Managing HP Serviceguard for Linux, Tenth Edition, September 2012

generic_resource_up_criteria, then the generic resource is marked as
'down' on that node.
NOTE: If a simple resource is down on a particular node, it is down on that node for
all the packages using it whereas, in case of an extended resource the resource may be
up on a node for a particular package and down for another package, since it is
dependent on the generic_resource_up_criteria.
Additionally, in a running package configured with a generic resource:
• Any failure of generic resource of evaluation type "before_package_start" configured
in a package will not disable the node switching for the package.
• Any failure of generic resource of evaluation type "during_package_start" configured
in a package will disable the node switching for the package.
“Choosing Switching and Failover Behavior” (page 124) provides advice on choosing
appropriate failover behavior.
Service Restarts
You can allow a service to restart locally following a failure. To do this, you indicate a
number of restarts for each service in the package control script. When a service starts,
the variable service_restart is set in the service’s environment. The service, as it
executes, can examine this variable to see whether it has been restarted after a failure,
and if so, it can take appropriate action such as cleanup.
Network Communication Failure
An important element in the cluster is the health of the network itself. As it continuously
monitors the cluster, each node listens for heartbeat messages from the other nodes
confirming that all nodes are able to communicate with each other. If a node does not
hear these messages within the configured amount of time, a node timeout occurs,
resulting in a cluster re-formation and later, if there are still no heartbeat messages
received, a reboot. See “What Happens when a Node Times Out” (page 87)
90 Understanding Serviceguard Software Components