Starting Tracker

Reads head detections from a JSON topic, and creates tracks of the detected persons.

Prerequisites

It is assumed that Multi-Graph Runner (MGR) is running, because object detection records are necessary input. For more information on running MGR, see Starting Multi-Graph Runner.

Required input topic:

base.cam.0.dets.ObjectDetectionRecord.json

Note: Not available for multiple input streams. This microservice can only process one input.

For information on Tracker configuration, see Configuring Tracker.

Starting the Tracker service

To start Tracker:

1. Run the microservice:

   Attention! Before starting this microservice, the command below silently stops and removes the Docker container named uvap_kafka_tracker, if such already exists.

   $ "${UVAP_HOME}"/scripts/run_kafka_tracker.sh -- --net=uvap
   

   The output of the above command contains the following:

   • Information about pulling the required Docker image
   • The ID of the Docker container created
   • The name of the Docker container created: uvap_kafka_tracker

   There are more optional parameters for the run_kafka_tracker.sh script to override defaults. Use the --help parameter to get more details.

2. Wait for approximately 30 seconds, then check if the containers are still running:

   $ docker container inspect --format '{{.State.Status}}' uvap_kafka_tracker
   

   Expected output:

   running
   

3. Check the output:

   $ docker exec kafka kafka-console-consumer --bootstrap-server kafka:9092 \
     --topic base.cam.0.tracks.TrackChangeRecord.json
   

   Expected example output:

   {"end_of_track":false,"detection_key":"1563262804472_0","point":{"x":598,"y":150}}
   {"end_of_track":false,"detection_key":"1563262804472_2","point":{"x":804,"y":249}}
   {"end_of_track":true,"detection_key":""}
   % Reached end of topic base.tracks.TrackChangeRecord.json [0] at offset 4916
   {"end_of_track":false,"detection_key":"1563262804847_0","point":{"x":598,"y":150}}
   {"end_of_track":false,"detection_key":"1563262804847_2","point":{"x":804,"y":249}}
   {"end_of_track":false,"detection_key":"1563262804847_1","point":{"x":1077,"y":353}}
   

The following output topic is created:

base.cam.0.tracks.TrackChangeRecord.json