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| Introduction |
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| <b>1.</b> |
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| Legal Notice |
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| <li class="chapter " data-level="2" data-path="preface.html"> |
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| <b>2.</b> |
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| Preface |
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| <b>3.</b> |
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| Project Info |
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| <b>4.</b> |
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| Messaging Concepts |
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| <b>5.</b> |
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| Architecture |
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| <b>6.</b> |
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| Using the Server |
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| <a href="./using-jms.html"> |
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| <b>7.</b> |
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| Using JMS |
| </a> |
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| </li> |
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| <li class="chapter " data-level="8" data-path="using-core.html"> |
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| <a href="./using-core.html"> |
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| <b>8.</b> |
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| Using Core |
| </a> |
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| </li> |
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| <li class="chapter " data-level="9" data-path="jms-core-mapping.html"> |
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| <a href="./jms-core-mapping.html"> |
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| <b>9.</b> |
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| Mapping JMS Concepts to the Core API |
| </a> |
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| </li> |
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| <li class="chapter " data-level="10" data-path="client-classpath.html"> |
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| <a href="./client-classpath.html"> |
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| <b>10.</b> |
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| The Client Classpath |
| </a> |
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| </li> |
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| <li class="chapter " data-level="11" data-path="examples.html"> |
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| <b>11.</b> |
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| Examples |
| </a> |
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| <li class="chapter " data-level="12" data-path="wildcard-routing.html"> |
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| <a href="./wildcard-routing.html"> |
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| <b>12.</b> |
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| Routing Messages With Wild Cards |
| </a> |
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| </li> |
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| <li class="chapter " data-level="13" data-path="wildcard-syntax.html"> |
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| <a href="./wildcard-syntax.html"> |
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| <b>13.</b> |
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| Understanding the Apache ActiveMQ Artemis Wildcard Syntax |
| </a> |
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| </li> |
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| <li class="chapter " data-level="14" data-path="filter-expressions.html"> |
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| <a href="./filter-expressions.html"> |
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| <b>14.</b> |
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| Filter Expressions |
| </a> |
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| </li> |
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| <li class="chapter " data-level="15" data-path="persistence.html"> |
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| <a href="./persistence.html"> |
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| <b>15.</b> |
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| Persistence |
| </a> |
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| </li> |
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| <li class="chapter " data-level="16" data-path="configuring-transports.html"> |
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| <a href="./configuring-transports.html"> |
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| <b>16.</b> |
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| Configuring Transports |
| </a> |
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| </li> |
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| <li class="chapter " data-level="17" data-path="connection-ttl.html"> |
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| <a href="./connection-ttl.html"> |
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| <b>17.</b> |
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| Detecting Dead Connections |
| </a> |
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| </li> |
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| <li class="chapter " data-level="18" data-path="slow-consumers.html"> |
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| <a href="./slow-consumers.html"> |
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| <b>18.</b> |
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| Detecting Slow Consumers |
| </a> |
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| </li> |
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| <li class="chapter " data-level="19" data-path="transaction-config.html"> |
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| <a href="./transaction-config.html"> |
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| <b>19.</b> |
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| Resource Manager Configuration |
| </a> |
