Adding join conditions in event strategies
You configure how data from multiple paths in an event strategy rule is combined by developing a join logic. The join logic is configured in the Join shape on the basis of a when condition, where one property from the primary path equals another property from the secondary path. Every join logic can have multiple join conditions.
In an event strategy rule, access the Properties panel of a Join shape by double-clicking the shape.
Specify the join condition by performing the following actions:
When you join events, the property values from events that are on the primary path always take precedence over the property values from events that are on the secondary path. To preserve property values from the secondary path, you can create additional properties for storing those values.
Expand the drop-down list that is to the left of the equal sign and select an event property from the primary path.
Expand the drop-down list that is to the right of the equal sign and select an event property from the secondary path.
Create additional properties to store property values from the secondary path by performing the following actions:
In the Output section, expand the drop-down list and select the property from the secondary path whose values you want to store in another property.
Enter the name of the new property.
- Event Strategy rule form - Completing the Event Strategy tab
You use the Event Strategy tab to design and configure your event strategy components. A new instance of the Event strategy rule contains two shapes: Real-time data and Emit. You can add shapes by clicking the add icon that is available when you focus on a shape. To edit a shape, open the properties dialog box of a shape (by double-clicking the shape or by right-clicking and selecting the Properties option). The properties dialog box contains elements that are specific to a given shape.
- About Event strategy rule
Event strategies provide the mechanism to simplify the complex event processing operations. You specify patterns of events, query for them across a data stream, and react to the emerging patterns. The sequencing in event strategies is established through a set of instructions and execution points from real-time data to the final emit instruction. Between real-time data and emit, you can apply filter, window, aggregate, and static data instructions.
- Event Strategy rule - Completing the Create, Save As, or Specialization form