| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <meta http-equiv="X-UA-Compatible" content="IE=edge"> |
| <meta name="viewport" content="width=device-width, initial-scale=1"> |
| |
| <link rel="shortcut icon" href="/favicon.ico" type="image/x-icon"> |
| <link rel="icon" href="/favicon.ico" type="image/x-icon"> |
| |
| <title>Trident Spouts</title> |
| |
| <!-- Bootstrap core CSS --> |
| <link href="/assets/css/bootstrap.min.css" rel="stylesheet"> |
| <!-- Bootstrap theme --> |
| <link href="/assets/css/bootstrap-theme.min.css" rel="stylesheet"> |
| |
| <!-- Custom styles for this template --> |
| <link rel="stylesheet" href="http://fortawesome.github.io/Font-Awesome/assets/font-awesome/css/font-awesome.css"> |
| <link href="/css/style.css" rel="stylesheet"> |
| <link href="/assets/css/owl.theme.css" rel="stylesheet"> |
| <link href="/assets/css/owl.carousel.css" rel="stylesheet"> |
| <script type="text/javascript" src="/assets/js/jquery.min.js"></script> |
| <script type="text/javascript" src="/assets/js/bootstrap.min.js"></script> |
| <script type="text/javascript" src="/assets/js/owl.carousel.min.js"></script> |
| <script type="text/javascript" src="/assets/js/storm.js"></script> |
| <!-- Just for debugging purposes. Don't actually copy these 2 lines! --> |
| <!--[if lt IE 9]><script src="../../assets/js/ie8-responsive-file-warning.js"></script><![endif]--> |
| |
| <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries --> |
| <!--[if lt IE 9]> |
| <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script> |
| <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script> |
| <![endif]--> |
| </head> |
| |
| |
| <body> |
| <header> |
| <div class="container-fluid"> |
| <div class="row"> |
| <div class="col-md-5"> |
| <a href="/index.html"><img src="/images/logo.png" class="logo" /></a> |
| </div> |
| <div class="col-md-5"> |
| |
| <h1>Version: 1.2.3</h1> |
| |
| </div> |
| <div class="col-md-2"> |
| <a href="/downloads.html" class="btn-std btn-block btn-download">Download</a> |
| </div> |
| </div> |
| </div> |
| </header> |
| <!--Header End--> |
| <!--Navigation Begin--> |
| <div class="navbar" role="banner"> |
| <div class="container-fluid"> |
| <div class="navbar-header"> |
| <button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".bs-navbar-collapse"> |
| <span class="icon-bar"></span> |
| <span class="icon-bar"></span> |
| <span class="icon-bar"></span> |
| </button> |
| </div> |
| <nav class="collapse navbar-collapse bs-navbar-collapse" role="navigation"> |
| <ul class="nav navbar-nav"> |
| <li><a href="/index.html" id="home">Home</a></li> |
| <li><a href="/getting-help.html" id="getting-help">Getting Help</a></li> |
| <li><a href="/about/integrates.html" id="project-info">Project Information</a></li> |
| <li class="dropdown"> |
| <a href="#" class="dropdown-toggle" data-toggle="dropdown" id="documentation">Documentation <b class="caret"></b></a> |
| <ul class="dropdown-menu"> |
| |
| |
| <li><a href="/releases/2.3.0/index.html">2.3.0</a></li> |
| |
| |
| |
| <li><a href="/releases/2.2.0/index.html">2.2.0</a></li> |
| |
| |
| |
| <li><a href="/releases/2.1.0/index.html">2.1.0</a></li> |
| |
| |
| |
| <li><a href="/releases/2.0.0/index.html">2.0.0</a></li> |
| |
| |
| |
| <li><a href="/releases/1.2.3/index.html">1.2.3</a></li> |
| |
| |
| </ul> |
| </li> |
| <li><a href="/talksAndVideos.html">Talks and Slideshows</a></li> |
| <li class="dropdown"> |
| <a href="#" class="dropdown-toggle" data-toggle="dropdown" id="contribute">Community <b class="caret"></b></a> |
| <ul class="dropdown-menu"> |
| <li><a href="/contribute/Contributing-to-Storm.html">Contributing</a></li> |
| <li><a href="/contribute/People.html">People</a></li> |
| <li><a href="/contribute/BYLAWS.html">ByLaws</a></li> |
| </ul> |
| </li> |
| <li><a href="/2021/09/27/storm230-released.html" id="news">News</a></li> |
| </ul> |
| </nav> |
| </div> |
| </div> |
| |
| |
| |
