| <div role="region" aria-label="Skip to main content"><a class="skipToContent_fXgn" href="#__docusaurus_skipToContent_fallback">Skip to main content</a></div><nav aria-label="Main" class="navbar navbar--fixed-top"><div class="navbar__inner"><div class="navbar__items"><button aria-label="Toggle navigation bar" aria-expanded="false" class="navbar__toggle clean-btn" type="button"><svg width="30" height="30" viewBox="0 0 30 30" aria-hidden="true"><path stroke="currentColor" stroke-linecap="round" stroke-miterlimit="10" stroke-width="2" d="M4 7h22M4 15h22M4 23h22"></path></svg></button><a class="navbar__brand" href="/"><div class="navbar__logo"><img src="/img/Apache_RocketMQ_logo.svg.png" alt="My Site Logo" class="themedImage_ToTc themedImage--light_HNdA"><img src="/img/Apache_RocketMQ_logo.svg.png" alt="My Site Logo" class="themedImage_ToTc themedImage--dark_i4oU"></div><b class="navbar__title text--truncate">Apache RocketMQ</b></a></div><div class="navbar__items navbar__items--right"><a href="https://github.com/apache/rocketmq" target="_blank" rel="noopener noreferrer" class="navbar__item navbar__link">GitHub<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link"><svg viewBox="0 0 24 24" width="20" height="20" aria-hidden="true" class="iconLanguage_nlXk"><path fill="currentColor" d="M12.87 15.07l-2.54-2.51.03-.03c1.74-1.94 2.98-4.17 3.71-6.53H17V4h-7V2H8v2H1v1.99h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04zM18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12zm-2.62 7l1.62-4.33L19.12 17h-3.24z"></path></svg>English</a><ul class="dropdown__menu"><li><a href="/zh/docs/introduction/02concepts" target="_self" rel="noopener noreferrer" class="dropdown__link" lang="zh">简体中文</a></li><li><a href="/docs/introduction/02concepts" target="_self" rel="noopener noreferrer" class="dropdown__link dropdown__link--active" lang="en">English</a></li></ul></div><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link">Docs</a><ul class="dropdown__menu"><li><a aria-current="page" class="dropdown__link dropdown__link--active" href="/docs/">5.0</a></li><li><a class="dropdown__link" href="/docs/4.x/">4.x</a></li></ul></div><a class="navbar__item navbar__link" href="/download">Download</a><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link">Blog</a><ul class="dropdown__menu"><li><a class="dropdown__link" href="/blog">User Cases</a></li><li><a class="dropdown__link" href="/events">Activity</a></li><li><a class="dropdown__link" href="/release-notes">Change Log</a></li><li><a class="dropdown__link" href="/news">RocketMQ News</a></li></ul></div><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link">Community</a><ul class="dropdown__menu"><li><a class="dropdown__link" href="/contact">Join Community</a></li><li><a class="dropdown__link" href="/origin">Origin</a></li><li><a class="dropdown__link" href="/team">Teams</a></li><li><a class="dropdown__link" href="/docs/contributionGuide/01how-to-contribute">Contributions</a></li><li><a class="dropdown__link" href="/enterprise">Enterprises</a></li></ul></div><div class="toggle_vylO colorModeToggle_DEke"><button class="clean-btn toggleButton_gllP toggleButtonDisabled_aARS" type="button" disabled="" title="Switch between dark and light mode (currently light mode)" aria-label="Switch between dark and light mode (currently light mode)" aria-live="polite"><svg viewBox="0 0 24 24" width="24" height="24" class="lightToggleIcon_pyhR"><path fill="currentColor" d="M12,9c1.65,0,3,1.35,3,3s-1.35,3-3,3s-3-1.35-3-3S10.35,9,12,9 M12,7c-2.76,0-5,2.24-5,5s2.24,5,5,5s5-2.24,5-5 S14.76,7,12,7L12,7z M2,13l2,0c0.55,0,1-0.45,1-1s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S1.45,13,2,13z M20,13l2,0c0.55,0,1-0.45,1-1 s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S19.45,13,20,13z M11,2v2c0,0.55,0.45,1,1,1s1-0.45,1-1V2c0-0.55-0.45-1-1-1S11,1.45,11,2z M11,20v2c0,0.55,0.45,1,1,1s1-0.45,1-1v-2c0-0.55-0.45-1-1-1C11.45,19,11,19.45,11,20z M5.99,4.58c-0.39-0.39-1.03-0.39-1.41,0 c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0s0.39-1.03,0-1.41L5.99,4.58z M18.36,16.95 c-0.39-0.39-1.03-0.39-1.41,0c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0c0.39-0.39,0.39-1.03,0-1.41 L18.36,16.95z M19.42,5.99c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06c-0.39,0.39-0.39,1.03,0,1.41 s1.03,0.39,1.41,0L19.42,5.99z M7.05,18.36c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06 c-0.39,0.39-0.39,1.03,0,1.41s1.03,0.39,1.41,0L7.05,18.36z"></path></svg><svg viewBox="0 0 24 24" width="24" height="24" class="darkToggleIcon_wfgR"><path fill="currentColor" d="M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27C17.45,17.19,14.93,19,12,19 c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z M12,3c-4.97,0-9,4.03-9,9s4.03,9,9,9s9-4.03,9-9c0-0.46-0.04-0.92-0.1-1.36 c-0.98,1.37-2.58,2.26-4.4,2.26c-2.98,0-5.4-2.42-5.4-5.4c0-1.81,0.89-3.42,2.26-4.4C12.92,3.04,12.46,3,12,3L12,3z"></path></svg></button></div><div class="searchBox_ZlJk"><button type="button" class="DocSearch DocSearch-Button" aria-label="Search"><span class="DocSearch-Button-Container"><svg width="20" height="20" class="DocSearch-Search-Icon" viewBox="0 0 20 