| # Message Group Example |
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| If you have not already done so, [prepare the broker distribution](../../../../README.md#getting-started) before running the example. |
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| To run the example, simply type **mvn verify** from this directory, or **mvn -PnoServer verify** if you want to start and create the broker manually. |
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| This example shows you how to configure and use message groups via a connection factory with ActiveMQ Artemis. |
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| Message groups are sets of messages that has the following characteristics: |
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| * Messages in a message group share the same group id, i.e. they have same JMSXGroupID string property values. |
| * Messages in a message group will be all delivered to no more than one of the queue's consumers. The consumer that receives the first message of a group will receive all the messages that belongs to the group. |
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| You can make any message belong to a message group by setting a 'group-id' on the connection factory. All producers created via this connection factory will set that group id on its messages. In this example we set the group id 'Group-0'on a connection factory and send messages via 2 different producers and check that only 1 consumer receives them. |
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| Alternatively, ActiveMQ's connection factories can be configured to _auto group_ messages. By setting `autoGroup=true` in the client's URL a random unique id will be picked to create a message group. _Every messages_ sent by a producer created from this connection factory will automatically be part of this message group. |