| <div class="container-fluid"> |
| <h1 class="page-title">Trident Spouts</h1> |
| <div class="row"> |
| <div class="col-md-12"> |
| <!-- Documentation --> |
| |
| <p class="post-meta"></p> |
| |
| <div class="documentation-content"><h1 id="trident-spouts">Trident spouts</h1> |
| |
| <p>Like in the vanilla Storm API, spouts are the source of streams in a Trident topology. On top of the vanilla Storm spouts, Trident exposes additional APIs for more sophisticated spouts.</p> |
| |
| <p>There is an inextricable link between how you source your data streams and how you update state (e.g. databases) based on those data streams. See <a href="Trident-state.html">Trident state doc</a> for an explanation of this – understanding this link is imperative for understanding the spout options available.</p> |
| |
| <p>Regular Storm spouts will be non-transactional spouts in a Trident topology. To use a regular Storm IRichSpout, create the stream like this in a TridentTopology:</p> |
| <div class="highlight"><pre><code class="language-java" data-lang="java"><span class="n">TridentTopology</span> <span class="n">topology</span> <span class="o">=</span> <span class="k">new</span> <span class="n">TridentTopology</span><span class="o">();</span> |
| <span class="n">topology</span><span class="o">.</span><span class="na">newStream</span><span class="o">(</span><span class="s">"myspoutid"</span><span class="o">,</span> <span class="k">new</span> <span class="n">MyRichSpout</span><span class="o">());</span> |
| </code></pre></div> |
| <p>All spouts in a Trident topology are required to be given a unique identifier for the stream – this identifier must be unique across all topologies run on the cluster. Trident will use this identifier to store metadata about what the spout has consumed in Zookeeper, including the txid and any metadata associated with the spout.</p> |
| |
| <p>You can configure the Zookeeper storage of spout metadata via the following configuration options:</p> |
| |
| <ol> |
| <li><code>transactional.zookeeper.servers</code>: A list of Zookeeper hostnames </li> |
| <li><code>transactional.zookeeper.port</code>: The port of the Zookeeper cluster</li> |
| <li><code>transactional.zookeeper.root</code>: The root dir in Zookeeper where metadata is stored. Metadata will be stored at the path <root path>/<spout id></li> |
| </ol> |
| |
| <h2 id="pipelining">Pipelining</h2> |
| |
| <p>By default, Trident processes a single batch at a time, waiting for the batch to succeed or fail before trying another batch. You can get significantly higher throughput – and lower latency of processing of each batch – by pipelining the batches. You configure the maximum amount of batches to be processed simultaneously with the "topology.max.spout.pending" property. </p> |
| |
| <p>Even while processing multiple batches simultaneously, Trident will order any state updates taking place in the topology among batches. For example, suppose you're doing a global count aggregation into a database. The idea is that while you're updating the count in the database for batch 1, you can still be computing the partial counts for batches 2 through 10. Trident won't move on to the state updates for batch 2 until the state updates for batch 1 have succeeded. This is essential for achieving exactly-once processing semantics, as outline in <a href="Trident-state.html">Trident state doc</a>.</p> |
| |
| <h2 id="trident-spout-types">Trident spout types</h2> |
| |
| <p>Here are the following spout APIs available:</p> |
| |
| <ol> |
| <li><a href="http://github.com/apache/storm/blob/v1.2.3/storm-core/src/jvm/org/apache/storm/trident/spout/ITridentSpout.java">ITridentSpout</a>: The most general API that can support transactional or opaque transactional semantics. Generally you'll use one of the partitioned flavors of this API rather than this one directly.</li> |
