| <!doctype html> |
| <html lang="en-US" dir="ltr" class="docs-wrapper docs-doc-page docs-version-current plugin-docs plugin-id-community docs-doc-id-design/metadata-design" data-has-hydrated="false"> |
| <head> |
| <meta charset="UTF-8"> |
| <meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no"> |
| <meta name="generator" content="Docusaurus v2.4.3"> |
| <link rel="alternate" type="application/rss+xml" href="/blog/rss.xml" title="Apache Doris RSS Feed"> |
| <link rel="alternate" type="application/atom+xml" href="/blog/atom.xml" title="Apache Doris Atom Feed"> |
| |
| <link rel="preconnect" href="https://www.google-analytics.com"> |
| <link rel="preconnect" href="https://www.googletagmanager.com"> |
| <script async src="https://www.googletagmanager.com/gtag/js?id=G-DT7W9E9722"></script> |
| <script>function gtag(){dataLayer.push(arguments)}window.dataLayer=window.dataLayer||[],gtag("js",new Date),gtag("config","G-DT7W9E9722",{anonymize_ip:!0})</script> |
| |
| |
| |
| <link rel="preconnect" href="https://analytics.apache.org/"> |
| <script>var _paq=window._paq=window._paq||[];_paq.push(["setRequestMethod","POST"]),_paq.push(["trackPageView"]),_paq.push(["enableLinkTracking"]),_paq.push(["enableHeartBeatTimer"]),function(){var e="https://analytics.apache.org/";_paq.push(["setRequestMethod","POST"]),_paq.push(["setTrackerUrl",e+"matomo.php"]),_paq.push(["setSiteId","43"]);var a=document,t=a.createElement("script"),p=a.getElementsByTagName("script")[0];t.type="text/javascript",t.async=!0,t.src=e+"matomo.js",p.parentNode.insertBefore(t,p)}()</script> |
| |
| |
| |
| <link rel="icon" href="/images/logo-only.png"> |
| <link rel="manifest" href="/manifest.json"> |
| <meta name="theme-color" content="#FFFFFF"> |
| <meta name="apple-mobile-web-app-capable" content="yes"> |
| <meta name="apple-mobile-web-app-status-bar-style" content="#000"> |
| <link rel="apple-touch-icon" href="/img/docusaurus.png"> |
| <link rel="mask-icon" href="/img/docusaurus.svg" color="rgb(37, 194, 160)"> |
| <meta name="msapplication-TileImage" content="/img/docusaurus.png"> |
| <meta name="msapplication-TileColor" content="#000"> |
| |
| |
| |
| <link rel="stylesheet" href="https://cdn-font.hyperos.mi.com/font/css?family=MiSans:100,200,300,400,450,500,600,650,700,900:Chinese_Simplify,Latin&display=swap"> |
| <link rel="stylesheet" href="https://cdn-font.hyperos.mi.com/font/css?family=MiSans_Latin:100,200,300,400,450,500,600,650,700,900:Latin&display=swap"> |
| <script src="/js/custom-script.js"></script><title data-rh="true">Metadata Design Document - Apache Doris</title><meta data-rh="true" name="viewport" content="width=device-width,initial-scale=1"><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:url" content="https://doris.apache.org/community/design/metadata-design"><meta data-rh="true" name="docusaurus_locale" content="en"><meta data-rh="true" name="docsearch:language" content="en"><meta data-rh="true" name="docusaurus_version" content="current"><meta data-rh="true" name="docusaurus_tag" content="docs-community-current"><meta data-rh="true" name="docsearch:version" content="current"><meta data-rh="true" name="docsearch:docusaurus_tag" content="docs-community-current"><meta data-rh="true" property="og:title" content="Metadata Design Document - Apache Doris"><meta data-rh="true" name="description" content="<!--"><meta data-rh="true" property="og:description" content="<!--"><link data-rh="true" rel="icon" href="/images/favicon.ico"><link data-rh="true" rel="canonical" href="https://doris.apache.org/community/design/metadata-design"><link data-rh="true" rel="alternate" href="https://doris.apache.org/community/design/metadata-design" hreflang="en-US"><link data-rh="true" rel="alternate" href="https://doris.apache.org/zh-CN/community/design/metadata-design" hreflang="zh-Hans-CN"><link data-rh="true" rel="alternate" href="https://doris.apache.org/community/design/metadata-design" hreflang="x-default"><link rel="stylesheet" href="https://cdnd.selectdb.com/assets/css/styles.2bd95c40.css"> |
| <link rel="preload" href="https://cdnd.selectdb.com/assets/js/runtime~main.eb208fba.js" as="script"> |
| <link rel="preload" href="https://cdnd.selectdb.com/assets/js/main.fa7fcb85.js" as="script"> |
| </head> |
| <body class="navigation-with-keyboard"> |
| <script>!function(){function t(t){document.documentElement.setAttribute("data-theme",t)}var e=function(){var t=null;try{t=new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}return t}()||function(){var t=null;try{t=localStorage.getItem("theme")}catch(t){}return t}();t(null!==e?e:"light")}(),document.documentElement.setAttribute("data-announcement-bar-initially-dismissed",function(){try{return"true"===localStorage.getItem("docusaurus.announcement.dismiss")}catch(t){}return!1}())</script><div id="__docusaurus"> |
| <div role="region" aria-label="Skip to main content"><a class="skipToContent_fXgn" href="#__docusaurus_skipToContent_fallback">Skip to main content</a></div><div class="announcementBar_s0pr" style="background-color:#3C2FD4;color:#FFFFFF" role="banner"><div class="announcementBarPlaceholder_qxfj"></div><div class="announcementBarContent_dpRF"><a href="https://github.com/apache/doris" target="_blank" style="display: flex; width: 100%; align-items: center; justify-content: center; margin-left: 4px; text-decoration: none; color: white">Do you ❤️ Doris? Give us a 🌟 on GitHub |
| <img style="width: 1.2rem; height: 1.2rem; margin-left: 0.4rem;" src="/images/github-white-icon.svg"> |
