Using Serviceguard Extension for RAC, 6th Edition, April 2008

NOTE: HP and Oracle support SGeRAC to provide group membership to CSS.
Serviceguard Cluster Timeout
The Serviceguard cluster heartbeat timeout is set according to user requirements for
availability. The Serviceguard cluster reconfiguration time is determined by the cluster
timeout, configuration, the reconfiguration algorithm, and activities during
reconfiguration.
CSS Timeout
When SGeRAC is on the same cluster as Oracle Cluster Software, the CSS timeout is
set to a default value of 600 seconds (10 minutes) at Oracle software installation.
This timeout is configurable with Oracle tools and should not be changed without
ensuring that the CSS timeout allows enough time for Serviceguard Extension for RAC
(SGeRAC) reconfiguration and to allow multipath (if configured) reconfiguration to
complete.
On a single point of failure, for example, node failure, Serviceguard reconfigures first
and SGeRAC delivers the new group membership to CSS via NMAPI2. If there is a
change in group membership, SGeRAC updates the members of the new membership.
After receiving the new group membership, CSS in turn initiates its own recovery
action as needed and propagates the new group membership to the RAC instances.
NOTE: As a general guideline, the CSS TIMEOUT should be greater of either 180
seconds or 25 times the Serviceguard NODE_TIMEOUT.
RAC IMR Timeout
RAC instance IMR timeout is configurable. RAC IMR expects group membership
changes to occur within this time or IMR will begin evicting group members. The IMR
timeout must be above the SGeRAC reconfiguration time and adhere to any
Oracle-specified relation to CSS reconfiguration time.
Oracle Cluster Software
Oracle Cluster Software should be started after activating its required shared storage
resources. Shared storage resources can be activated after SGeRAC completes startup.
Oracle Cluster Software should not activate any shared storage. Similarly, for halting
SGeRAC at run level 3 and removing shared storage resources from Oracle Cluster
Software, Oracle Cluster Software must be halted first.
36 Serviceguard Configuration for Oracle 10g RAC