User Guide › Service Level Management › Contracts › Event Reusability

Event Reusability

A typical CA Business Service Insight installation often includes many metrics that receive the same events and performs very similar calculations. Usually the difference between such metrics calculations is in the last stages of processing. In such cases there is a need to split calculations into two phases:

• Phase 1 - One metric performs the calculation and the results serve other metrics.
• Phase 2 - The collection of metrics performs calculations based on the already calculated results of the metric from phase 1.

To split the calculation between several metrics into phases, events from one metric can be sent to other metrics. These events are called intermediate events and are written to a separate table (T_INTERMEDIATE_DATA). When event-sending metrics are recalculated, event-receiving metrics are also recalculated. Metric events cannot be corrected.

The system warns for a metric name change in case there are other metrics in the system, which are registered to receive events from this metric.

There are two types of metrics that enable sending events between metrics:

Sender

A metric that creates internal events. The events are created in the Business Logic formula of the metric and are added to the T_INTERMEDIATE_DATA table.

Consumer

A metric that consumes internal events. To define such a metric, registration to the metric it wished to receive events from is required. According to this registration the metric reads the relevant events from the T_INTERMEDIATE_DATA table.

Note: It is possible for a metric to send and receive events from a different metric as long as no loop occurs.

Event Reusability is useful when:

• One metric calculation is based on the result of another metric's calculations. No need to calculate the same thing in several places.
• Splitting the calculation between several metrics.
• Basing the calculation of a single business logic on several results from different metrics in different contracts.

Note: In generated reports, it is possible to view the intermediate data that the calculations are based on in addition to the raw data.