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| </li> |
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| <li class="chapter " data-level="20" data-path="flow-control.html"> |
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| <a href="./flow-control.html"> |
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| <b>20.</b> |
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| Flow Control |
| </a> |
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| </li> |
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| <li class="chapter " data-level="21" data-path="send-guarantees.html"> |
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| <a href="./send-guarantees.html"> |
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| <b>21.</b> |
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| Guarantees of sends and commits |
| </a> |
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| </li> |
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| <li class="chapter " data-level="22" data-path="undelivered-messages.html"> |
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| <a href="./undelivered-messages.html"> |
| <i class="fa fa-check"></i> |
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| <b>22.</b> |
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| Message Redelivery and Undelivered Messages |
| </a> |
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| </li> |
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| <li class="chapter " data-level="23" data-path="message-expiry.html"> |
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| <a href="./message-expiry.html"> |
| <i class="fa fa-check"></i> |
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| <b>23.</b> |
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| Message Expiry |
| </a> |
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| </li> |
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| <li class="chapter " data-level="24" data-path="large-messages.html"> |
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| <a href="./large-messages.html"> |
| <i class="fa fa-check"></i> |
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| <b>24.</b> |
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| Large Messages |
| </a> |
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| </li> |
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| <li class="chapter " data-level="25" data-path="paging.html"> |
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| <a href="./paging.html"> |
| <i class="fa fa-check"></i> |
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| <b>25.</b> |
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| Paging |
| </a> |
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| </li> |
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| <li class="chapter " data-level="26" data-path="queue-attributes.html"> |
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| <a href="./queue-attributes.html"> |
| <i class="fa fa-check"></i> |
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| <b>26.</b> |
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| Queue Attributes |
| </a> |
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| </li> |
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| <li class="chapter " data-level="27" data-path="scheduled-messages.html"> |
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| <a href="./scheduled-messages.html"> |
| <i class="fa fa-check"></i> |
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| <b>27.</b> |
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| Scheduled Messages |
| </a> |
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| </li> |
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| <li class="chapter " data-level="28" data-path="last-value-queues.html"> |
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| <a href="./last-value-queues.html"> |
| <i class="fa fa-check"></i> |
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| <b>28.</b> |
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| Last-Value Queues |
| </a> |
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| </li> |
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| <li class="chapter " data-level="29" data-path="message-grouping.html"> |
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| <a href="./message-grouping.html"> |
| <i class="fa fa-check"></i> |
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| <b>29.</b> |
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| Message Grouping |
| </a> |
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| </li> |
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| <li class="chapter " data-level="30" data-path="pre-acknowledge.html"> |
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| <a href="./pre-acknowledge.html"> |
| <i class="fa fa-check"></i> |
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| <b>30.</b> |
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| Extra Acknowledge Modes |
| </a> |
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| </li> |
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| <li class="chapter " data-level="31" data-path="management.html"> |
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| <a href="./management.html"> |
| <i class="fa fa-check"></i> |
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| <b>31.</b> |
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| Management |
| </a> |
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| </li> |
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| <li class="chapter " data-level="32" data-path="security.html"> |
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| <a href="./security.html"> |
| <i class="fa fa-check"></i> |
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| <b>32.</b> |
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| Security |
| </a> |
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| </li> |
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| <li class="chapter " data-level="33" data-path="resource-limits.html"> |
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| <a href="./resource-limits.html"> |
| <i class="fa fa-check"></i> |
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| <b>33.</b> |
