• Clemens Schotte
• Martin Weber
• Sander van den Hoven
• Christian Geuer-Pollmann

Traffic speed in the Netherlands is measured by two cameras with license plate detection, placed a few kilometers from each other. By measuring at which point in time a car enters an area and leaves it minutes later, the system is able to calculate average speed, and determine traffic rule violations.

• A VisualStudio-based load test agent simulates events of cars entering and leaving a measurement area.
• These events fly in as HTTP POSTs, are augmented with server-side time stamps, and stored in Azure EventHub (round-robin preferrably).
• A Service Fabric cluster runs consumers to get messages out of EventHub.
• For each entering event, a stateful actor is created.
• When the leaving event occurs, the stateful actor computes the average speed, and sends a message to a stateless DB-writer-actor.
• The DB-writer-actor batches DB writes for efficiency, to avoid all stateful actors making their own database connections.