Managing relationships
Relationships allow you to specify how elements within the infrastructure are related. Relationships define dependencies between various monitored elements in a system and are used for Probable Cause Analysis, impact prediction, and event suppression.
For example, you can monitor an application and the host system. When a relationship is defined between an application and the host system, available events related to system A are suppressed by available events of system B. Now, if the system goes offline, both the system and the application become unavailable. However, due to the defined relationship, Infrastructure Management does not send out an alert for application availability. Only the system availability alert is sent out.
Relationships go a along way in customizing Infrastructure Management behavior. By managing relationships, higher level of validity can be achieved for both Probable Cause Analysis and events.
Probable Cause Analysis Relationships are static relationships (in the probable cause smart filter) based on static rules. Probable cause and Business Impact features use this information to filter out events and violations, not related to the queried event.
Instead of leveraging out-of-the-box knowledge about how various monitor instances relate to one another, the Probable Cause algorithm can leverage very specific user domain knowledge, an important factor in maximizing the power behind the Probable Cause feature.
Static Relationships relate different monitor types (not specific to any instances), and guide Probable Cause and Business Impact algorithms.
Relationships for probable cause are called Common relationships. Although common relationships can be created, BMC recommends using separate relationships for probable cause analysis.
User-defined relationships work together with static relationships to filter events. Generally, algorithms first check to see whether the event instance belongs to any instance relationships. If it does, then the algorithm applies those relationship filters. If the event instance does not belong to any instance relationship, it uses the static relationship rules.
BMC recommends use of group-level relationships. Such relationships are easy to manage, and all the instances added to the group inherit the relationship. This preserves all built-in rules even in environments where the instances are constantly being changed.