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https://issues.apache.org/jira/browse/AMQ-6784?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Tomas Pavelka updated AMQ-6784:
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Attachment: HubAndSpokeDuplicateMessages.java
The unit test reproduces the problem in ActiveMQ 5.13.2 and also demonstrates
the workaround.
> Duplicate messages received in hub and spoke topology
> -----------------------------------------------------
>
> Key: AMQ-6784
> URL: https://issues.apache.org/jira/browse/AMQ-6784
> Project: ActiveMQ
> Issue Type: Bug
> Components: Broker
> Affects Versions: 5.13.2
> Reporter: Tomas Pavelka
> Priority: Minor
> Attachments: HubAndSpokeDuplicateMessages.java
>
>
> If there are multiple consumers of a single topic in a hub and spoke topology
> where each of the spokes has an embedded broker, then each of the consumers
> receives one message sent to the topic multiple times.
> The topology looks like this:
> Spoke (broker) -> Hub (broker) <- Spoke (broker)
> ^
> Spoke (broker)
> If one spoke sends a message to a topic and at least two other spokes have
> consumers then they will receive the message multiple times.
> The likely cause is that
> org.apache.activemq.network.ConduitBridge#addToAlreadyInterestedConsumers
> checks if the incoming ConsumerInfo represents a network subscription
> in the topology used it does because the subscription info is passed through
> two brokers
> There exists a workaround: if any policy is applied to the destination then
> duplication does not happen. This is because PolicyEntry#enableAudit is true
> by default and is applied to
> org.apache.activemq.broker.region.BaseDestination#enableAudit which is false
> by default.
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