BIG DATA DEMO

ATS TAXI DATA SIMULATOR

The ATS Taxi data simulator is used to provide a simulated real time feed of up to 537 taxi cabs using data provided for free by cabspotting.org

The simulator is provided as ats_taxi_simulator.py, which will open one or more waypoint files from the cabspottingdata subdirectires and transmit them in real time to the backend system.

STANDALONE TESTING

To test the taxi data simulator a dummy service is setup to receive data delivered by the taxi simulator. Both the simulator and dummy service use a local RVI node to communicate.

BUILDING THE RVI NODE

If no existing RVI node exist one can be built and started on yo Check out the following repo:

https://github.com/PDXostc/rvi

and follow the instructions at in BUILD.md.

Setup the RVI node

In the rvi directory, create a node using the standard backend setup:

./scripts/setup_rvi_node.sh  -d -n backend -c backend.config

Start the RVI node

In the rvi directory, launch the newly setup node in developer mode:

./scripts/rvi_node.sh -n backend

Exit out of the RVI node by pressing ctrl-c ctrl-c

REGISTERING THE DUMMY SERVICE

Go to the rvi/python subdirectory.

Ensure that jsonprclib is installed as shown in rvi/python/README.md

Go to the rvi/python directory and launch the dummy service, having it connect to the local RVI node:

./rvi_service.py  http://localhost:8801 /logging/report

[1/2] STARTING THE SIMULATOR

The simulator is started with one or more waypoint files from the unpacked cabspottingdata.tar.gz tarball.

Start the simulator from the directory where this README.md file resides:

./ats_taxi_simulator.py http://localhost:8801 cabspottingdata/new_eshroa.txt

The simulator will connect to the local RVI node and send content of a single wayppoint file cabspottingdata/new_eshroa.txt to the dummy service registered above.

[2/2] USING DOCKER TO HOST THE SIMULATOR

All necessary files are present to create and execute a docker container hosting the simulator.

NOTE: Since docker containers have issues connecting to localhost, the instructions below use the public RVI at rvi1.nginfotpdx.net.
In these cases, the dummy service should be executed directly on the rvi1 host to avoid firewall issues when the RVI node sends HTTP requests to it

Build the simulator docker container

Create a docker container for the simulator by running the following command in the directory where this README.md file resides:

sudo docker build  -t ats_simulator .

Launch the simulator docker container

Launch the docker container, having it connect to the RVI node at rvi1.nginfotpdx.net:

sudo docker run -ti --rm ats_simulator \
   http://rvi1.nginfotpdx.net:8801 cabspottingdata/new_eshroa.txt

RVI SERVICVES AND THEIR FORMATS

The following chapters describe the service invocation between the taxi simulator and backend node.

SUBSCRIBE (NOT IMPLEMENTED)

Subscribe commands are sent from the backend server to a vehicle in order to setup a regular reporting of specific data from vehicle to server.

Reporting will be done through the report command.

Multiple subscribe commands can be sent, where all indicated channels are reported

 {
	 "jsonrpc": "2.0",
     "id": 1,
     "method": "message",
	 "params": {
		 "service": "jlr.com/vin/123456/logging/subscribe",
	     "channels":, ["location", "odometer", "speed"],
		 "reporting_interval": 5000
	 }
 } 

Parameters

• channels
  Specifies the channels that we want reported back to the server.

• reporting_interval
  Specifies the number of milliseconds between each data sample that is to be sent back end server. If the reporting interval is a negative integer, the channel's value will be reported at the given (absolute value) interval, or when the value changes, whatever happens first.

UNSUBSCRIBE

Unubscribe commands are sent from the backend server to a vehicle in order to stop reporting of one or more data channels previously setup through a subscribe command.

 {
	 "jsonrpc": "2.0",
     "id": 2,
     "method": "message",
	 "params": {
		 "service": "jlr.com/vin/123456/logging/unsubscribe",
	     "channels":, ["location", "odometer", "speed"]
	 }
 } 

Parameters

• channels
  Specifies the channels to stop reporting. If a channel has been specified several times by multiple subcribe commands, all subscriptions to the channel are removed.

REPORT

Publish commands are sent from the device to the backend server to report a batch of values for channels previously subscribed to by a subscribe command. Multiple values for a single channel can be provided in a single report.

Each channel is reported with its channel name, its value, and the UTC msec timestamp when the value was sample.

 {
	 "jsonrpc": "2.0",
     "id": 3,
     "method": "message",
	 "params": {
		 "service": "jlr.com/backend/logging/report",
         "vin":  "1234",
         "timestamp":  1415143459110,
	     "data":, [
			 { "channel": "odometer", "value": 10022 },
			 { "channel": "odometer", "value": 10023 },
			 { "channel": "speed", "value": 113 },
			 { "channel": "location",
			   "value": { "lat": 39.0319, "lon": 125.7538, "alt": 222.3 } } 		 
         ]
	 }
 } 

Parameters

• data
  Contains an array of all reported data points.

• channel
  Contains the name of the channel a data point is reporetd for. Matches the channel name in a previously issued subscribe command.

• value
  Specifies the value of the given channel at the given time. The actual value can be a string, a double, or a JSON object, and is implicitly defined by the channel name.

• timestamp
  Specifies the timestamp in millisecond UTC when the value was sampled from the vehicle.