| <li><a href="http://github.com/apache/storm/blob/v1.2.3/storm-core/src/jvm/org/apache/storm/trident/spout/IBatchSpout.java">IBatchSpout</a>: A non-transactional spout that emits batches of tuples at a time</li> |
| <li><a href="http://github.com/apache/storm/blob/v1.2.3/storm-core/src/jvm/org/apache/storm/trident/spout/IPartitionedTridentSpout.java">IPartitionedTridentSpout</a>: A transactional spout that reads from a partitioned data source (like a cluster of Kafka servers)</li> |
| <li><a href="http://github.com/apache/storm/blob/v1.2.3/storm-core/src/jvm/org/apache/storm/trident/spout/IOpaquePartitionedTridentSpout.java">IOpaquePartitionedTridentSpout</a>: An opaque transactional spout that reads from a partitioned data source</li> |
| </ol> |
| |
| <p>And, like mentioned in the beginning of this tutorial, you can use regular IRichSpout's as well.</p> |
| </div> |
| |
| |
| </div> |
| </div> |
| </div> |
| <footer> |
| <div class="container-fluid"> |
| <div class="row"> |
| <div class="col-md-3"> |
| <div class="footer-widget"> |
| <h5>Meetups</h5> |
| <ul class="latest-news"> |
| |
| <li><a href="http://www.meetup.com/Apache-Storm-Apache-Kafka/">Apache Storm & Apache Kafka</a> <span class="small">(Sunnyvale, CA)</span></li> |
| |
| <li><a href="http://www.meetup.com/Apache-Storm-Kafka-Users/">Apache Storm & Kafka Users</a> <span class="small">(Seattle, WA)</span></li> |
| |
| <li><a href="http://www.meetup.com/New-York-City-Storm-User-Group/">NYC Storm User Group</a> <span class="small">(New York, NY)</span></li> |
| |
| <li><a href="http://www.meetup.com/Bay-Area-Stream-Processing">Bay Area Stream Processing</a> <span class="small">(Emeryville, CA)</span></li> |
| |
| <li><a href="http://www.meetup.com/Boston-Storm-Users/">Boston Realtime Data</a> <span class="small">(Boston, MA)</span></li> |
| |
| <li><a href="http://www.meetup.com/storm-london">London Storm User Group</a> <span class="small">(London, UK)</span></li> |
| |
| <!-- <li><a href="http://www.meetup.com/Apache-Storm-Kafka-Users/">Seatle, WA</a> <span class="small">(27 Jun 2015)</span></li> --> |
| </ul> |
| </div> |
| </div> |
| <div class="col-md-3"> |
| <div class="footer-widget"> |
| <h5>About Apache Storm</h5> |
| <p>Apache Storm integrates with any queueing system and any database system. Apache Storm's spout abstraction makes it easy to integrate a new queuing system. Likewise, integrating Apache Storm with database systems is easy.</p> |
| </div> |
| </div> |
| <div class="col-md-3"> |
| <div class="footer-widget"> |
| <h5>First Look</h5> |
| <ul class="footer-list"> |
| <li><a href="/releases/current/Rationale.html">Rationale</a></li> |
| <li><a href="/releases/current/Tutorial.html">Tutorial</a></li> |
| <li><a href="/releases/current/Setting-up-development-environment.html">Setting up development environment</a></li> |
| <li><a href="/releases/current/Creating-a-new-Storm-project.html">Creating a new Apache Storm project</a></li> |
| </ul> |
| </div> |
| </div> |
| <div class="col-md-3"> |
| <div class="footer-widget"> |
| <h5>Documentation</h5> |
| <ul class="footer-list"> |
| <li><a href="/releases/current/index.html">Index</a></li> |
| <li><a href="/releases/current/javadocs/index.html">Javadoc</a></li> |
| <li><a href="/releases/current/FAQ.html">FAQ</a></li> |
| </ul> |
| </div> |
| </div> |
| </div> |
| <hr/> |
| <div class="row"> |
| <div class="col-md-12"> |
| <p align="center">Copyright © 2019 <a href="http://www.apache.org">Apache Software Foundation</a>. All Rights Reserved. |
| <br>Apache Storm, Apache, the Apache feather logo, and the Apache Storm project logos are trademarks of The Apache Software Foundation. |
| <br>All other marks mentioned may be trademarks or registered trademarks of their respective owners.</p> |
| </div> |
| </div> |
| </div> |
| </footer> |
| <!--Footer End--> |
| <!-- Scroll to top --> |
| <span class="totop"><a href="#"><i class="fa fa-angle-up"></i></a></span> |
| |
| </body> |
| |
| </html> |
| |
