<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><title>Non-persistent messaging · Apache Pulsar</title><meta name="viewport" content="width=device-width, initial-scale=1.0"/><meta name="generator" content="Docusaurus"/><meta name="description" content="**Non-persistent topics** are Pulsar topics in which message data is *never* [persistently stored](/docs/en/2.9.0/concepts-architecture-overview#persistent-storage) and kept only in memory. This cookbook provides:"/><meta name="docsearch:version" content="2.9.0"/><meta name="docsearch:language" content="en"/><meta property="og:title" content="Non-persistent messaging · Apache Pulsar"/><meta property="og:type" content="website"/><meta property="og:url" content="https://pulsar.apache.org/"/><meta property="og:description" content="**Non-persistent topics** are Pulsar topics in which message data is *never* [persistently stored](/docs/en/2.9.0/concepts-architecture-overview#persistent-storage) and kept only in memory. This cookbook provides:"/><meta name="twitter:card" content="summary"/><meta name="twitter:image" content="https://pulsar.apache.org/img/pulsar.svg"/><link rel="shortcut icon" href="/img/pulsar.ico"/><link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/atom-one-dark.min.css"/><link rel="alternate" type="application/atom+xml" href="https://pulsar.apache.org/blog/atom.xml" title="Apache Pulsar Blog ATOM Feed"/><link rel="alternate" type="application/rss+xml" href="https://pulsar.apache.org/blog/feed.xml" title="Apache Pulsar Blog RSS Feed"/><link rel="stylesheet" href="/css/code-blocks-buttons.css"/><script type="text/javascript" src="https://buttons.github.io/buttons.js"></script><script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.0/clipboard.min.js"></script><script type="text/javascript" src="/js/custom.js"></script><script src="/js/scrollSpy.js"></script><link rel="stylesheet" href="/css/main.css"/><script src="/js/codetabs.js"></script></head><body class="sideNavVisible separateOnPageNav"><div class="fixedHeaderContainer"><div class="headerWrapper wrapper"><header><a href="/en"><img class="logo" src="/img/pulsar.svg" alt="Apache Pulsar"/></a><a href="/en/versions"><h3>2.9.0</h3></a><div class="navigationWrapper navigationSlider"><nav class="slidingNav"><ul class="nav-site nav-site-internal"><li class="siteNavGroupActive"><a href="/docs/en/2.9.0/getting-started-standalone" target="_self">Docs</a></li><li class=""><a href="/en/download" target="_self">Download</a></li><li class="siteNavGroupActive"><a href="/docs/en/2.9.0/client-libraries" target="_self">Clients</a></li><li class=""><a href="#restapis" target="_self">REST APIs</a></li><li class=""><a href="#cli" target="_self">Cli</a></li><li class=""><a href="/blog/" target="_self">Blog</a></li><li class=""><a href="#community" target="_self">Community</a></li><li class=""><a href="#apache" target="_self">Apache</a></li><li class=""><a href="https://pulsar-next.staged.apache.org/" target="_self">New Website (Beta)</a></li><span><li><a id="languages-menu" href="#"><img class="languages-icon" src="/img/language.svg" alt="Languages icon"/>English</a><div id="languages-dropdown" class="hide"><ul id="languages-dropdown-items"><li><a href="/docs/ja/2.9.0/cookbooks-non-persistent">日本語</a></li><li><a href="/docs/fr/2.9.0/cookbooks-non-persistent">Français</a></li><li><a href="/docs/ko/2.9.0/cookbooks-non-persistent">한국어</a></li><li><a href="/docs/zh-CN/2.9.0/cookbooks-non-persistent">中文</a></li><li><a href="/docs/zh-TW/2.9.0/cookbooks-non-persistent">繁體中文</a></li><li><a href="https://crowdin.com/project/apache-pulsar" target="_blank" rel="noreferrer noopener">Help Translate</a></li></ul></div></li><script>
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Kubernetes</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Concepts and Architecture</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-overview">Overview</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-messaging">Messaging</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-architecture-overview">Architecture</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-clients">Clients</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-replication">Geo Replication</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-multi-tenancy">Multi Tenancy</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-authentication">Authentication and Authorization</a></li><li class="navListItem"><a class="navItem" href="/docs/en/2.9.0/concepts-topic-compaction">Topic 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<ul>
<li>A basic <a href="#overview">conceptual overview</a> of non-persistent topics</li>
<li>Information about <a href="#configuration">configurable parameters</a> related to non-persistent topics</li>
<li>A guide to the <a href="#cli">CLI interface</a> for managing non-persistent topics</li>
</ul>
<h2><a class="anchor" aria-hidden="true" id="overview"></a><a href="#overview" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Overview</h2>
<p>By default, Pulsar persistently stores <em>all</em> unacknowledged messages on multiple <a href="#persistent-storage">BookKeeper</a> bookies (storage nodes). Data for messages on persistent topics can thus survive broker restarts and subscriber failover.</p>
