| <!DOCTYPE html> |
| <html lang="en"> |
| <head> |
| <meta charset="UTF-8"> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"> |
| <meta http-equiv="X-UA-Compatible" content="ie=edge"> |
| <title>ActiveMQ</title> |
| <link rel="icon" type="image/png" href="/assets/img/favicon.png"> |
| |
| <link rel="stylesheet" href="/css/main.css"> |
| <script defer src="https://use.fontawesome.com/releases/v5.0.8/js/all.js" integrity="sha384-SlE991lGASHoBfWbelyBPLsUlwY1GwNDJo3jSJO04KZ33K2bwfV9YBauFfnzvynJ" crossorigin="anonymous"></script> |
| <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script> |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script> |
| <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script> |
| </head> |
| |
| <body> |
| <nav class="navbar navbar-expand-lg navbar-light fixed-top"> |
| <div class="container"> |
| <!-- <a class="navbar-brand mr-auto" href="#"><img style="height: 50px" src="assets/img/apache-feather.png" /></a> --> |
| <a class="navbar-brand mr-auto" href="/"><img src="/assets/img/activemq_logo_black_small.png" style="height: 50px"/></a> |
| <button class="navbar-toggler ml-auto" type="button" data-toggle="collapse" data-target="#navbarContent" aria-controls="navbarContent" aria-expanded="false" aria-label="Toggle navigation"> |
| <span class="navbar-toggler-icon"></span> |
| </button> |
| |
| <div class="ml-auto collapse navbar-collapse" id="navbarContent"> |
| <ul class="navbar-nav ml-auto"> |
| <li class="nav-item"> |
| <a class="nav-link active" href="/index.html">Home</a> |
| </li> |
| <li class="nav-item dropdown"> |
| <a class="nav-link" id="navbarDropdownComponents" data-target="#" href="" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Components</a> |
| <ul class="dropdown-menu dropdown-menu-center" aria-labelledby="navbarDropdownComponents"> |
| <div class="row"> |
| <div class="col-12"> |
| <ul class="multi-column-dropdown"> |
| <li class="nav-item"><a class="dropdown-item" href="/components/classic">ActiveMQ 5</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/components/artemis/">ActiveMQ Artemis</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/components/nms">NMS Clients</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/components/cms">CMS Client</a></li> |
| </ul> |
| </div> |
| </div> |
| </ul> |
| </li> |
| <li class="nav-item dropdown"> |
| <a class="nav-link" id="navbarDropdownCommunity" data-target="#" href="" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Contact</a> |
| <ul class="dropdown-menu dropdown-menu-center multi-column columns-1" aria-labelledby="navbarDropdownCommunity"> |
| <div class="row"> |
| <div class="col-12"> |
| <ul class="multi-column-dropdown"> |
| <li class="nav-item"><a class="dropdown-item" href="/contact#mailing">Mailing Lists</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/contact#chat">Chat</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/contact#issues">Report Issues</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/contact#contributing">Contributing</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/security-advisories.html">Security</a></li> |
| </ul> |
| </div> |
| </div> |
| </ul> |
| </li> |
| <li class="nav-item dropdown"> |
| <a class="nav-link" id="navbarDropdownTeam" data-target="#" href="" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Apache</a> |
| <ul class="dropdown-menu dropdown-menu-center multi-column columns-1" aria-labelledby="navbarDropdownTeam"> |
| <div class="row"> |
| <div class="col-sm-12"> |
| <ul class="multi-column-dropdown"> |
| <li class="nav-item"><a class="dropdown-item" href="https://www.apache.org">The Apache Software Foundation</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="https://www.apache.org/licenses/">License</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="https://www.apache.org/foundation/sponsorship.html">Sponsorship</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="https://www.apache.org/foundation/thanks.html">Thanks</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/security-advisories.html">Security</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="https://www.apache.org/events/current-event">Events</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="https://people.apache.org/phonebook.html?pmc=activemq">PMC & Committers</a></li> |
