[AMQ-5185] Duplicate messages occur for MQTT cleanSession=false client with network of brokers

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 5.9.1
• Component/s: MQTT
• Labels: close-pending mqtt

Environment

Linux. Python client using MQTT Paho library version 0.9

• Assignee: Matt Pavlovich
• Reporter: Paddy
• Created: 14/May/14 23:13
• Updated: 06/Dec/20 02:16

Description

Duplicates delivery of messages occur when connecting to a network of brokers with an MQTT client with cleansession=false.
Steps to reproduce test:
1. Form network of brokers A and B
2. Connect "client1" with cleansession=false to broker A and subscribe to topic "paho/test". Make sure client_id is set to "client1".
3. Disconnect client1
4. Connect "client2" to broker A and publish single message "hello" to topic "paho/test".
5. Connect "client1" to broker A and subscribe to "paho/test". Message "hello" would be received.
6. Disconnect "client1"
7. Connect "client1" to broker B and subscribe to "paho/test". Message "hello" would be received (again).

Behavior is the same for publishing with qos=0,1,2.

Issue Links

• relates to: AMQ-5290 MQTT clients using durable subscriptions on networked brokers received duplicates