[
https://issues.apache.org/jira/browse/AMQ-7045?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16613773#comment-16613773
]
Christopher L. Shannon commented on AMQ-7045:
---------------------------------------------
[~da4id] - I think this change is ok but you might want to include a unit test
or 2 to the MQTT tests to validate the change.
[~dejanb] - does this change look ok to you?
> Lost messages when send from amq to mqtt client
> -----------------------------------------------
>
> Key: AMQ-7045
> URL: https://issues.apache.org/jira/browse/AMQ-7045
> Project: ActiveMQ
> Issue Type: Bug
> Affects Versions: 5.15.3
> Environment: h1.
> Reporter: David Z.
> Priority: Major
> Fix For: 5.16.0
>
> Attachments: patchfile.txt
>
>
> We use a Java Tomcat application which publish / subscribe jms messages to
> Active mq and a Android Mobile application which is connected via mqtt to
> amq. When a Mobile client lost its connection in some case persistent
> messages get lost. I observerved this behavoiur with different mqtt clients.
> Here are two cases to reproduce this bug.
> h1. Case 1
> Two clients: Client A connected over mqtt and Client B connected via jms
> # Client A Subscribe to amq topic with Qos 2 and cleanSession = false
> # Client B publish Message to topic with persistant flag = true
> # Client A receive Message with Qos 0
> # Disconnect client A (Turn on Airplanemode on Android)
> # same as in step 2
> # wait several minutes (longer as keep alive intervall)
> # same as step 2
> # Connect client A again (Turn off Airplane mode on Android device)
> # Client A reiceives only message sent in step 7 with Qos = 0, message from
> step 5 is lost.
> h1. Case 2
> See
> [https://stackoverflow.com/questions/27189086/activemq-lost-persistent-message-sent-to-detached-consumer-before-keepaliveinter/52096122#52096122]
> h1. Expected Behavoiur
> Messages with persisant flag = true will sent to mqtt client with qos = 1 or
> 2 (delivered at least once or exactly once)
> Messages with persistant flag = false will sent to mqtt client with qos = 0
> (delivered 0 or 1 time)
> h1. Bug
> For me it seems that in File MQTTProtocolConverter on line 588 the constants
> QoS.AT_MOST_ONCE and QoS.AT_LEAST_ONCE are swapped.
> The line should look like
> {{qoS = message.isPersistent() ? QoS.AT_LEAST_ONCE : QoS.AT_MOST_ONCE ;}}
> instead of
> {{qoS = message.isPersistent() ? QoS.AT_MOST_ONCE : QoS.AT_LEAST_ONCE;}}
> A nice feature is when the user can change the mapping between Qos and
> Persistant Flag in the configuration file.
> [https://git-wip-us.apache.org/repos/asf?p=activemq.git;a=blob;f=activemq-mqtt/src/main/java/org/apache/activemq/transport/mqtt/MQTTProtocolConverter.java;h=ff6ee4335a4d27d665d4012f3b85c0ea3b31cfc2;hb=HEAD]
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
