(Kai Waehner, Confluent) Kafka Summit SF 2018 This session discusses end-to-end use cases such as connected cars, smart home or healthcare sensors, where you integrate Internet of Things (IoT) devices with enterprise IT using open source technologies and standards. MQTT is a lightweight messaging protocol for IoT. However, MQTT is not built for high scalability, longer storage or easy integration to legacy systems. Apache Kafka is a highly scalable distributed streaming platform, which ingests, stores, processes and forwards high volumes of data from thousands of IoT devices. This session discusses the Apache Kafka open source ecosystem as a streaming platform to process IoT data. See a live demo of how MQTT brokers like Mosquitto or RabbitMQ integrate with Kafka, and how you can even integrate MQTT clients to Kafka without MQTT Broker. Learn how to analyze the IoT data either natively on Kafka with Kafka Streams/KSQL or on an external big data cluster like Spark, Flink or Elasticsearch leveraging Kafka Connect.

1. 1Confidential
Processing IoT Data with
MQTT and Apache Kafka
Kai Waehner
Technology Evangelist
kontakt@kai-waehner.de
LinkedIn
@KaiWaehner
www.confluent.io
www.kai-waehner.de
Kafka-Native End-to-End IoT Data Integration and Processing

2. 3
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

3. 4
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

4. 6
Connected Intelligence (Cars, Machines, Robots, …)

5. 7
Smart Cities

6. 8
Smart Retail and Customer 360

7. 9
Intelligent Applications (Early Part Scrapping, Predictive Maintenance, …)

8. 10
?
Architecture (High Level)
Kafka BrokerKafka BrokerStreaming
Platform
Connect
w/ MQTT
connector
IoT
Gateway
DevicesDevicesDevicesDevice
Device Tracking
(Real Time)
Predictive
Maintenance
(Near Real Time)
Log Analytics
(Batch)
Edge Data Center / Cloud
How to integrate?

9. 11
Poll
Which IoT scenarios do you see in your company?
1) IoT ingestion into analytics cluster
2) Bi-directional communication to control IoT devices
(e.g. connected cars, fleet management, logistics)
3) Real time stream processing using machine learning
(e.g. predictive maintenance, early part scrapping)
4) No IoT scenarios today; maybe in the future

10. 13
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

11. 14
MQTT - Publish / subscribe messaging protocol
• Built on top of TCP/IP for constrained devices and unreliable networks
• Many (open source) broker implementations
• Many client libraries
• IoT-specific features for bad network / connectivity
• Widely used (mostly IoT, but also web and mobile apps via MQTT over WebSockets)

12. 15
MQTT
Server 1
Processor 1 Processor 2 ...
MQTT Architecture (no scale)
topic: [deviceid]/car

13. 16
MQTT
Server
Coordinator
MQTT
Server 1
MQTT
Server 2
MQTT
Server 3
MQTT
Server 4
topic: [deviceid]/car
...
MQTT Architecture (clustering depends on broker implementation)
Processor
1
Processor
2
Processor
3
Processor
4

14. 17
MQTT Architecture (clustering depends on broker implementation)
Load
Balancer
MQTT
Server 1
MQTT
Server 2
MQTT
Server 3
MQTT
Server 4
topic: [deviceid]/car
...
Processor
1
Processor
2
Processor
3
Processor
4

15. 18
MQTT Trade-Offs
Pros
• Lightweight
• Simple API
• Built for poor connectivity / high latency scenario
• Many client connections (tens of thousands per MQTT server)
Cons
• Queuing, not stream processing
• Can’t handle usage surges (no buffering)
• No high scalability
• Very asynchronous processing (often offline for long time)
• No good integration to rest of the enterprise
• No reprocessing of events

16. 19
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

17. 20
Apache Kafka – The Rise of a Streaming Platform
The Log ConnectorsConnectors
Producer Consumer
Streaming Engine

18. 24
Apache Kafka == Distributed Commit Log with Replication

19. 26
Kafka Trade-Offs (from IoT perspective)
Pros
• Stream processing, not just queuing
• High throughput
• Large scale
• High availability
• Long term storage and buffering
• Reprocessing of events
• Good integration to rest of the enterprise
Cons
• Not built for tens of thousands connections
• Requires stable network and good infrastructure
• No IoT-specific features like keep alive, last will or testament

20. 27
(De facto) Standards for Processing IoT Data
A Match Made In Heaven
+ =

21. 28
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

22. 29
?
Architecture (High Level)
Kafka BrokerKafka BrokerStreaming
Platform
Connect
w/ MQTT
connector
GatewayDevicesDevicesDevicesDevice
Device Tracking
(Real Time)
Predictive
Maintenance
(Near Real Time)
Log Analytics
(Batch)
Edge Data Center / Cloud
How to integrate?

23. 30
MQTT
Server
Coordinator
MQTT
Server 1
MQTT
Server 2
MQTT
Server 3
MQTT
Server 4
topic: [deviceid]/car
Kafka Integration
Sensor Data
Stream
processing
Kafka Cluster
End-to-End Integration from MQTT to Apache Kafka

24. 31
Design Questions for End-to-End Integration
• How much throughput?
• Ingest-only vs. processing of data?
• Analytical vs. operational deployments?
• Device publish only vs. device pub/sub?
• Pull vs. Push?
• Low-level client vs. integration framework vs. proxy?
• Integration patterns needed? (transform, route, …)?
• IoT-specific features required (last will, testament, …)?

