Posted On: Aug 22, 2019
Starting today, Amazon IoT customers can configure the quality of service (QoS) when publishing messages via the republish action of a topic rule. Amazon IoT supports QoS levels 0 and 1 for MQTT messages, where QoS 0 means a message is delivered zero or more times and QoS 1 means message is delivered one or more times. See Amazon IoT MQTT documentation for more details about Amazon IoT QoS definition.
Previously, the republish action would publish messages as QoS 0. With the new ability to configure the QoS of messages published via the republish action, customers now have the option to publish their important messages as QoS 1 and have subscribers acknowledge the reception of these messages if they also subscribe as QoS 1. Furthermore, in combination with persistent sessions, QoS 1 publish messages will get queued if the subscriber is disconnected and will be delivered upon reconnection.
For more details about this feature, refer to the republish action documentation.