| </a></div><button type="button" class="clean-btn close announcementBarClose_iXyO" aria-label="Close"><svg viewBox="0 0 15 15" width="14" height="14" style="color:white"><g stroke="currentColor" stroke-width="3.1"><path d="M.75.75l13.5 13.5M14.25.75L.75 14.25"></path></g></svg></button></div><nav aria-label="Main" class="navbar navbar--fixed-top"><div class="navbar__inner" style="padding:"><div class="navbar__items"><div class="navbar-left"><div class="navbar-logo-wrapper flex items-center"><a class="navbar__brand" href="/"><div class="navbar__logo"><img src="https://cdnd.selectdb.com/images/logo.svg" alt="Apache Doris" class="themedImage_ToTc themedImage--light_HNdA"><img src="https://cdnd.selectdb.com/images/logo.svg" alt="Apache Doris" class="themedImage_ToTc themedImage--dark_i4oU"></div><b class="navbar__title text--truncate"></b></a></div><a class="navbar__item navbar__link" style="text-align:center" href="/docs/get-starting/quick-start">Docs</a><a class="navbar__item navbar__link" style="text-align:center" href="/blog">Blog</a><a class="navbar__item navbar__link" style="text-align:center" href="/users">Users</a><a href="https://github.com/apache/doris/discussions" target="_blank" rel="noopener noreferrer" class="navbar__item navbar__link" style="text-align:center">Discussions</a><a class="navbar__item navbar__link" style="text-align:center" href="/ecosystem/cluster-management">Ecosystem</a><a class="navbar__item navbar__link" style="text-align:center" href="/community/join-community">Community</a></div></div><div class="navbar__items navbar__items--right"><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><div class="docs-search searchBox_H2mL"><div class="navbar__search searchBarContainer_PzyC"><input placeholder="Search" aria-label="Search" class="navbar__search-input navbarSearchInput_tb6T"><div class="loadingRing__K5d searchBarLoadingRing_e2f0"><div></div><div></div><div></div><div></div></div><div class="searchHintContainer_m7ml"><kbd class="searchHint_zuPL">ctrl</kbd><kbd class="searchHint_zuPL">K</kbd></div></div></div><div class="custom-navbar-item navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link"><svg class="icon-language" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16" fill="none"><path d="M7.75756 14.3L10.5816 6.91667H11.8759L14.7 14.3H13.4057L12.7501 12.4167H9.74113L9.06873 14.3H7.75756ZM10.1109 11.35H12.3467L11.254 8.3H11.2036L10.1109 11.35ZM2.84908 12.45L1.97498 11.5833L5.11841 8.48333C4.72618 8.05 4.38439 7.60267 4.09302 7.14133C3.80165 6.68044 3.54389 6.19444 3.31976 5.68333H4.61412C4.80463 6.06111 5.00635 6.39711 5.21927 6.69133C5.43219 6.986 5.68434 7.29444 5.97571 7.61667C6.43519 7.12778 6.81621 6.62511 7.11879 6.10867C7.42137 5.59178 7.67352 5.03889 7.87523 4.45H1V3.23333H5.33694V2H6.58087V3.23333H10.9178V4.45H9.11916C8.89503 5.18333 8.59805 5.89155 8.22824 6.57467C7.85842 7.25822 7.39895 7.90555 6.84983 8.51667L8.3459 10.0167L7.87523 11.2833L5.95891 9.38333L2.84908 12.45Z" fill="#4C576C"></path></svg></a><ul class="dropdown__menu"><li><a href="/community/design/metadata-design" target="_self" rel="noopener noreferrer" class="dropdown__link dropdown__link--active" style="text-align:center">English</a></li><li><a href="/zh-CN/community/design/metadata-design" target="_self" rel="noopener noreferrer" class="dropdown__link" style="text-align:center">中文</a></li></ul></div><div class="custom-navbar-item navbar__item dropdown dropdown--hoverable dropdown--right"><a class="navbar__link" aria-haspopup="true" aria-expanded="false" role="button" href="/docs/get-starting/what-is-apache-doris"><span class="text-sm">Versions: </span></a><ul class="dropdown__menu"><li><a class="dropdown__link" style="text-align:center" href="/docs/dev/get-starting/what-is-apache-doris">Dev</a></li><li><a class="dropdown__link" style="text-align:center" href="/docs/get-starting/what-is-apache-doris">2.1</a></li><li><a class="dropdown__link" style="text-align:center" href="/docs/2.0/get-starting/what-is-apache-doris">2.0</a></li><li><a class="dropdown__link" style="text-align:center" href="/docs/1.2/get-starting/">1.2</a></li></ul></div><a class="navbar__item navbar__link header-right-button-primary navbar-download-mobile" style="text-align:center" href="/download">Download</a><a href="https://github.com/apache/doris" target="_blank" rel="noopener noreferrer" class="github-btn desktop header-right-button-github"></a><a href="https://join.slack.com/t/apachedoriscommunity/shared_invite/zt-2kl08hzc0-SPJe4VWmL_qzrFd2u2XYQA" target="_blank" rel="noopener noreferrer" class="slack-btn desktop header-right-button-slack"></a><a class="header-right-button-primary navbar-download-desktop" href="/download">Download</a></div></div><div class="navbar__bottom"></div><div role="presentation" class="navbar-sidebar__backdrop"></div></nav><div id="__docusaurus_skipToContent_fallback" class="main-wrapper mainWrapper_z2l0"><div role="region" aria-label="Skip to main content"><a class="skipToContent_fXgn" href="#__docusaurus_skipToContent_fallback">Skip to main content</a></div><div class="main-wrapper 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"><nav aria-label="Docs sidebar" class="menu custom-scrollbar menu_Y1UP menuWithAnnouncementBar_fPny"><ul class="theme-doc-sidebar-menu menu__list"><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/join-community">Join Community</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/subscribe-mail-list">Subscribe Mailing