Event Service Adapter Engineering Reports | OGC

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8.6 Event Service Adapter

This section describes discussions and decisions regarding the behavior of the Event Service Adapters.

8.6.1 Changes in schedule feed

In the schedule feed seen in Figure 5-2. SAA Pilot Study OGC Components, some entries are marked as pending. Thus, these schedule updates are not approved yet and might not become active. The question was whether these entries shall be translated into AIXM and sent to the Event Service or not. The decision was made to include these entries for the following reasons: Some applications might need these notifications. New pending activations could be sent to a decision maker who could then approve or disapprove them in a timely manner. The information on a possible activation of an airspace is also of interest as the airspace can be avoided in an earlier stage of the planning process. Clients not interested in pending activations can add a filter criterion to their subscription to excluded these events as this information is available in the reservation phase element.

8.6.2 Error handling

When an Event Service Adapter assembles an Event message for delivery to the Event Service, it is possible that the Event Service may not be able to process or retrieve sufficient information from the WFS to supply missing BASELINE details. In case of Event Service errors such as no SaaMessage, or no corresponding airspace gml:identifier is available from the WFS, it was decided that no event would be generated for the Pilot Study implementation. These types of errors were occurring due to data inconsistencies between the static airspace definitions and the airspace schedule reservations, and were not expected to occur in a production environment. Without eliminating these error states, the client software would require additional logic to deal with these exceptions, which should never appear in the operational system. It was agreed that the Pilot Study would not develop solutions for errors that are due to the prototypical state of the system, and that would not be present in the operational version.

8.7 Subscriber File Data Issues and Lessons Learned