The new release of Bosch IoT Hub, part of Bosch IoT Device Management, comes with the following improvements:
Changes to error handling behavior of MQTT adapter
The new release of Bosch IoT Hub introduces changes to the MQTT adapter's error handling behavior. Until now, the adapter kept the connection to the device open in case of non-terminal errors. When a device has subscribed for error-topics, an error message on the error topic was sent, the error itself was ignored and a PUBACK for the message that caused the error was sent.
As of this release, when a device publishes a telemetry, event or command response message and there is an error when processing the message, the handling of the error depends on whether there is an error topic subscription for the device and whether an on-error property bag parameter was set on the topic used for sending the message. If no error subscription is in place and no on-error parameter was set, the default error handling behavior is to close the MQTT connection to the device. If the device has a subscription on the error topic (on the same MQTT connection the device uses for sending messages), the default behavior is to keep the MQTT connection open unless a terminal error happens. See the errors that are classified as terminal here.
Please consider the upcoming changes and configure your devices in an appropriate manner to achieve the expected and desired behavior by error handling.