Lists</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/feedback">Feedback</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/doris-future">Doris Future Project</a></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 id="menu__group" class="menu__link menu__link_level_1 menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/community/how-to-contribute/">How to Contribute</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 id="menu__group" class="menu__link menu__link_level_1 menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/community/release-and-verify/release-prepare">Release Process & Verification</a></div></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/security">Security</a></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class="menu__list-item-collapsible"><a id="menu__group" class="menu__link menu__link_level_1 menu__link--sublist menu__link--sublist-caret menu__link--active" aria-expanded="true" href="/community/design/doris_storage_optimization">Design Documents</a></div><ul style="display:block;overflow:visible;height:auto" class="menu__list menu__list_level_2"><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/community/design/doris_storage_optimization">Doris Storage File Format Optimization</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="/community/design/grouping_sets_design">GROUPING SETS Design</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="/community/design/metadata-design">Metadata Design Document</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="/community/design/spark_load">Spark Load</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 id="menu__group" class="menu__link menu__link_level_1 menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/community/developer-guide/debug-tool">Developer Guide</a></div></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/community/team">Doris Team</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a href="https://cwiki.apache.org/confluence/display/DORIS/Doris+Improvement+Proposals" target="_blank" rel="noopener noreferrer" class="menu__link menuExternalLink_NmtK">Improvement Proposals<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></nav></div></div></aside><main class="docMainContainer_gTbr"><div class="container padding-top--md padding-bottom--lg"><div class="row"><div class="col docItemCol_z5aJ"><div class="docItemContainer_c0TR"><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">Design Documents</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">Metadata Design Document</span><meta itemprop="position" content="2"></li></ul></nav><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"><header><h1>Metadata Design Document</h1></header><h1>Metadata Design Document</h1><h2 class="anchor anchorWithStickyNavbar_LWe7" id="noun-interpretation">Noun Interpretation<a href="#noun-interpretation" class="hash-link" aria-label="Direct link to Noun Interpretation" title="Direct link to Noun Interpretation"></a></h2><ul><li>FE: Frontend, the front-end node of Doris. Mainly responsible for receiving and returning client requests, metadata, cluster management, query plan generation and so on.</li><li>BE: Backend, the back-end node of Doris. Mainly responsible for data storage and management, query plan execution and other work.</li><li>bdbje: <a href="http://www.oracle.com/technetwork/database/berkeleydb/overview/index-093405.html" target="_blank" rel="noopener noreferrer">Oracle Berkeley DB Java Edition</a>. In Doris, we use bdbje to persist metadata operation logs and high availability of FE.</li></ul><h2 class="anchor anchorWithStickyNavbar_LWe7" id="overall-architecture">Overall architecture<a href="#overall-architecture" class="hash-link" aria-label="Direct link to Overall architecture" title="Direct link to Overall architecture"></a></h2><p><img loading="lazy" src="https://cdnd.selectdb.com/assets/images/palo_architecture-fc338e36ab7b7d4cc12992b146e63b7e.jpg" width="1494" height="780" class="img_ev3q"></p><p>As shown above, Doris's overall architecture is divided into two layers. Multiple FEs form the first tier, providing lateral expansion and high availability of FE. Multiple BEs form the second layer, which is responsible for data storage and management. This paper mainly introduces the design and implementation of metadata in FE layer.</p><ol><li><p>There are two different kinds of FE nodes: follower and observer. Leader election and data synchronization are taken among FE nodes by bdbje (<a href="http://www.oracle.com/technetwork/database/database-technologies/berkeleydb/overview/index-093405.html" target="_blank" rel="noopener noreferrer">BerkeleyDB Java Edition</a>).</p></li><li><p>The follower node is elected, and one of the followers becomes the leader node, which is responsible for the writing of metadata. When the leader node goes down, other follower nodes re-elect a leader to ensure high availability of services.</p></li><li><p>The observer node only synchronizes metadata from the leader node and does not participate in the election. It can be scaled horizontally to provide the extensibility of metadata reading services.</p></li></ol><blockquote><p>Note: The concepts of follower and observer corresponding to bdbje are replica and observer. You may use both names below.