Installation guide

7.5.2.2 Follow Service Dependency
The follow service dependency makes use of rgmanager's RIND event scripting mechanism.
In order to activate the follow service dependency, central_processing must be enabled. Also,
the following events must be defined within the <rm> tag:
<rm>
<events>
<event class="service" name="service-ers">
notice("Event service triggered!");
evalfile("/usr/share/cluster/follow-service.sl");
follow_service("service:svc1", "service:svc2", "service:mastersvc");
</event>
<event class="node" name="node-ers">
notice("Event node triggered!");
evalfile("/usr/share/cluster/follow-service.sl");
follow_service("service:svc1", "service:svc2", "service:mastersvc");
</event>
</events>
</rm>
The event configuration for follow_service requires the following service names to be defined:
Service Description
svc1 The name of the service that should follow svc2 during a
failover operation.
svc2 The name of the service that should be followed by svc1
during a failover operation.
mastersvc The name of the service that should be started if only one
node is available.
During a failover operation, the follow service mechanism is working with the following rules:
Case 1: svc1 has to be relocated:
svc1 is relocated to a server where svc2 is not running.
If only one server is available and svc2 is running on it, svc1 will be relocated to the node only
if mastersvc==svc1,
Case 2: svc2 has to be relocated:
svc2 is relocated to the server where svc1 is running.
svc1 is relocated to another server.
If only one server is available, the service mastersvc==svc1|svc2 will be started on this node.
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