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MQTT Retained Messages and Last Will Explained (with a .NET Demo)
October 31, 2026
Mastering .NET & Distributed Architecture
Advanced C# tutorials, system design deep-dives, and real-world developer tools built in public.
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mqtt-churn: an MQTT presence stress-test tool
An open-source .NET tool, built one episode at a time. It simulates fleets of MQTT clients, each with a Last Will, and measures what a broker does under churn: connect latency first, then how long it takes to tell everyone a client has died.
.NET 10
MQTTnet
MQTT 5
Mosquitto
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MQTT Retained Messages and Last Will Explained (with a .NET Demo)
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MQTT Retained Messages and Last Will Explained (with a .NET Demo)
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Written by Romain Ottonelli Dabadie, .NET engineer. Messaging, distributed systems and the architecture decisions that still hold up two years later. More about me.