</p></blockquote><h2 class="anchor anchorWithStickyNavbar_LWe7" id="metadata-structure">Metadata structure<a href="#metadata-structure" class="hash-link" aria-label="Direct link to Metadata structure" title="Direct link to Metadata structure"></a></h2><p>Doris's metadata is in full memory. A complete metadata image is maintained in each FE memory. Within Baidu, a cluster of 2,500 tables and 1 million fragments (3 million copies) occupies only about 2GB of metadata in memory. (Of course, the memory overhead for querying intermediate objects and various job information needs to be estimated according to the actual situation. However, it still maintains a low memory overhead.</p><p>At the same time, metadata is stored in the memory as a whole in a tree-like hierarchical structure. By adding auxiliary structure, metadata information at all levels can be accessed quickly.</p><p>The following figure shows the contents stored in Doris meta-information.</p><p><img loading="lazy" src="https://cdnd.selectdb.com/assets/images/metadata_contents-350e796e1ccf823f17af7ffb6a1007f8.png" width="487" height="168" class="img_ev3q"></p><p>As shown above, Doris's metadata mainly stores four types of data:</p><ol><li>User data information. Including database, table Schema, fragmentation information, etc.</li><li>All kinds of job information. For example, import jobs, Clone jobs, SchemaChange jobs, etc.</li><li>User and permission information.</li><li>Cluster and node information.</li></ol><h2 class="anchor anchorWithStickyNavbar_LWe7" id="data-stream">Data stream<a href="#data-stream" class="hash-link" aria-label="Direct link to Data stream" title="Direct link to Data stream"></a></h2><p><img loading="lazy" src="https://cdnd.selectdb.com/assets/images/metadata_stream-7732a2fc872dd349c79d964b8425bcda.png" width="1055" height="428" class="img_ev3q"></p><p>The data flow of metadata is as follows:</p><ol><li><p>Only leader FE can write metadata. After modifying leader's memory, the write operation serializes into a log and writes to bdbje in the form of key-value. The key is a continuous integer, and as log id, value is the serialized operation log.</p></li><li><p>After the log is written to bdbje, bdbje copies the log to other non-leader FE nodes according to the policy (write most/write all). The non-leader FE node modifies its metadata memory image by playback of the log, and completes the synchronization with the metadata of the leader node.</p></li><li><p>The number of log entries of the leader node reaches the threshold (default 10w) and meets the checkpoint thread execution cycle (default 60 seconds). Checkpoint reads existing image files and subsequent logs and replays a new mirror copy of metadata in memory. The copy is then written to disk to form a new image. The reason for this is to regenerate a mirror copy instead of writing an existing image to an image, mainly considering that the write operation will be blocked during writing the image plus read lock. So every checkpoint takes up twice as much memory space.</p></li><li><p>After the image file is generated, the leader node notifies other non-leader nodes that a new image has been generated. Non-leader actively pulls the latest image files through HTTP to replace the old local files.</p></li><li><p>The logs in bdbje will be deleted regularly after the image is completed.</p></li></ol><h2 class="anchor anchorWithStickyNavbar_LWe7" id="implementation-details">Implementation details<a href="#implementation-details" class="hash-link" aria-label="Direct link to Implementation details" title="Direct link to Implementation details"></a></h2><h3 class="anchor anchorWithStickyNavbar_LWe7" id="metadata-catalogue">Metadata catalogue<a href="#metadata-catalogue" class="hash-link" aria-label="Direct link to Metadata catalogue" title="Direct link to Metadata catalogue"></a></h3><ol><li><p>The metadata directory is specified by the FE configuration item `meta_dir'.</p></li><li><p>Data storage directory for bdbje under <code>bdb/</code> directory.</p></li><li><p>The storage directory for image files under the <code>image/</code> directory.</p></li></ol><ul><li><code>Image.[logid]</code>is the latest image file. The suffix <code>logid</code> indicates the ID of the last log contained in the image.</li><li><code>Image.ckpt</code> is the image file being written. If it is successfully written, it will be renamed <code>image.[logid]</code> and replaced with the original image file.</li><li>The<code>cluster_id</code> is recorded in the <code>VERSION</code> file. <code>Cluster_id</code> uniquely identifies a Doris cluster. It is a 32-bit integer randomly generated at the first startup of leader. You can also specify a cluster ID through the Fe configuration item `cluster_id'.</li><li>The role of FE itself recorded in the <code>ROLE</code> file. There are only <code>FOLLOWER</code> and <code>OBSERVER</code>. Where <code>FOLLOWER</code> denotes FE as an optional node. (Note: Even the leader node has a role of <code>FOLLOWER</code>)</li></ul><h3 class="anchor anchorWithStickyNavbar_LWe7" id="start-up-process">Start-up process<a href="#start-up-process" class="hash-link" aria-label="Direct link to Start-up process" title="Direct link to Start-up process"></a></h3><ol><li><p>FE starts for the first time. If the startup script does not add any parameters, it will try to start as leader. You will eventually see <code>transfer from UNKNOWN to MASTER</code> in the FE startup log.</p></li><li><p>FE starts for the first time. If the <code>--helper</code> parameter is specified in the startup script and points to the correct leader FE node, the FE first asks the leader node about its role (ROLE) and cluster_id through http. Then pull up the latest image file. After reading image file and generating metadata image, start bdbje and start bdbje log synchronization. After synchronization is completed, the log after image file in bdbje is replayed, and the final metadata image generation is completed.