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| Resource Limits |
| </a> |
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| </li> |
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| <li class="chapter " data-level="34" data-path="jms-bridge.html"> |
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| <a href="./jms-bridge.html"> |
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| <b>34.</b> |
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| The JMS Bridge |
| </a> |
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| </li> |
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| <li class="chapter " data-level="35" data-path="client-reconnection.html"> |
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| <a href="./client-reconnection.html"> |
| <i class="fa fa-check"></i> |
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| <b>35.</b> |
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| Client Reconnection and Session Reattachment |
| </a> |
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| </li> |
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| <li class="chapter " data-level="36" data-path="diverts.html"> |
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| <a href="./diverts.html"> |
| <i class="fa fa-check"></i> |
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| <b>36.</b> |
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| Diverting and Splitting Message Flows |
| </a> |
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| </li> |
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| <li class="chapter " data-level="37" data-path="core-bridges.html"> |
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| <a href="./core-bridges.html"> |
| <i class="fa fa-check"></i> |
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| <b>37.</b> |
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| Core Bridges |
| </a> |
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| </li> |
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| <li class="chapter active" data-level="38" data-path="duplicate-detection.html"> |
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| <a href="./duplicate-detection.html"> |
| <i class="fa fa-check"></i> |
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| <b>38.</b> |
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| Duplicate Message Detection |
| </a> |
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| </li> |
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| <li class="chapter " data-level="39" data-path="clusters.html"> |
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| <a href="./clusters.html"> |
| <i class="fa fa-check"></i> |
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| <b>39.</b> |
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| Clusters |
| </a> |
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| </li> |
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| <li class="chapter " data-level="40" data-path="ha.html"> |
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| <a href="./ha.html"> |
| <i class="fa fa-check"></i> |
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| <b>40.</b> |
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| High Availability and Failover |
| </a> |
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| </li> |
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| <li class="chapter " data-level="41" data-path="graceful-shutdown.html"> |
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| <a href="./graceful-shutdown.html"> |
| <i class="fa fa-check"></i> |
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| <b>41.</b> |
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| Graceful Server Shutdown |
| </a> |
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| </li> |
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| <li class="chapter " data-level="42" data-path="libaio.html"> |
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| <a href="./libaio.html"> |
| <i class="fa fa-check"></i> |
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| <b>42.</b> |
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| Libaio Native Libraries |
| </a> |
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| </li> |
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| <li class="chapter " data-level="43" data-path="thread-pooling.html"> |
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| <a href="./thread-pooling.html"> |
| <i class="fa fa-check"></i> |
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| <b>43.</b> |
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| Thread management |
| </a> |
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| </li> |
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| <li class="chapter " data-level="44" data-path="logging.html"> |
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| <a href="./logging.html"> |
| <i class="fa fa-check"></i> |
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| <b>44.</b> |
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| Logging |
| </a> |
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| </li> |
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| <li class="chapter " data-level="45" data-path="rest.html"> |
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| <a href="./rest.html"> |
| <i class="fa fa-check"></i> |
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| <b>45.</b> |
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| REST Interface |
| </a> |
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| </li> |
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| <li class="chapter " data-level="46" data-path="embedding-activemq.html"> |
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| <a href="./embedding-activemq.html"> |
| <i class="fa fa-check"></i> |
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| <b>46.</b> |
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| Embedding Apache ActiveMQ Artemis |
| </a> |
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| </li> |
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| <li class="chapter " data-level="47" data-path="karaf.html"> |
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| <a href="./karaf.html"> |
| <i class="fa fa-check"></i> |
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| <b>47.</b> |
