster. (Assuming the CSS-HB subnet is different from
SG-HB subnet). Serviceguard may choose to retain one node while the failure handling of
interconnect subnets might choose to retain the other node to handle CSS-HB network failure.
As a result, both nodes will go down.
NOTE: To reduce the risk of failure of multiple subnets simultaneously, each subnet must
have its own networking infrastructure (including networking switches).
• A double switch failure resulting in the simultaneous failure of CSS-HB subnet and RAC-IC
network on all nodes may result in loss of services (Assuming the CSS-HB subnet is different
from RAC-IC network). The failure handling of interconnect subnets might choose to retain
one node for CSS-HB subnet failures and to retain RAC instance on some other node for
RAC-IC subnet failures. Eventually, the database instance will not run on any node as the
database instance is dependent on clusterware to run on that node.
Cluster Interconnect Monitoring Restrictions
In addition to the above limitations the Cluster Interconnect Monitoring feature has the following
restrictions:
42 Serviceguard Configuration for Oracle 10g RAC