</p><blockquote><p>Note 1: When starting with the <code>--helper</code> parameter, you need to first add the FE through the leader through the MySQL command, otherwise, the start will report an error.</p></blockquote><blockquote><p>Note 2: <code>--helper</code> can point to any follower node, even if it is not leader.</p></blockquote><blockquote><p>Note 3: In the process of synchronization log, the Fe log will show <code>xxx detached</code>. At this time, the log pull is in progress, which is a normal phenomenon.</p></blockquote></li><li><p>FE is not the first startup. If the startup script does not add any parameters, it will determine its identity according to the ROLE information stored locally. At the same time, according to the cluster information stored in the local bdbje, the leader information is obtained. Then read the local image file and the log in bdbje to complete the metadata image generation. (If the roles recorded in the local ROLE are inconsistent with those recorded in bdbje, an error will be reported.)</p></li><li><p>FE is not the first boot, and the <code>--helper</code> parameter is specified in the boot script. Just like the first process started, the leader role is asked first. But it will be compared with the ROLE stored by itself. If they are inconsistent, they will report errors.</p></li></ol><h4 class="anchor anchorWithStickyNavbar_LWe7" id="metadata-read-write-and-synchronization">Metadata Read-Write and Synchronization<a href="#metadata-read-write-and-synchronization" class="hash-link" aria-label="Direct link to Metadata Read-Write and Synchronization" title="Direct link to Metadata Read-Write and Synchronization"></a></h4><ol><li><p>Users can use Mysql to connect any FE node to read and write metadata. If the connection is a non-leader node, the node forwards the write operation to the leader node. When the leader is successfully written, it returns a current and up-to-date log ID of the leader. Later, the non-leader node waits for the log ID it replays to be larger than the log ID it returns to the client before returning the message that the command succeeds. This approach guarantees Read-Your-Write semantics for any FE node.</p><blockquote><p>Note: Some non-write operations are also forwarded to leader for execution. For example, <code>SHOW LOAD</code> operation. Because these commands usually need to read the intermediate states of some jobs, which are not written to bdbje, there are no such intermediate states in the memory of the non-leader node. (FE's direct metadata synchronization depends entirely on bdbje's log playback. If a metadata modification operation does not write bdbje's log, the result of the modification of the operation will not be seen in other non-leader nodes.)</p></blockquote></li><li><p>The leader node starts a TimePrinter thread. This thread periodically writes a key-value entry for the current time to bdbje. The remaining non-leader nodes read the recorded time in the log by playback and compare it with the local time. If the lag between the local time and the local time is found to be greater than the specified threshold (configuration item: <code>meta_delay_toleration_second</code>). If the write interval is half of the configuration item, the node will be in the <strong>unreadable</strong> state. This mechanism solves the problem that non-leader nodes still provide outdated metadata services after a long time of leader disconnection.</p></li><li><p>The metadata of each FE only guarantees the final consistency. Normally, inconsistent window periods are only milliseconds. We guarantee the monotonous consistency of metadata access in the same session. But if the same client connects different FEs, metadata regression may occur. (But for batch update systems, this problem has little impact.)</p></li></ol><h3 class="anchor anchorWithStickyNavbar_LWe7" id="downtime-recovery">Downtime recovery<a href="#downtime-recovery" class="hash-link" aria-label="Direct link to Downtime recovery" title="Direct link to Downtime recovery"></a></h3><ol><li>When the leader node goes down, the rest of the followers will immediately elect a new leader node to provide services.</li><li>Metadata cannot be written when most follower nodes are down. When metadata is not writable, if a write operation request occurs, the current process is that the <strong>FE process exits</strong>. This logic will be optimized in the future, and read services will still be provided in the non-writable state.</li><li>The downtime of observer node will not affect the state of any other node. It also does not affect metadata reading and writing at other nodes.