20" aria-hidden="true"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">Search</span></span><span class="DocSearch-Button-Keys"></span></button></div></div></div><div role="presentation" class="navbar-sidebar__backdrop"></div></nav><div id="__docusaurus_skipToContent_fallback" class="main-wrapper mainWrapper_z2l0 docsWrapper_BCFX"><button aria-label="Scroll back to top" class="clean-btn theme-back-to-top-button backToTopButton_sjWU" type="button"></button><div class="docPage__5DB"><aside class="theme-doc-sidebar-container docSidebarContainer_b6E3"><div class="sidebarViewport_Xe31"><div class="sidebar_njMd"><nav aria-label="Docs sidebar" class="menu thin-scrollbar menu_SIkG"><ul class="theme-doc-sidebar-menu menu__list"><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret menu__link--active" aria-expanded="true" href="/docs/">Introduction</a></div><ul style="display:block;overflow:visible;height:auto" class="menu__list"><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/docs/">Why choose RocketMQ</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link menu__link--active" aria-current="page" tabindex="0" href="/docs/introduction/02concepts">Concepts</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/docs/introduction/03limits">Parameter Constraints and Suggestions</a></li></ul></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/quickStart/01quickstart">Quick Start</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/domainModel/01main">Domain Model</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/featureBehavior/01normalmessage">Feature Behavior</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/deploymentOperations/01deploy">Deployment & Operations</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/observability/01metrics">Observability</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/sdk/01overview">Client SDK</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/bestPractice/01bestpractice">Best Practice</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/eventbridge/01RocketMQEventBridgeConcepts">RocketMQ EventBridge</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/mqtt/01RocketMQMQTTOverview">RocketMQ MQTT</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/connect/01RocketMQ Connect Overview">RocketMQ Connect</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/streams/01RocketMQ Streams Overview">RocketMQ Streams</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/docs/contributionGuide/01how-to-contribute">Contribution Guide</a></div></li></ul></nav></div></div></aside><main class="docMainContainer_gTbr"><div class="container padding-top--md padding-bottom--lg"><div class="row"><div class="col docItemCol_VOVn"><div class="docItemContainer_Djhp"><article><nav class="theme-doc-breadcrumbs breadcrumbsContainer_Z_bl" aria-label="Breadcrumbs"><ul class="breadcrumbs" itemscope="" itemtype="https://schema.org/BreadcrumbList"><li class="breadcrumbs__item"><a aria-label="Home page" class="breadcrumbs__link" href="/"><svg viewBox="0 0 24 24" class="breadcrumbHomeIcon_YNFT"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Introduction</span><meta itemprop="position" content="1"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">Concepts</span><meta itemprop="position" content="2"></li></ul></nav><span class="theme-doc-version-badge badge badge--secondary">Version: 5.0</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><h1>Concepts</h1><p>This section describes the core concepts of Apache RocketMQ.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="topic">Topic<a href="#topic" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A topic is a top-level container that is used in Apache RocketMQ to transfer and store messages that belong to the same business logic.Learn more <a href="/docs/domainModel/02topic">Topic</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messagetype">MessageType<a href="#messagetype" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>Categories defined by message transfer characteristics for type management and security verification. Apache RocketMQ support NORMAL,FIFO,TRANSACTION and DELAY message type.</p><div class="theme-admonition theme-admonition-info alert alert--info admonition_LlT9"><div class="admonitionHeading_tbUL"><span class="admonitionIcon_kALy"><svg viewBox="0 0 14 16"><path fill-rule="evenodd" d="M7 2.3c3.14 0 5.7 2.56 5.7 5.7s-2.56 5.7-5.7 5.7A5.71 5.71 0 0 1 1.3 8c0-3.14 2.56-5.7 5.7-5.7zM7 1C3.14 1 0 4.14 0 8s3.14 7 7 7 7-3.14 7-7-3.14-7-7-7zm1 3H6v5h2V4zm0 6H6v2h2v-2z"></path></svg></span>info</div><div class="admonitionContent_S0QG"><p>Starting from version 5.0, Apache RocketMQ supports enforcing the validation of message types, that is, each topic only allows messages of a single type to be sent. This can better facilitate operation and management of production systems and avoid confusion. However, to ensure backward compatibility with version 4.x, the validation feature is enable by default.