MongoDB .local London 2019: The Tech Behind Connected Car

Connected Car
the tech behind
Dr. Patrick Bartsch
Head of Technology Specialists & Future Tech in Connected Car
September 2019

● 18+ years experience in #automotive
○ 5 yrs IAV
○ 10 yrs Volkswagen
○ 2 yrs Audi
○ > 1 yr Jaguar Land Rover
● Passionate swimmer and runner, coder and car
nut
● How to contact me
○ https://github.com/wzr1337
○ https://twitter/wzr1337
○ https://linkedin.com/in/patrickbartsch
Who am I?

● 2 UK heritage brands
○ Jaguar
○ Land Rover
● shipping ~600.000 cars a year
● serving customers world wide
● won 3 car of the year awards in 2019
○ best car Europe
○ best car World
○ best Green car
● building connected cars since 2014
Who is Jaguar Land Rover?

● 1.7M active cars
● launched in 2014
● Offering:
○ InControl
○ Live
● Team distributed over 5
different Geos
Jaguar Land Rovers connected car

● Infotainment HTML5 Apps
● Always fresh as downloaded on demand
● Uses real estate in
○ main screen
○ side panel
○ blade screen
● Offers
○ online streaming media
○ weather
○ news
○ flight tracker
○ air quality (China)
Live Apps

● Jaguar and Land Rover versions available
● remote control
● vehicle health information
● vehicle health alerts
● journey logs
● general vehicle information
● electric vehicle interactions
● …
InControl V2

● car is offline often
○ goes to sleep after sitting idle for a certain time
○ needs to be woken up
● the quality of connectivity is usually weak
● cars go at high speeds
● the available bandwidth is small compared to land
lines – today (5G promises to deliver better)
● different legislation in different markets, but car are
mobile
○ China
○ Russia
○ Turkey
Why is the car a different IoT device?

● C3 – Client-Cloud-Car setup
● APIs connect millions to millions
● Cloud is either on-prem, hybrid or public cloud
● Additional components connected
○ factories
○ OEM systems
● Supported client categories
○ customer applications and assistants
○ 3rd party service providers (e.g. RSA)
○ call centers (e.g. concierge services)
○ web portal for dealers and customers
○ home automation
○ etc.
Connectivity Cloud – A general Architecture

● VSS
○ implemented in production
○ used for in vehicle infotainment
○ to become a standard soon
● RSI
○ for web APIs mainly
○ not yet standardized
○ debate about integration with VSS onboing
Engagement in the W3C

● stands for RESTful Service Interface (aka viwi)
● It is REST+N,
allows subscriptions
● The 5 core principals that must never be violated
● Full spec: https://www.w3.org/Submission/viwi-protocol/
What is RSI?

● Multiple clients subscribe
● Any client or service can (policy based)
○ Create
○ Read
○ Update
○ Delete
○ Subscribe
● If subscribed, clients get notified in parallel
● at any given time clients can come and go
● no distributed state à single source of truth
12
Workflow example
Client 1 Client 2Service
TLS established
valid access_token(s) available
subscribe to event
subscribe acknowledge
initial state
subscribe acknowledge
initial state
subscribe to event
POST change
acknowledge a change
update stateupdate state
verify permission

● 3rd party service interested in vehicles entering geo-fence
● geofenceObject is created and subscribed by the 3rd party
● geofenceObject is updated in the when vehicles enter and
leave server side
● 3rd party receives notification on enter and leave
● 3rd party can access additional information for as long a
vehicle is within geofence
Use case – Send notifications based on geo-fence

● automatically buy Insurance coverage when
leaving/entering a country
● pay for congestion charges for the time a car
was in a particular zone
● paying tolls on bridges
● notify the vehicle owner of a car entering or
leaving a fence
● integrate with home automation to switch on
heating or lights when entering the vicinity
Use Cases for geofences

quote: https://azure.microsoft.com/en-us/overview/what-is-serverless-computing/
“Serverless computing enables developers to build applications faster by eliminating the need for them to
manage infrastructure. With serverless applications, the cloud service provider automatically provisions,
scales and manages the infrastructure required to run the code.“
● shutdown after a certain time automatically, thus need to be run stateless
● Function-as-a-Service (FaaS)
Of course servers are still running the code ;)
What is serverless ?
image source: https://www.botmetric.com/blog/what-is-serverless-computing/

● serverless charges in units of execution time (100ms)
● triggering many functions with short runtime turns out costly
● pay for less units when combining calls
● combine POSTs back to API Gateway in a single call close
to al low multiple of 100ms of runtime – not minutes
○ downside: parallelization of message delivery is limited
○ need to find sweet spot between cost and latency
○ serverless functions are designed to be short lived, do not run
tasks “forever”
Lessons learned using serverless
billed 5 units
billed 2 units

based on https://serverless.com/blog/api-gateway-websockets-example/
● API Gateway holds connections to millions
● serverless function invoke upon connection, handle stored
● ‘events’ capable database invokes functions on change
● serverless function POSTs back on connection handle
● clients receive messages
● system sleeps when idle
Implementing RSI on top of serverless