</li></ol></div></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href="/community/design/grouping_sets_design"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">GROUPING SETS Design</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/community/design/spark_load"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">Spark Load</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_jeP5 thin-scrollbar theme-doc-toc-desktop"><a href="https://github.com/apache/doris/discussions" target="_blank" rel="noopener noreferrer" class="ml-4 mb-8 flex items-center hover:no-underline"><span class="pr-2">Join Discussion</span><svg viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" p-id="8500" id="mx_n_1711090272569" width="16" height="16"><path d="M522.24 896.512c-25.6 4.608-51.712 7.168-78.336 7.168-79.36 0-157.696-21.504-225.792-62.464l-18.432-10.752-103.936 28.16c-28.672 7.68-54.784-18.432-47.104-47.104l28.16-103.936c-10.752-17.92-17.408-30.208-20.992-36.864C20.992 607.232 3.072 536.064 3.584 463.36c0-243.2 197.12-440.32 440.32-440.32 221.696 0 405.504 164.352 435.712 377.856 90.112 55.808 144.896 154.112 144.896 260.096 0 51.2-12.8 100.352-36.352 144.384-2.048 4.096-6.144 10.752-11.776 20.48l17.408 64c7.68 28.672-18.432 54.784-47.104 47.104l-64-17.408-7.68 4.608c-47.616 28.672-101.888 43.52-157.184 43.52-71.68-0.512-140.8-25.088-195.584-71.168z m95.232-28.672c31.232 15.36 65.536 23.04 100.352 23.04 41.472 0 82.432-11.264 117.76-32.768 2.56-1.536 9.728-5.632 22.016-12.8 8.704-5.12 19.456-6.656 29.184-3.584l14.848 4.096-4.096-14.848c-2.56-10.24-1.536-20.48 4.096-29.696 6.144-10.24 12.288-20.992 18.432-31.232 17.92-33.28 27.136-70.656 27.136-108.544 0-59.904-23.552-117.76-65.536-160.256-13.312 164.352-118.272 303.616-264.192 366.592z m-462.848-155.648l-14.848 54.784 54.784-14.848c9.728-2.56 20.48-1.536 29.184 4.096 18.432 10.752 29.184 16.896 32.768 19.456 56.32 33.792 120.832 51.712 186.88 51.712 200.704 0 363.52-162.816 363.52-363.52s-162.816-363.52-363.52-363.52-363.52 162.816-363.52 363.52c0 60.928 14.848 119.296 43.008 171.52 3.584 7.168 13.312 23.04 27.648 47.616 5.632 8.704 6.656 19.456 4.096 29.184z m448.512-382.976c20.992 0 38.4 16.896 38.4 38.4 0 20.992-16.896 38.4-38.4 38.4H284.16c-20.992 0-38.4-16.896-38.4-38.4 0-20.992 16.896-38.4 38.4-38.4h318.976z m-153.088 191.488c20.992 0 38.4 16.896 38.4 38.4 0 20.992-16.896 38.4-38.4 38.4H284.16c-20.992 0-38.4-16.896-38.4-38.4 0-20.992 16.896-38.4 38.4-38.4h165.888z m0 0" p-id="8501" fill="currentColor"></path></svg></a><span class="ml-4">On This Page</span><ul class="table-of-contents table-of-contents__left-border"><li><a href="#noun-interpretation" class="table-of-contents__link toc-highlight">Noun Interpretation</a></li><li><a href="#overall-architecture" class="table-of-contents__link toc-highlight">Overall architecture</a></li><li><a href="#metadata-structure" class="table-of-contents__link toc-highlight">Metadata structure</a></li><li><a href="#data-stream" class="table-of-contents__link toc-highlight">Data stream</a></li><li><a href="#implementation-details" class="table-of-contents__link toc-highlight">Implementation details</a><ul><li><a href="#metadata-catalogue" class="table-of-contents__link toc-highlight">Metadata catalogue</a></li><li><a href="#start-up-process" class="table-of-contents__link toc-highlight">Start-up process</a></li><li><a href="#downtime-recovery" class="table-of-contents__link toc-highlight">Downtime recovery</a></li></ul></li></ul></div></div></div></div></main></div></div></div><div class="footer pt-16 pb-10"><div class="container"><div class="footer-box"><div class="left"><img src="/images/asf_logo_apache.svg" alt="" class="themedImage_ToTc themedImage--light_HNdA footer__logo"><img src="/images/asf_logo_apache.svg" alt="" class="themedImage_ToTc themedImage--dark_i4oU footer__logo"><div class="row footer__links"><div class="col footer__col"><div class="footer__title">ASF</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://www.apache.org/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Foundation<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/licenses/" target="_blank" rel="noopener noreferrer" class="footer__link-item">License<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/events/current-event" target="_blank" rel="noopener noreferrer" class="footer__link-item">Events<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><li class="footer__item"><a href="https://privacy.apache.org/policies/privacy-policy-public.html" target="_blank" rel="noopener noreferrer" class="footer__link-item">Privacy<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></ul></div><div class="col footer__col"><div class="footer__title">Resources</div><ul class="footer__items clean-list"><li class="footer__item"><a class="footer__link-item" href="/download">Download</a></li><li class="footer__item"><a class="footer__link-item" href="/docs/get-starting/quick-start">Docs</a></li><li class="footer__item"><a class="footer__link-item" href="/blog">Blog</a></li><li class="footer__item"><a class="footer__link-item" href="/ecosystem/cluster-management">Ecosystem</a></li><li class="footer__item"><a class="footer__link-item" href="/users">Users</a></li><li class="footer__item"><a href="https://github.com/apache/doris/discussions" target="_blank" rel="noopener noreferrer" class="footer__link-item">Discussions<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">Community</div><ul class="footer__items clean-list"><li class="footer__item"><a class="footer__link-item" href="/community/how-to-contribute/">How to contribute</a></li><li class="footer__item"><a href="https://github.com/apache/doris/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Source code<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://cwiki.apache.org/confluence/display/DORIS/Doris+Improvement+Proposals" target="_blank" rel="noopener noreferrer" class="footer__link-item">Improvement proposal<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 class="footer__link-item" href="/community/team">Doris team</a></li><li class="footer__item"><a