<p>Pulsar also, however, supports <strong>non-persistent topics</strong>, which are topics on which messages are <em>never</em> persisted to disk and live only in memory. When using non-persistent delivery, killing a Pulsar <a href="/docs/en/2.9.0/reference-terminology#broker">broker</a> or disconnecting a subscriber to a topic means that all in-transit messages are lost on that (non-persistent) topic, meaning that clients may see message loss.</p>
<p>Non-persistent topics have names of this form (note the <code>non-persistent</code> in the name):</p>
<pre><code class="hljs css language-http">non-persistent://tenant/namespace/topic
</code></pre>
<blockquote>
<p>For more high-level information about non-persistent topics, see the <a href="/docs/en/2.9.0/concepts-messaging#non-persistent-topics">Concepts and Architecture</a> documentation.</p>
</blockquote>
<h2><a class="anchor" aria-hidden="true" id="using"></a><a href="#using" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Using</h2>
<blockquote>
<p>In order to use non-persistent topics, they must be <a href="#enabling">enabled</a> in your Pulsar broker configuration.</p>
</blockquote>
<p>In order to use non-persistent topics, you only need to differentiate them by name when interacting with them. This <a href="/docs/en/2.9.0/reference-cli-tools#pulsar-client-produce"><code>pulsar-client produce</code></a> command, for example, would produce one message on a non-persistent topic in a standalone cluster:</p>
<pre><code class="hljs css language-bash">$ bin/pulsar-client produce non-persistent://public/default/example-np-topic \
  --num-produce 1 \
  --messages <span class="hljs-string">"This message will be stored only in memory"</span>
</code></pre>
<blockquote>
<p>For a more thorough guide to non-persistent topics from an administrative perspective, see the <a href="/docs/en/2.9.0/admin-api-topics">Non-persistent topics</a> guide.</p>
</blockquote>
<h2><a class="anchor" aria-hidden="true" id="enabling"></a><a href="#enabling" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Enabling</h2>
<p>In order to enable non-persistent topics in a Pulsar broker, the <a href="/docs/en/2.9.0/reference-configuration#broker-enableNonPersistentTopics"><code>enableNonPersistentTopics</code></a> must be set to <code>true</code>. This is the default, and so you won't need to take any action to enable non-persistent messaging.</p>
<blockquote>
<h4><a class="anchor" aria-hidden="true" id="configuration-for-standalone-mode"></a><a href="#configuration-for-standalone-mode" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Configuration for standalone mode</h4>
<p>If you're running Pulsar in standalone mode, the same configurable parameters are available but in the <a href="/docs/en/2.9.0/reference-configuration#standalone"><code>standalone.conf</code></a> configuration file.</p>
</blockquote>
<p>If you'd like to enable <em>only</em> non-persistent topics in a broker, you can set the <a href="/docs/en/2.9.0/reference-configuration#broker-enablePersistentTopics"><code>enablePersistentTopics</code></a> parameter to <code>false</code> and the <code>enableNonPersistentTopics</code> parameter to <code>true</code>.</p>
<h2><a class="anchor" aria-hidden="true" id="managing-with-cli"></a><a href="#managing-with-cli" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Managing with cli</h2>
<p>Non-persistent topics can be managed using the <a href="/docs/en/2.9.0/reference-pulsar-admin#non-persistent"><code>pulsar-admin non-persistent</code></a> command-line interface. With that interface you can perform actions like <a href="/docs/en/2.9.0/reference-pulsar-admin#non-persistent-create-partitioned-topic">create a partitioned non-persistent topic</a>, get <a href="/docs/en/2.9.0/reference-pulsar-admin#non-persistent-stats">stats</a> for a non-persistent topic, <a href="/docs/en/2.9.0/reference-pulsar-admin">list</a> non-persistent topics under a namespace, and more.</p>
<h2><a class="anchor" aria-hidden="true" id="using-with-pulsar-clients"></a><a href="#using-with-pulsar-clients" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Using with Pulsar clients</h2>
<p>You shouldn't need to make any changes to your Pulsar clients to use non-persistent messaging beyond making sure that you use proper <a href="#using">topic names</a> with <code>non-persistent</code> as the topic type.</p>
</span></div></article></div><div class="docs-prevnext"><a class="docs-prev button" href="/docs/en/2.9.0/cookbooks-deduplication"><span class="arrow-prev">← </span><span>Message deduplication</span></a><a class="docs-next button" href="/docs/en/2.9.0/cookbooks-retention-expiry"><span>Message retention and expiry</span><span class="arrow-next"> →</span></a></div></div></div><nav class="onPageNav"><ul class="toc-headings"><li><a href="#overview">Overview</a></li><li><a href="#using">Using</a></li><li><a href="#enabling">Enabling</a></li><li><a href="#managing-with-cli">Managing with cli</a></li><li><a href="#using-with-pulsar-clients">Using with Pulsar clients</a></li></ul></nav></div><footer class="nav-footer" id="footer"><section class="copyright">Copyright © 2022 The Apache Software Foundation. All Rights Reserved. Apache, Apache Pulsar and the Apache feather logo are trademarks of The Apache Software Foundation.</section><span><script>
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