</p></div></div><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messagequeue">MessageQueue<a href="#messagequeue" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>MessageQueue is a container that is used to store and transmit messages in Apache RocketMQ. MessageQueue is the smallest unit of storage for Apache RocketMQ messages. Learn more <a href="/docs/domainModel/03messagequeue">MessageQueue</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="message">Message<a href="#message" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A message is the smallest unit of data transmission in Apache RocketMQ. A producer encapsulates the load and extended attributes of business data into messages and sends the messages to a Apache RocketMQ broker. Then, the broker delivers the messages to the consumer based on the relevant semantics. Learn more<a href="/docs/domainModel/04message">Message</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messageview">MessageView<a href="#messageview" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>MessageView is read-only interface to message from a development perspective. The message view allows you to read multiple properties and payload information inside a message, but you cannot make any changes to the message itself.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messagetag">MessageTag<a href="#messagetag" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>MessageTag is a fine-grained message classification property that allows message to be subdivided below the topic level. Consumers implement message filtering by subscribing to specific tags. Learn more <a href="/docs/featureBehavior/07messagefilter">MessageFilter</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messageoffset">MessageOffset<a href="#messageoffset" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>Messages are stored in the queue in order of precedence, each message has a unique coordinate of type Long in the queue, which is defined as the message site. Learn more <a href="/docs/featureBehavior/09consumerprogress">Consumer progress management</a>。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="consumeroffset">ConsumerOffset<a href="#consumeroffset" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A message is not removed from the queue immediately after it has been consumed by a consumer, Apache RocketMQ will record the last consumed message based on each consumer group. Learn more <a href="/docs/featureBehavior/09consumerprogress">Consumer progress management</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="messagekey">MessageKey<a href="#messagekey" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>MessageKey is The message-oriented index property. By setting the message index, you can quickly find the corresponding message content.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="producer">Producer<a href="#producer" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A producer in Apache RocketMQ is a functional messaging entity that creates messages and sends them to the server. A producer is typically integrated on the business system and serves to encapsulate data as messages in Apache RocketMQ and send the messages to the server. Learn more <a href="/docs/domainModel/04producer">Producer</a>。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="transactionchecker">TransactionChecker<a href="#transactionchecker" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>Apache RocketMQ uses a transaction messaging mechanism that requires a producer to implement a transaction checker to ensure eventual consistency of transactions. Learn more<a href="/docs/featureBehavior/04transactionmessage">Transaction Message</a>。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="consumergroup">ConsumerGroup<a href="#consumergroup" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A consumer group is a load balancing group that contains consumers that use the same consumption behaviors in Apache RocketMQ. Learn more <a href="/docs/domainModel/07consumergroup">ConsumerGroup</a>。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="consumer">Consumer<a href="#consumer" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A consumer is an entity that receives and processes messages in Apache RocketMQ. Consumers are usually integrated in business systems. They obtain messages from Apache RocketMQ brokers and convert the messages into information that can be perceived and processed by business logic. Learn more <a href="/docs/domainModel/08consumer">Consumer</a>。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="subscription">Subscription<a href="#subscription" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>A subscription is the rule and status settings for consumers to obtain and process messages in Apache RocketMQ. Subscriptions are dynamically registered by consumer groups with brokers. Messages are then matched and consumed based on the filter rules defined by subscriptions. Learn more <a href="/docs/domainModel/09subscription">Subscription</a>。