[APLO-353] MQTT QoS always downgraded to 0

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Do
• Affects Version/s: 1.6
• Component/s: apollo-mqtt
• Labels: qos
• Environment: Mac OS X
• Assignee: Unassigned
• Reporter: Eric Cheung
• Created: 12/Mar/14 15:05
• Updated: 06/Apr/22 19:16
• Resolved: 06/Apr/22 19:16

Description

When subscriber subscribes with qos=2, and publisher sends PUBLISH with qos=2, Apollo changes it to qos=0 when sends to subscriber.

Publisher Apollo Subscriber

<-- SUBSCRIBE with qos=2
--> SUBACK

PUBLISH qos=2 --> --> PUBLISH qos=0
PUBREC <--
PUBREL -->
PUBCOMP <--

This is observed in the MqttQosTest test case. The assertion:

38 should_receive("1", topic)

does not actually test the qos level received. However, I looked at packet capture and confirmed that in the qos/EXACTLY_ONCE/EXACTLY_ONCE case, the PUBLISH was downgraded from qos=2 to qos=0 when it goes through Apollo.

(previously reported on mailing list on Feb 5, 2014)