Author here. This came out of a production OOM in a clustered MQTT broker. The main lesson was that we had been treating different kinds of distributed state as though they all required the same consistency guarantee. Happy to discuss the incident, the ownership model, or the design trade-offs.
MQTT is a lightweight publish/subscribe protocol commonly used for IoT. Devices publish messages to topics through a broker, and subscribers receive messages from the topics they follow. Keel MQTT Gateway is the clustered MQTT broker discussed in the article
Author here. This came out of a production OOM in a clustered MQTT broker. The main lesson was that we had been treating different kinds of distributed state as though they all required the same consistency guarantee. Happy to discuss the incident, the ownership model, or the design trade-offs.
Indeed, one should choose the the lowest consistency guaranties that are required - to favor scalability and availability.
Some more thoughts on minimum requirements for a read-after-write consistency: https://software.mihvoi.ro/2026/04/2-flow-consistency-read-y...
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I like the article. Well written with a point made. Thanks
Thanks! Really glad you enjoyed it and that the main point came through clearly.
What is MQTT ?
MQTT is a lightweight publish/subscribe protocol commonly used for IoT. Devices publish messages to topics through a broker, and subscribers receive messages from the topics they follow. Keel MQTT Gateway is the clustered MQTT broker discussed in the article