| <li class="nav-item"><a class="dropdown-item" href="/team/reports">Board Reports</a></li> |
| </ul> |
| </div> |
| </div> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| </div> |
| </nav> |
| |
| <div class="content"> |
| <div class="page-title-activemq5"> |
| <div class="container"> |
| <h1>Total Ordering</h1> |
| </div> |
| </div> |
| <div class="container" > |
| <div class="row" style="margin-top: 30px"> |
| <div class="col-12 activemq5"> |
| <p><a href="features">Features</a> > <a href="message-dispatching-features">Message Dispatching Features</a> > <a href="total-ordering">Total Ordering</a></p> |
| |
| <p>Sometimes it can be useful to ensure that every topic consumer sees messages arriving on the topic in exactly the same order. Normally the broker will guarantee the order of all messages sent by the same producer. However, owing to the broker’s use of multiple threads and asynchronous processing, messages from different producers could arrive in different consumers in different orders.</p> |
| |
| <p>For example, if we have producers <strong><code class="highlighter-rouge">P</code></strong> and <strong><code class="highlighter-rouge">Q</code></strong> sending messages such that at about the same time <strong><code class="highlighter-rouge">P</code></strong> sends <strong><code class="highlighter-rouge">P1</code>, <code class="highlighter-rouge">P2</code></strong>, <strong><code class="highlighter-rouge">P3</code></strong> and <strong><code class="highlighter-rouge">Q</code></strong> sends <strong><code class="highlighter-rouge">Q1</code>, <code class="highlighter-rouge">Q2</code></strong>. Therefore, two different consumers <em>could</em> see messages arrive in the following order:</p> |
| |
| <p>consumer1: P1 P2 Q1 P3 Q2 |
| consumer2: P1 Q1 Q2 P2 P3</p> |
| |
| <p>In this example each producer’s messages are in self-relative order. However, the streams of messages across producers can get intermixed.</p> |
| |
| <p><em>Total Ordering</em> of a destination in ActiveMQ ensures that each consumer will see the same total order on that topic. This has a performance cost, since greater synchronization is required. This can be useful, particularly when very fast optimistic transactions are required. With total ordering the messages would arrive like this:</p> |
| |
| <p>consumer1: P1 P2 Q1 P3 Q2 |
| consumer2: P1 P2 Q1 P3 Q2</p> |
| |
| <h2 id="configuring-total-ordering">Configuring Total Ordering</h2> |
| |
| <p>Enable the <strong><code class="highlighter-rouge"><strictOrderDispatchPolicy/></code></strong> on the <a href="per-destination-policies">Per Destination Policies</a>. Here’s an example</p> |
| |
| <destinationPolicy> |
| <policyMap> |
| <policyEntries> |
| <policyEntry topic=">"> |
| <dispatchPolicy> |
| <strictOrderDispatchPolicy /> |
| </dispatchPolicy> |
| </policyEntry> |
| </policyEntries> |
| </policyMap> |
| </destinationPolicy> |
| |
| |
| </div> |
| </div> |
| </div> |
| </div> |
| <div class="row sitemap"> |
| <div class="col-sm-12"> |
| <div class="container"> |
| <div class="row"> |
| <div class="col-sm-12"> |
| <div class="row"> |
| <div class="col-sm-3"> |
| <div > |
| <img class="float-left" style="max-height: 100px" src="/assets/img/activemq_logo_white_vertical_small.png"/> |
| </div> |
| </div> |
| <div style="text-align: center; margin-bottom: 0px; margin-top: 30px; font-size: 65%" class="col-sm-6"> |
| <p>Apache ActiveMQ, ActiveMQ, ActiveMQ Artemis, Apache, the Apache feather logo, and the Apache ActiveMQ project logo are trademarks of The Apache Software Foundation. Copyright © 2019, The Apache Software Foundation. Licensed under <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License 2.0</a>.</p> |
| </div> |
| <div class="col-sm-3"> |
| <div > |
| <a href="https://www.apache.org"><img class="float-right" style="margin-top: 10px; max-height: 80px" src="/assets/img/apache-logo-small.png"/></a> |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| </div> |
| |
| </body> |
| </html> |
