Hi Erik, We use retained messages and have observed that very behavior. We needed every new joining client to receive the full system state (retained messages from both broker A and broker B).
What we did to achieve that was go to a single active broker and a standby broker. Retained messages with QoS 1 & 2 are replicated to the standby broker if you are using Replication. If you are using QoS = 0, then those messages are considered not durable by the broker and they are not replicated to the standby broker instance. If you are using Shared Store they will be there because of the shared disk. Best Regards, Paul From: Devriendt, Erik <erik.devrie...@siemens.com.INVALID> Date: Wednesday, May 8, 2024 at 4:57 AM To: users@activemq.apache.org <users@activemq.apache.org> Subject: MQTT retained messages and federation Hello all I have a question about retained messages in MQTT. I have 2 federated activeMQ Artemis 2.32.0 brokers A and B. When I start a MQTT client on broker A that publishes a retained message on a given topic and then exits, a second MQTT subscriber client started later and connected to that same broker does receive the retained message. However, a MQTT subscriber client connecting to broker B does not receive the retained message. It does receive messages when the publishing client on broker A is actively publishing messages. Is this known behavior? Is there a way to provide the retained message also to late subscribers on broker B?