href="https://github.com/apache/doris/issues/30669" target="_blank" rel="noopener noreferrer" class="footer__link-item">Roadmap<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><div class="right"><div class="footer__title">Join the community</div><div class="social-list"><div class="social"><a href="mailto:dev@doris.apache.org" target="_blank" title="mail" class="item"><svg xmlns="http://www.w3.org/2000/svg" width="2em" height="2em" viewBox="0 0 32 32" fill="none"><path d="M5.6003 6H26.3997C27.8186 6 28.982 7.10964 29 8.46946L16.0045 15.454L3.01202 8.47829C3.02405 7.11258 4.1784 6 5.6003 6ZM3.01202 11.1508L3 23.5011C3 24.8756 4.16938 26 5.6003 26H26.3997C27.8306 26 29 24.8756 29 23.5011V11.145L16.3111 17.8028C16.1157 17.9058 15.8813 17.9058 15.6889 17.8028L3.01202 11.1508Z" fill="currentColor"></path></svg></a><a href="https://github.com/apache/doris" target="_blank" title="github" class="item"><svg width="2em" height="2em" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg"><path d="M16.0001 2.66675C8.63342 2.66675 2.66675 8.63341 2.66675 16.0001C2.66524 18.7991 3.54517 21.5276 5.1817 23.7983C6.81824 26.0691 9.12828 27.7668 11.7841 28.6508C12.4508 28.7668 12.7001 28.3668 12.7001 28.0161C12.7001 27.7001 12.6828 26.6508 12.6828 25.5334C9.33342 26.1508 8.46675 24.7174 8.20008 23.9668C8.04942 23.5828 7.40008 22.4001 6.83342 22.0828C6.36675 21.8334 5.70008 21.2161 6.81608 21.2001C7.86675 21.1828 8.61608 22.1668 8.86675 22.5668C10.0668 24.5828 11.9841 24.0161 12.7494 23.6668C12.8668 22.8001 13.2161 22.2174 13.6001 21.8841C10.6334 21.5508 7.53342 20.4001 7.53342 15.3001C7.53342 13.8494 8.04942 12.6507 8.90008 11.7161C8.76675 11.3827 8.30008 10.0161 9.03342 8.18275C9.03342 8.18275 10.1494 7.83342 12.7001 9.55075C13.7855 9.2495 14.907 9.09787 16.0334 9.10008C17.1668 9.10008 18.3001 9.24942 19.3668 9.54942C21.9161 7.81608 23.0334 8.18408 23.0334 8.18408C23.7668 10.0174 23.3001 11.3841 23.1668 11.7174C24.0161 12.6507 24.5334 13.8334 24.5334 15.3001C24.5334 20.4174 21.4174 21.5508 18.4508 21.8841C18.9334 22.3001 19.3508 23.1001 19.3508 24.3508C19.3508 26.1334 19.3334 27.5668 19.3334 28.0174C19.3334 28.3668 19.5841 28.7828 20.2508 28.6494C22.8975 27.7558 25.1973 26.0547 26.8266 23.7856C28.4559 21.5165 29.3327 18.7936 29.3334 16.0001C29.3334 8.63341 23.3668 2.66675 16.0001 2.66675V2.66675Z" fill="currentColor"></path></svg></a><a href="https://twitter.com/doris_apache" target="_blank" title="twitter" class="item"><svg xmlns="http://www.w3.org/2000/svg" width="2em" height="2em" viewBox="0 0 32 32" fill="none"><path d="M4.625 4.625H11.2809L27.375 27.375H20.7191L4.625 4.625ZM7.52549 6.10639L21.5236 25.8936H24.4746L10.4764 6.10639H7.52549Z" fill="currentColor"></path><path d="M14.4268 18.4803L6.53447 27.375H4.625L13.5581 17.2525L14.4268 18.4803ZM18.1299 14.3066L26.7203 4.625H24.7017L17.2525 13.0662L18.1299 14.3066Z" fill="currentColor"></path></svg></a><a href="https://join.slack.com/t/apachedoriscommunity/shared_invite/zt-2kl08hzc0-SPJe4VWmL_qzrFd2u2XYQA" title="slack" target="_blank" class="item"><svg width="2em" height="2em" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg"><g clip-path="url(#clip0_125_278)"><path d="M12.5875 16.6906C11.0844 16.6906 9.86562 17.9094 9.86562 19.4125V26.2375C9.86562 26.9594 10.1524 27.6517 10.6628 28.1622C11.1733 28.6726 11.8656 28.9594 12.5875 28.9594C13.3094 28.9594 14.0017 28.6726 14.5122 28.1622C15.0226 27.6517 15.3094 26.9594 15.3094 26.2375V19.4531C15.3094 17.9094 14.0906 16.6906 12.5875 16.6906ZM3 19.4531C3 20.175 3.28677 20.8673 3.79722 21.3778C4.30767 21.8882 4.99999 22.175 5.72187 22.175C6.44376 22.175 7.13608 21.8882 7.64653 21.3778C8.15698 20.8673 8.44375 20.175 8.44375 19.4531V16.7312H5.7625C4.25938 16.6906 3 17.9094 3 19.4531ZM12.5875 3C11.8656 3 11.1733 3.28677 10.6628 3.79722C10.1524 4.30767 9.86562 4.99999 9.86562 5.72187C9.86562 6.44376 10.1524 7.13608 10.6628 7.64653C11.1733 8.15698 11.8656 8.44375 12.5875 8.44375H15.3094V5.72187C15.3094 4.21875 14.0906 3 12.5875 3ZM5.72187 15.3094H12.5469C13.2688 15.3094 13.9611 15.0226 14.4715 14.5122C14.982 14.0017 15.2688 13.3094 15.2688 12.5875C15.2688 11.8656 14.982 11.1733 14.4715 10.6628C13.9611 10.1524 13.2688 9.86562 12.5469 9.86562H5.72187C4.99999 9.86562 4.30767 10.1524 3.79722 10.6628C3.28677 11.1733 3 11.8656 3 12.5875C3 13.3094 3.28677 14.0017 3.79722 14.5122C4.30767 15.0226 4.99999 15.3094 5.72187 15.3094ZM26.2375 9.86562C24.7344 9.86562 23.5156 11.0844 23.5156 12.5875V15.3094H26.2375C26.9594 15.3094 27.6517 15.0226 28.1622 14.5122C28.6726 14.0017 28.9594 13.3094 28.9594 12.5875C28.9594 11.8656 28.6726 11.1733 28.1622 10.6628C27.6517 10.1524 26.9594 9.86562 26.2375 9.86562ZM16.6906 5.72187V12.5875C16.6906 13.3094 16.9774 14.0017 17.4878 14.5122C17.9983 15.0226 18.6906 15.3094 19.4125 15.3094C20.1344 15.3094 20.8267 15.0226 21.3372 14.5122C21.8476 14.0017 22.1344 13.3094 22.1344 12.5875V5.72187C22.1344 4.99999 21.8476 4.30767 21.3372 3.79722C20.8267 3.28677 20.1344 3 19.4125 3C18.6906 3 17.9983 3.28677 17.4878 3.79722C16.9774 4.30767 16.6906 4.99999 16.6906 5.72187ZM22.1344 26.2781C22.1344 24.775 20.9156 23.5562 19.4125 23.5562H16.6906V26.2781C16.6906 27 16.9774 27.6923 17.4878 28.2028C17.9983 28.7132 18.6906 29 19.4125 29C20.1344 29 20.8267 28.7132 21.3372 28.2028C21.8476 27.6923 22.1344 27 22.1344 26.2781ZM26.2781 16.6906H19.4125C18.6906 16.6906 17.9983 16.9774 17.4878 17.4878C16.9774 17.9983 16.6906 18.6906 16.6906 19.4125C16.6906 20.1344 16.9774 20.8267 17.4878 21.3372C17.9983 21.8476 18.6906 22.1344 19.4125 22.1344H26.2375C27.7406 22.1344 