25. 32
Kafka-Native Integration Options between MQTT and Apache Kafka
Kafka Connect
MQTT Proxy
REST Proxy

26. 33
Kafka-Native Integration Options between MQTT and Apache Kafka
Kafka Connect
MQTT Proxy
REST Proxy

27. 34
MQTT Source and Sink Connectors for Kafka Connect
https://www.confluent.io/hub/
https://www.confluent.io/connector/kafka-connect-mqtt/

28. 35
?
Integration with Kafka Connect (Source and Sink)
Kafka BrokerKafka BrokerKafka Broker
MQTT
Broker
Connect
w/ MQTT
connector
Connect
w/ MQTT
connectorMQTT
DevicesDevicesDevicesDevice
Kafka
Consumer
MQTT Broker
Persistent + offers MQTT-specific features
Consumes push data from IoT devices
Kafka Connect
Kafka Consumer + Kafka Producer under the hood
Pull-based (at own pace, without overwhelming the source or getting overwhelmed by the source)
Out-of-the-box scalability and integration features (like connectors, converters, SMTs)

29. 38
Kafka Connect components

30. 39
Connector for MQTT Source + Single Message Transformation (SMT)
curl -s -X POST -H 'Content-Type: application/json' http://localhost:8083/connectors -d '{
"name" : "mqtt-source",
"config" : {
"connector.class" : "io.confluent.connect.mqtt.MqttSourceConnector",
"tasks.max" : "1",
"mqtt.server.uri" : "tcp://127.0.0.1:1883",
"mqtt.topics" : "temperature",
"kafka.topics" : "mqtt.",
"transforms":"filter",
"transforms.filter.type":"com.github.kaiwaehner.kafka.connect.smt.StringFilter",
"transforms.filter.topic.format":"fraud"
}
}'

31. 40
Kafka Connect - Converters
MQTT
Broker
S3
Object
Storage
MQTT Source
Connector
AvroConverter
AvroConverter
S3 Sink
Connector
JSON
Message
Connect data
API format
byte[]
(Avro)
byte[]
(Avro)
Connect data
API format
AmazonS3
Object

32. 41
Live Demo
… MQTT Integration with Kafka Connect…
Connect

33. 42
Kafka Connect + MQTT Connector
https://github.com/kaiwaehner/kafka-connect-iot-mqtt-connector-example

34. 43
Kafka-Native Integration Options between MQTT and Apache Kafka
Kafka Connect
MQTT Proxy
REST Proxy

35. 44
MQTT Proxy
Kafka BrokerKafka BrokerKafka Broker
MQTT
ProxyMQTT
DevicesDevicesDevicesDevices
Kafka
Consumer
MQTT Proxy
MQTT is push-based
Horizontally scalable
Consumes push data from IoT devices and forwards it to Kafka Broker at low-latency
Kafka Producer under the hood
No MQTT Broker needed
Kafka Broker
Source of truth
Responsible for persistence, high availability, reliability

36. 45
Details of Confluent’s MQTT Proxy Implementation
General and modular framework
• Based on Netty to not re-invent the wheel (network layer handling, thread pools)
• Scalable with standard load balancer
• Internally uses Kafka Connect formats (allows re-using transformation and other Connect-
constructs à Coming soon)
Three pipeline stages
• Network (Netty)
• Protocol (like MQTT with QoS 0,1,2 today, later others, maybe e.g. WebSockets)
• Stream (Kafka clients: Today Producers, later also consumers)
Missing parts in first release
• Only MQTT Publish; MQTT Subscribe coming soon
• MQTT-specific features like last will or testament

37. 46
Kafka-Native Integration Options between MQTT and Apache Kafka
Kafka Connect
MQTT Proxy
REST Proxy

38. 47
Confluent REST Proxy
REST Proxy
Non-Java
Applications
Native Kafka Java
Applications
Schema Registry
REST / HTTP(S)
TCP
The „simple alternative“ for IoT
• Simple and understood
• HTTP(S) Proxy à Push-based
• Security ”easier”
• Scalable with standard load balancer
(still synchronous HTTP)
• Not for very high throughput
• Implement Connect features in your
client app

39. 48
Confluent REST Proxy - Produce and Consume Messages

40. 49
Agenda
1) IoT Use Cases
2) MQTT Standard
3) Apache Kafka Ecosystem
4) Kafka-Native End-to-End IoT Integration Architecture(s)
5) IoT Data Processing

41. 5050
Processing Options for MQTT Data with Apache Kafka
Streams
Kafka native vs. additional big data cluster and technology
(or others, you name it …)

42. 5353
Example: Anomaly Detection System to Predict Defects in Car Engine
MQTT
Proxy
Elastic
search
Grafana
Kafka
Cluster
Kafka
Connect
KSQL
Car Sensors
Kafka Ecosystem
Other Components
Real Time
Emergency
System
All Data
PotentialDefect
Apply
Analytic
Model
Filter
Anomalies
On premise DC: Kubernetes + Confluent OperatorAt the edge

43. 5454
KSQL and Deep Learning (Auto Encoder) for Anomaly Detection
“CREATE STREAM AnomalyDetection AS
SELECT sensor_id, detectAnomaly(sensor_values)
FROM car_engine;“
User Defined Function (UDF)

44. 55
Live Demo
… Processing IoT data with MQTT Proxy and KSQL …

45. 56
Deep Learning UDF for KSQL for Streaming Anomaly Detection of MQTT IoT Sensor Data
https://github.com/kaiwaehner/ksql-udf-deep-learning-mqtt-iot

46. 57
Poll
What is the best choice for your IoT integration between MQTT and Kafka?
1. Kafka Connect
2. MQTT Proxy
3. REST Proxy
4. Custom Kafka Client
(Java Client, Nifi, StreamSets, non-MQTT technology, …)

47. 58
Kai Waehner
Technology Evangelist
kontakt@kai-waehner.de
@KaiWaehner
www.kai-waehner.de
www.confluent.io
LinkedIn
Questions? Feedback?
Please contact me!