Eclipse Hono 0.8 Release Review

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This release concludes the integration of the Command & Control functionality that has been introduced as a Technology Preview in Hono 0.6. In particular

  • the Command & Control API has been extended with an operation for sending one-way commands to devices
  • the AMQP protocol adapter now also supports the Command & Control functionality

Hono now uses Micrometer for reporting metrics to arbitrary backend. With this change, Hono now consistently makes use of tags in the metrics which can be used to more easily filter and aggregate metrics in dashboards.

Hono 0.8 switched to use Java 11 for container images. However Hono 0.8 will still stick to Java 8 source and target compatiblity. Unit and integration tests will also be run on both Java 8 and Java 11. Java 9 and 10 are neither tested nor supported.

Architectural Issues

A lot of work has gone into extending/changing the standard MQTT protocol adapter to support the Eclipse IoT Namespace defined in the Eclipse IoT Integration working group. The overall goal of this work is to allow Hono being used as the connectivity layer in Eclipse Kapua. A first demonstration of this has been given at EclipseCon Europe 2018. However, there is still some work to be done in Kapua to also support sending commands to devices via Hono. Nevertheless, it is now possible to connect Eclipse Kura 4.0.0 based gateways to Hono's standard MQTT adapter using Kura's Eclipse IoT Cloud Connector.

Security Issues

The strength of BCrypt based password hashes can now be limited by means of a configuration property in order to prevent DoS attacks conducted by registering credentials using very strong hashes. 

Conforms To UI/UX Guidelines
Not verified
End of Life

We are not (yet) removing the Kura Protocol Adapter component altogether from Hono. However, we are deprecating it with this release and we are encouraging users to upgrade their Kura based gateways to version 4.0.0 and connect them to the standard MQTT adapter instead.


This release implements Eclipse IoT namespace agreed upon by Kura, Kapua and Hono. One exception to that is the alert messages, which are currently not implemented.


We are very happy with the progress being made with the integration of Hono with Eclipse Kapua. As a result, we expect Kapua 1.1 being able to employ Hono as its device connectivity layer in the very near future.