Video recording: https://www.youtube.com/watch?v=OTbpUbTO5_I A success story of using MQTT and Eclipse IoT components in DeltaRail's state-of-the-art signalling control system. Overview of the architecture, lessons learnt and best practises in using MQTT for highly reliable, high-throughput, low-latency messaging in a safety-related environment.

1. Running UK railway with
Eclipse Paho & Mosquitto
Presented by: Kamil Baczkowicz, September 2016

2. Agenda
Running UK railway with Eclipse Paho & Mosquitto 2
• Signalling in 60 seconds
• IECC Scalable
 Overview
 Architecture
• Eclipse IoT components
 Eclipse Paho (Java Client & mqtt-spy)
 Eclipse Mosquitto
• Lessons learnt & best practices

3. Running UK railway with Eclipse Paho & Mosquitto 3
• Tracks
• Signals
• Points (switches)
• Routes
• Interlockings
Signalling concepts

4. Running UK railway with Eclipse Paho & Mosquitto 4
Evolution of interlockings

5. IECC Scalable
Running UK railway with Eclipse Paho & Mosquitto 5

6. IECC Scalable architecture
Running UK railway with Eclipse Paho & Mosquitto 6
 High availability (99.9995%)
 Hardware & software
redundancy
 Low maintenance
 High-throughput &
low-latency messaging

7. Running UK railway with Eclipse Paho & Mosquitto 7
• Java Client
– Synchronous and asynchronous APIs
– Highly resilient
• mqtt-spy
– Simple pub/sub
– Advanced filtering & scripting
– Decoding custom message formats
• mqtt-spy-daemon
– Command line (no GUI)
– Aimed at automated testing
– XML configuration & Java API

8. Running UK railway with Eclipse Paho & Mosquitto 8
• Lightweight, production-grade MQTT
broker (server implementation of the
MQTT protocol)
• High throughput & low latency
messaging
• Since first deployment, over 20 000
hours of service without interruption

9. Lessons learnt & best practices
Running UK railway with Eclipse Paho & Mosquitto 9
• Pub/sub vs point-to-point
• QoS 0 (fire & forget) vs QoS 1&2 (persistent)
 Performance
 Maintenance
 Data loss & retry
• Payload compression (XML / JSON)
• Testability (intercepting & injecting)
• Test automation (functional & performance)