28.9594 20.9156 28.9594 19.4125C29 17.9094 27.7812 16.6906 26.2781 16.6906Z" fill="currentColor"></path></g><defs><clipPath id="clip0_125_278"><rect width="26" height="26" fill="currentColor" transform="translate(3 3)"></rect></clipPath></defs></svg></a></div><div class="social"><a href="https://www.youtube.com/@apachedoris/channels" title="youtube" target="_blank" class="item"><svg xmlns="http://www.w3.org/2000/svg" width="2em" height="2em" viewBox="0 0 32 32" fill="none"><path d="M28.5167 7.83429C28.9436 8.25423 29.2532 8.77539 29.4154 9.34742C29.8205 11.5462 30.0159 13.7775 29.999 16.0121C30.0144 18.2382 29.819 20.4609 29.4154 22.6515C29.2532 23.2235 28.9436 23.7446 28.5167 24.1645C28.0898 24.5845 27.5601 24.889 26.9785 25.0486C24.7728 25.625 16.0124 25.625 16.0124 25.625C16.0124 25.625 7.22652 25.625 5.04638 25.0486C4.46489 24.889 3.9351 24.5845 3.5082 24.1645C3.08132 23.7446 2.77176 23.2235 2.60948 22.6515C2.19736 20.4617 1.9934 18.239 2.00025 16.0121C1.9918 13.7767 2.19577 11.5455 2.60948 9.34742C2.77176 8.77539 3.08132 8.25423 3.5082 7.83429C3.9351 7.41436 4.46489 7.10985 5.04638 6.95021C7.25103 6.36354 16.0124 6.37502 16.0124 6.37502C16.0124 6.37502 24.796 6.37502 26.9785 6.95021C27.5601 7.10985 28.0898 7.41436 28.5167 7.83429ZM12.5 21.25L21.25 16.008L12.5 10.75V21.25Z" fill="currentColor"></path></svg></a><a href="https://www.linkedin.com/company/doris-apache/" title="linkedin" target="_blank" class="item"><svg width="2rem" height="2rem" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg"><path d="M4.29925 26.9996H9.66738V11.6781H4.29925V26.9996ZM22.1628 11.1949C19.9409 11.1949 18.7157 11.9388 17.3054 13.7407V11.6777H11.9459V26.9996H17.305V18.6738C17.305 16.9168 18.145 15.1982 20.1535 15.1982C22.162 15.1982 22.6559 16.9164 22.6559 18.632V27H28V18.2902C28 12.2386 24.3854 11.1949 22.1628 11.1949ZM6.99325 4C5.3395 4 4 5.21047 4 6.7046C4 8.19759 5.3395 9.40617 6.99325 9.40617C8.6455 9.40617 9.985 8.19722 9.985 6.7046C9.985 5.21047 8.6455 4 6.99325 4Z" fill="white"></path></svg></a><a href="https://medium.com/@ApacheDoris" title="medium" target="_blank" class="item"><svg width="2em" height="2em" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg"><g id="Frame"><path id="Vector" d="M17.7967 16.5385C17.8029 18.53 16.9746 20.4425 15.4937 21.8559C14.0128 23.2693 12.0004 24.0681 9.89836 24.0769C7.79633 24.0681 5.78391 23.2693 4.30302 21.8559C2.82212 20.4425 1.99383 18.53 2.00003 16.5385C1.99383 14.5469 2.82212 12.6344 4.30302 11.221C5.78391 9.80759 7.79633 9.00878 9.89836 9C12.0004 9.00878 14.0128 9.80759 15.4937 11.221C16.9746 12.6344 17.8029 14.5469 17.7967 16.5385ZM26.4533 16.5385C26.4533 20.4514 24.6917 23.6348 22.51 23.6348C20.3283 23.6348 18.555 20.4514 18.555 16.5385C18.555 12.6255 20.3283 9.44214 22.51 9.44214C24.6917 9.44214 26.4533 12.6255 26.4533 16.5385ZM30 16.5385C30 20.0424 29.3817 22.8942 28.6117 22.8942C27.8417 22.8942 27.2233 20.0424 27.2233 16.5385C27.2233 13.0345 27.8417 10.1827 28.6117 10.1827C29.3817 10.1827 30 13.0345 30 16.5385Z" fill="currentColor"></path></g></svg></a><a class="item wechat"><svg width="2em" height="2em" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg"><path d="M20.7578 11.5169C21.0708 11.5169 21.3795 11.5398 21.6851 11.573C20.8524 7.73517 16.7052 4.88306 11.9718 4.88306C6.67951 4.88306 2.34412 8.45283 2.34412 12.9854C2.34412 15.6013 3.78679 17.7498 6.19667 19.4161L5.2339 22.2827L8.59917 20.6122C9.80411 20.8478 10.7698 21.0906 11.9718 21.0906C12.2738 21.0906 12.5728 21.0759 12.8703 21.0523C12.682 20.4159 12.5728 19.7485 12.5728 19.0566C12.5728 14.8947 16.1847 11.5169 20.7578 11.5169ZM15.5822 8.9335C16.3072 8.9335 16.7871 9.40601 16.7871 10.1229C16.7871 10.8369 16.3072 11.3153 15.5822 11.3153C14.8601 11.3153 14.1365 10.8369 14.1365 10.1229C14.1365 9.40601 14.8601 8.9335 15.5822 8.9335ZM8.84429 11.3153C8.12218 11.3153 7.3942 10.8368 7.3942 10.1229C7.3942 9.40597 8.12218 8.93346 8.84429 8.93346C9.56559 8.93346 10.0463 9.40597 10.0463 10.1229C10.0463 10.8369 9.56559 11.3153 8.84429 11.3153ZM29.5453 18.9422C29.5453 15.1332 25.6935 12.0285 21.3677 12.0285C16.7871 12.0285 13.1797 15.1332 13.1797 18.9422C13.1797 22.7567 16.7871 25.8547 21.3677 25.8547C22.326 25.8547 23.2932 25.6169 24.2559 25.3777L26.897 26.8086L26.1726 24.4282C28.1056 22.993 29.5453 21.0906 29.5453 18.9422ZM18.7126 17.7498C18.2335 17.7498 17.7499 17.278 17.7499 16.7966C17.7499 16.3219 18.2335 15.8442 18.7126 15.8442C19.4406 15.8442 19.9176 16.3219 19.9176 16.7966C19.9176 17.278 19.4406 17.7498 18.7126 17.7498ZM24.0079 17.7498C23.5324 17.7498 23.0518 17.278 23.0518 16.7966C23.0518 16.3219 23.5324 15.8442 24.0079 15.8442C24.73 15.8442 25.2128 16.3219 25.2128 16.7966C25.2128 17.278 24.73 17.7498 24.0079 17.7498Z" fill="currentColor"></path></svg><div class="wechat-dropdown"><p class="text-[#4c576c] text-xs">Connect on WeChat</p><img src="https://cdnd.selectdb.com/assets/images/doris-wechat-b949e908a3bc2776d824f79a9100bd4b.png" alt=""></div></a></div></div></div></div><div class="footer__copyright">Copyright © 2024 The Apache Software Foundation,Licensed under the <a href="https://www.apache.org/licenses/LICENSE-2.0" target="_blank">Apache License, Version 2.0</a>. Apache, Doris, Apache Doris, the Apache feather logo and the Apache Doris logo are trademarks of The Apache Software Foundation.</div></div></div></div> |
| <script src="https://cdnd.selectdb.com/assets/js/runtime~main.eb208fba.js"></script> |
| <script src="https://cdnd.selectdb.com/assets/js/main.fa7fcb85.js"></script> |
| </body> |
| </html> |