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| Apache Karaf |
| </a> |
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| </li> |
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| <li class="chapter " data-level="48" data-path="spring-integration.html"> |
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| <a href="./spring-integration.html"> |
| <i class="fa fa-check"></i> |
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| <b>48.</b> |
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| Spring Integration |
| </a> |
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| </li> |
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| <li class="chapter " data-level="49" data-path="aerogear-integration.html"> |
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| <a href="./aerogear-integration.html"> |
| <i class="fa fa-check"></i> |
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| <b>49.</b> |
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| AeroGear Integration |
| </a> |
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| </li> |
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| <li class="chapter " data-level="50" data-path="vertx-integration.html"> |
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| <a href="./vertx-integration.html"> |
| <i class="fa fa-check"></i> |
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| <b>50.</b> |
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| VertX Integration |
| </a> |
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| </li> |
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| <li class="chapter " data-level="51" data-path="intercepting-operations.html"> |
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| <a href="./intercepting-operations.html"> |
| <i class="fa fa-check"></i> |
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| <b>51.</b> |
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| Intercepting Operations |
| </a> |
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| </li> |
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| <li class="chapter " data-level="52" data-path="protocols-interoperability.html"> |
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| <a href="./protocols-interoperability.html"> |
| <i class="fa fa-check"></i> |
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| <b>52.</b> |
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| Protocols and Interoperability |
| </a> |
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| </li> |
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| <li class="chapter " data-level="53" data-path="tools.html"> |
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| <a href="./tools.html"> |
| <i class="fa fa-check"></i> |
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| <b>53.</b> |
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| Tools |
| </a> |
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| </li> |
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| <li class="chapter " data-level="54" data-path="maven-plugin.html"> |
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| <a href="./maven-plugin.html"> |
| <i class="fa fa-check"></i> |
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| <b>54.</b> |
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| Maven Plugin |
| </a> |
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| |
| </li> |
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| <li class="chapter " data-level="55" data-path="perf-tuning.html"> |
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| <a href="./perf-tuning.html"> |
| <i class="fa fa-check"></i> |
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| <b>55.</b> |
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| Troubleshooting and Performance Tuning |
| </a> |
| |
| |
| |
| </li> |
| |
| <li class="chapter " data-level="56" data-path="configuration-index.html"> |
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| <a href="./configuration-index.html"> |
| <i class="fa fa-check"></i> |
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| <b>56.</b> |
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| Configuration Reference |
| </a> |
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| </li> |
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| <li> |
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| Published with GitBook |
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| <h1> |
| <i class="fa fa-circle-o-notch fa-spin"></i> |
| <a href="./" >ActiveMQ Artemis Documentation</a> |
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| <section class="normal" id="section-"> |
| |
| <h1 id="duplicate-message-detection">Duplicate Message Detection</h1> |
| <p>Apache ActiveMQ Artemis includes powerful automatic duplicate message detection, |
| filtering out duplicate messages without you having to code your own |
| fiddly duplicate detection logic at the application level. This chapter |
| will explain what duplicate detection is, how Apache ActiveMQ Artemis uses it and how |
| and where to configure it.</p> |
| <p>When sending messages from a client to a server, or indeed from a server |
| to another server, if the target server or connection fails sometime |
| after sending the message, but before the sender receives a response |
| that the send (or commit) was processed successfully then the sender |
| cannot know for sure if the message was sent successfully to the |
| address.</p> |
| <p>If the target server or connection failed after the send was received |
| and processed but before the response was sent back then the message |
| will have been sent to the address successfully, but if the target |
| server or connection failed before the send was received and finished |
| processing then it will not have been sent to the address successfully. |
| From the senders point of view it's not possible to distinguish these |
| two cases.</p> |
| <p>When the server recovers this leaves the client in a difficult |
| situation. It knows the target server failed, but it does not know if |
| the last message reached its destination ok. If it decides to resend the |
| last message, then that could result in a duplicate message being sent |
| to the address. If each message was an order or a trade then this could |