</p></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class="col"><a href="https://github.com/apache/rocketmq-site/tree/new-official-website/versioned_docs/version-5.0/01-introduction/02concepts.md" target="_blank" rel="noreferrer noopener" class="theme-edit-this-page"><svg fill="currentColor" height="20" width="20" viewBox="0 0 40 40" class="iconEdit_Z9Sw" aria-hidden="true"><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"></path></g></svg>Edit this page</a></div><div class="col lastUpdated_vwxv"></div></div></footer></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages navigation"><a class="pagination-nav__link pagination-nav__link--prev" href="/docs/"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">Why choose RocketMQ</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/docs/introduction/03limits"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">Parameter Constraints and Suggestions</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#topic" class="table-of-contents__link toc-highlight">Topic</a></li><li><a href="#messagetype" class="table-of-contents__link toc-highlight">MessageType</a></li><li><a href="#messagequeue" class="table-of-contents__link toc-highlight">MessageQueue</a></li><li><a href="#message" class="table-of-contents__link toc-highlight">Message</a></li><li><a href="#messageview" class="table-of-contents__link toc-highlight">MessageView</a></li><li><a href="#messagetag" class="table-of-contents__link toc-highlight">MessageTag</a></li><li><a href="#messageoffset" class="table-of-contents__link toc-highlight">MessageOffset</a></li><li><a href="#consumeroffset" class="table-of-contents__link toc-highlight">ConsumerOffset</a></li><li><a href="#messagekey" class="table-of-contents__link toc-highlight">MessageKey</a></li><li><a href="#producer" class="table-of-contents__link toc-highlight">Producer</a></li><li><a href="#transactionchecker" class="table-of-contents__link toc-highlight">TransactionChecker</a></li><li><a href="#consumergroup" class="table-of-contents__link toc-highlight">ConsumerGroup</a></li><li><a href="#consumer" class="table-of-contents__link toc-highlight">Consumer</a></li><li><a href="#subscription" class="table-of-contents__link toc-highlight">Subscription</a></li></ul></div></div></div></div></main></div></div><footer class="footer footer--dark"><div class="container container-fluid"><div class="row footer__links"><div class="col footer__col"><div class="footer__title">Learn</div><ul class="footer__items clean-list"><li class="footer__item"><a class="footer__link-item" href="/docs/domainModel/01main">Introduction</a></li><li class="footer__item"><a class="footer__link-item" href="/docs/quickStart/01quickstart">Installation</a></li><li class="footer__item"><a class="footer__link-item" href="/version">Migration from 4.x to 5.0</a></li></ul></div><div class="col footer__col"><div class="footer__title">Community</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://twitter.com/ApacheRocketMQ" target="_blank" rel="noopener noreferrer" class="footer__link-item">Twitter<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://github.com/apache/rocketmq" target="_blank" rel="noopener noreferrer" class="footer__link-item">Github</a></li><li class="footer__item"><a href="https://github.com/apache/rocketmq" target="_blank" rel="noopener noreferrer" class="footer__link-item">Help</a></li></ul></div><div class="col footer__col"><div class="footer__title">More</div><ul class="footer__items clean-list"><li class="footer__item"><a class="footer__link-item" href="/blog">Blog</a></li><li class="footer__item"><a class="footer__link-item" href="/release-notes">Changelog</a></li><li class="footer__item"><a href="https://github.com/apache/rocketmq" target="_blank" rel="noopener noreferrer" class="footer__link-item">GitHub<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://twitter.com/docusaurus" target="_blank" rel="noopener noreferrer" class="footer__link-item">Twitter<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li></ul></div><div class="col footer__col"><div class="footer__title">Legal</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://www.apache.org/licenses/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Licenses<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://www.apache.org/security/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Security<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://www.apache.org/foundation/thanks.html" target="_blank" rel="noopener noreferrer" class="footer__link-item">Thanks<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://www.apache.org/foundation/sponsorship.html" target="_blank" rel="noopener noreferrer" class="footer__link-item">Sponsorship<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li></ul></div></div><div class="footer__bottom text--center"><div class="margin-bottom--sm"><a href="https://rocketmq.apache.org/" rel="noopener noreferrer" class="footerLogoLink_BH7S"><img src="/img/Apache_RocketMQ_logo.svg.png" alt="Meta Open Source Logo" class="themedImage_ToTc themedImage--light_HNdA footer__logo"><img src="/img/Apache_RocketMQ_logo.svg.png" alt="Meta Open Source Logo" class="themedImage_ToTc themedImage--dark_i4oU footer__logo"></a></div><div class="footer__copyright">Copyright © 2022 The Apache Software Foundation. Licensed under the Apache License, Version 2.0.</div></div></div></footer></div> |