● geospatial capabilities
● big documents
● terra-bytes of journey logs - already today
● peta-bytes of vehicle data in future
● events for real-time
make MongoDB the heart
● 2 hosting options
○ host yourself (cloud agnostic)
○ utilize Atlas
è ONE solution supports all use cases

An actual subscription message and its response
{
"type": "subscribe",
"event": "/notificationmanager/notifications/",
"Authorization": "eyJhbGciOiJIUzI1NiIsInR5cCI6I
kpXVCJ9.eyJtZXNzYWdlIjoieW91IGRpZCBub3QgcmVhbGx5I
GV4cGVjdGVkIGEgdG9rZW4sIGRpZCB5b3U_In0.iCGo2OwyV-
H4FElp6VGuWIfs4ee3damtgFUy6IWj_VI"
}
{
"status": "ok",
"type": "subscribe",
"event": "/notificationmanager/notifications/"
}
{
"type": "data",
"status": "ok",
"data": [{
"content": “low on washer fluid",
"id": "3bebf144-856e-413f-8cb6-ffdbc9e56d59",
"name": "Maintenance",
"title": "Maintenance needed!",
"uri": "/notificationmanager/notifications/
3bebf144-856e-413f-8cb6-ffdbc9e56d59"
}],
"event": "/notificationmanager/notifications/"
}
ws:// Subscription including Authorization ws:// Acknowledgement and initial data 2-Frames

● model resembles the RSI subscribe message
● adds wsConnectionId for POST backs
● adds lastUpdatedFields for quicker diffs
○ compare wsConnectionId against filters
Data model for storing subscriptions
import { Schema } from "mongoose";
export const subscriptionSchema = new Schema({
wsConnectionId: {
type: String,
required: true
},
event: {
type: String,
required: true,
validate: /^/w+/w+/(:?[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-
F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12})?$/
},
filters: [{
field: {
type: String,
required: true
},
criteria: {
type: String,
required: true
}
}],
lastUpdatedFields: [
{
type: String,
required: true
}
],
updateLimit: Number,
interval: Number
}, {
autoIndex: false
});

● index on wsConnectionId to quickly fetch all events for a
particular subscriber
○ used when revoking all subscriptions for a given
wsConnectionId
○ used when reauthorizing all subscriptions for a given
wsConnectionId
● index on event to quickly fetch all subscribers for a
particular RSI event
○ used to notify all subscribers on a particular event
● filtering is done in the lambda as of today..
optimization possible
○ notify only those subscriber who are interested in the fields
modified last
Using indexes
wsConnectionId _id
event _id
_id event wsConnectionId …
index #1
index #2
subscriptions

● actual content in different collection
○ might be integrated later to avoid separate query
● subscriptions on resource level
○ one emits every hour independent of change
using proprietary scheduler
● subscriptions on element level
○ d65… was modified after subscription
● none of the subscription filtered
well spotted "__v", we are using mongoose 😜"
Example Notifications Collection
[
{
"lastUpdatedFields": ["body“, "lastmodified"],
"_id": "5d7a89c45e049808ece777d6",
"wsConnectionId": "bXU72eVToAMCFow=",
"event": "/notificationmanager/notifications/d65a1847-528d-4cb7-9795-b19f32dbc76f",
"filters": [],
"__v": 1
},
{
"lastUpdatedFields": [],
"_id": "5d7a89c45e049808ece777d7",
"event": "/notificationmanager/notifications/36054d10-e5f1-4a2a-8e62-e72cc9d71e7c",
"filters": [],
"__v": 0
},
{
"_id": "5d7a89c45e049808ece777d8",
"filters": [],
"interval": 3600000,
"__v": 0
},
{
"_id": "5d7a89c45e049808ece777d9",
"wsConnectionId": "f6liYf5WIAMCFLg=",
"event": "/notificationmanager/notifications/41503229-d2ce-4aa7-ac43-1b62f4e06cb0",
"filters": [],
"__v": 0
},
{
"lastUpdatedFields": ["body“, "lastmodified"],
"_id": "5d7a89c45e049808ece777da",
"event": "/notificationmanager/notifications/d65a1847-528d-4cb7-9795-b19f32dbc76f",
"filters": [],
"__v": 1
},
{
"_id": "5d7a89c45e049808ece777dc",
"filters": [],
"__v": 0
}
]

How did we arrive at this setup?
● we were using non-standard protocols
○ missing design guidelines led to fragmentation
○ APIs were hard to consume for clients
● our servers had to hold the WebSocket connections
themselves
○ hard to scale
○ expensive in idle mode
● we had different databases solutions for different
purposes
○ hard to scale
○ secure the platform
○ had to take care of partitioning
to the rescue

Demo
Most Impressive: all the way through the system in milliseconds !!!

● nice connected cars:
○ Jaguar https://www.jaguar.com/
○ Land Rover https://www.jaguar.com/
● good to reads
○ Mongo Change Events https://docs.mongodb.com/manual/reference/change-events/
○ API Gateway https://serverless.com/blog/api-gateway-websockets-example/
○ RSI specification: https://www.w3.org/Submission/viwi-protocol/
○ serverless: https://www.botmetric.com/blog/what-is-serverless-computing
● Open Source
○ https://github.com/wzr1337
If you want to learn more…

MongoDB .local London 2019: The Tech Behind Connected Car

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