| result in the order being fulfilled twice or the trade being double |
| booked. This is clearly not a desirable situation.</p> |
| <p>Sending the message(s) in a transaction does not help out either. If the |
| server or connection fails while the transaction commit is being |
| processed it is also indeterminate whether the transaction was |
| successfully committed or not!</p> |
| <p>To solve these issues Apache ActiveMQ Artemis provides automatic duplicate messages |
| detection for messages sent to addresses.</p> |
| <h2 id="using-duplicate-detection-for-message-sending">Using Duplicate Detection for Message Sending</h2> |
| <p>Enabling duplicate message detection for sent messages is simple: you |
| just need to set a special property on the message to a unique value. |
| You can create the value however you like, as long as it is unique. When |
| the target server receives the message it will check if that property is |
| set, if it is, then it will check in its in memory cache if it has |
| already received a message with that value of the header. If it has |
| received a message with the same value before then it will ignore the |
| message.</p> |
| <blockquote> |
| <p><strong>Note</strong></p> |
| <p>Using duplicate detection to move messages between nodes can give you |
| the same <em>once and only once</em> delivery guarantees as if you were using |
| an XA transaction to consume messages from source and send them to the |
| target, but with less overhead and much easier configuration than |
| using XA.</p> |
| </blockquote> |
| <p>If you're sending messages in a transaction then you don't have to set |
| the property for <em>every</em> message you send in that transaction, you only |
| need to set it once in the transaction. If the server detects a |
| duplicate message for any message in the transaction, then it will |
| ignore the entire transaction.</p> |
| <p>The name of the property that you set is given by the value of |
| <code>org.apache.activemq.artemis.api.core.Message.HDR_DUPLICATE_DETECTION_ID</code>, which |
| is <code>_AMQ_DUPL_ID</code></p> |
| <p>The value of the property can be of type <code>byte[]</code> or <code>SimpleString</code> if |
| you're using the core API. If you're using JMS it must be a <code>String</code>, |
| and its value should be unique. An easy way of generating a unique id is |
| by generating a UUID.</p> |
| <p>Here's an example of setting the property using the core API:</p> |
| <pre><code class="lang-java">... |
| |
| ClientMessage message = session.createMessage(<span class="hljs-keyword">true</span>); |
| |
| SimpleString myUniqueID = <span class="hljs-string">"This is my unique id"</span>; <span class="hljs-comment">// Could use a UUID for this</span> |
| |
| message.setStringProperty(HDR_DUPLICATE_DETECTION_ID, myUniqueID); |
| </code></pre> |
| <p>And here's an example using the JMS API:</p> |
| <pre><code class="lang-java">... |
| |
| Message jmsMessage = session.createMessage(); |
| |
| String myUniqueID = <span class="hljs-string">"This is my unique id"</span>; <span class="hljs-comment">// Could use a UUID for this</span> |
| |
| message.setStringProperty(HDR_DUPLICATE_DETECTION_ID.toString(), myUniqueID); |
| |
| ... |
| </code></pre> |
| <h2 id="configuring-the-duplicate-id-cache">Configuring the Duplicate ID Cache</h2> |
| <p>The server maintains caches of received values of the |
| <code>org.apache.activemq.artemis.core.message.impl.HDR_DUPLICATE_DETECTION_ID</code> |
| property sent to each address. Each address has its own distinct cache.</p> |
| <p>The cache is a circular fixed size cache. If the cache has a maximum |
| size of <code>n</code> elements, then the <code>n + 1</code>th id stored will overwrite the |
| <code>0</code>th element in the cache.</p> |
| <p>The maximum size of the cache is configured by the parameter |
| <code>id-cache-size</code> in <code>broker.xml</code>, the default value is |
| <code>2000</code> elements.</p> |
| <p>The caches can also be configured to persist to disk or not. This is |
| configured by the parameter <code>persist-id-cache</code>, also in |
| <code>broker.xml</code>. If this is set to <code>true</code> then each id will |
| be persisted to permanent storage as they are received. The default |
| value for this parameter is <code>true</code>.</p> |
| <blockquote> |
| <p><strong>Note</strong></p> |
| <p>When choosing a size of the duplicate id cache be sure to set it to a |
| larger enough size so if you resend messages all the previously sent |
| ones are in the cache not having been overwritten.</p> |
| </blockquote> |
| <h2 id="duplicate-detection-and-bridges">Duplicate Detection and Bridges</h2> |
| <p>Core bridges can be configured to automatically add a unique duplicate |
| id value (if there isn't already one in the message) before forwarding |
| the message to it's target. This ensures that if the target server |
| crashes or the connection is interrupted and the bridge resends the |
| message, then if it has already been received by the target server, it |
| will be ignored.</p> |
| <p>To configure a core bridge to add the duplicate id header, simply set |
| the <code>use-duplicate-detection</code> to <code>true</code> when configuring a bridge in |
| <code>broker.xml</code>.</p> |
| <p>The default value for this parameter is <code>true</code>.</p> |
| <p>For more information on core bridges and how to configure them, please |
| see <a href="core-bridges.html">Core Bridges</a>.</p> |
| <h2 id="duplicate-detection-and-cluster-connections">Duplicate Detection and Cluster Connections</h2> |
| <p>Cluster connections internally use core bridges to move messages |
| reliable between nodes of the cluster. Consequently they can also be |
| configured to insert the duplicate id header for each message they move |
| using their internal bridges.</p> |
| <p>To configure a cluster connection to add the duplicate id header, simply |
| set the <code>use-duplicate-detection</code> to <code>true</code> when configuring a cluster |
| connection in <code>broker.xml</code>.</p> |
| <p>The default value for this parameter is <code>true</code>.</p> |
| <p>For more information on cluster connections and how to configure them, |
| please see <a href="clusters.html">Clusters</a>.</p> |
| |
| |
| </section> |
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