blob: 861a7abc1b28deaa6fdae0bc75a04acb47f908a2 [file] [log] [blame]
<!doctype html>
<html lang="en" dir="ltr" class="docs-wrapper docs-doc-page docs-version-current plugin-docs plugin-id-default docs-doc-id-configuration/logging">
<head>
<meta charset="UTF-8">
<meta name="generator" content="Docusaurus v2.4.1">
<title data-rh="true">Logging | Apache® Druid</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:image" content="https://druid.apache.org/img/druid_nav.png"><meta data-rh="true" name="twitter:image" content="https://druid.apache.org/img/druid_nav.png"><meta data-rh="true" property="og:url" content="https://druid.apache.org/docs/latest/configuration/logging"><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-default-current"><meta data-rh="true" name="docsearch:version" content="current"><meta data-rh="true" name="docsearch:docusaurus_tag" content="docs-default-current"><meta data-rh="true" property="og:title" content="Logging | Apache® Druid"><meta data-rh="true" name="description" content="&lt;!--"><meta data-rh="true" property="og:description" content="&lt;!--"><link data-rh="true" rel="icon" href="/img/favicon.png"><link data-rh="true" rel="canonical" href="https://druid.apache.org/docs/latest/configuration/logging"><link data-rh="true" rel="alternate" href="https://druid.apache.org/docs/latest/configuration/logging" hreflang="en"><link data-rh="true" rel="alternate" href="https://druid.apache.org/docs/latest/configuration/logging" hreflang="x-default"><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=UA-131010415-1"></script>
<script>function gtag(){dataLayer.push(arguments)}window.dataLayer=window.dataLayer||[],gtag("js",new Date),gtag("config","UA-131010415-1",{})</script>
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.4/clipboard.min.js"></script><link rel="stylesheet" href="/assets/css/styles.546f39eb.css">
<link rel="preload" href="/assets/js/runtime~main.4c9a7172.js" as="script">
<link rel="preload" href="/assets/js/main.3a5ab01b.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")}()</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><nav aria-label="Main" class="navbar navbar--fixed-top navbar--dark"><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/druid_nav.png" alt="Apache® Druid" class="themedImage_ToTc themedImage--light_HNdA"><img src="/img/druid_nav.png" alt="Apache® Druid" class="themedImage_ToTc themedImage--dark_i4oU"></div></a></div><div class="navbar__items navbar__items--right"><a class="navbar__item navbar__link" href="/technology">Technology</a><a class="navbar__item navbar__link" href="/use-cases">Use Cases</a><a class="navbar__item navbar__link" href="/druid-powered">Powered By</a><a class="navbar__item navbar__link" href="/docs/latest/design/">Docs</a><a class="navbar__item navbar__link" href="/community/">Community</a><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href="#" aria-haspopup="true" aria-expanded="false" role="button" class="navbar__link">Apache®</a><ul class="dropdown__menu"><li><a href="https://www.apache.org/" target="_blank" rel="noopener noreferrer" class="dropdown__link">Foundation<svg width="12" height="12" 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><a href="https://apachecon.com/?ref=druid.apache.org" target="_blank" rel="noopener noreferrer" class="dropdown__link">Events<svg width="12" height="12" 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><a href="https://www.apache.org/licenses/" target="_blank" rel="noopener noreferrer" class="dropdown__link">License<svg width="12" height="12" 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><a href="https://www.apache.org/foundation/thanks.html" target="_blank" rel="noopener noreferrer" class="dropdown__link">Thanks<svg width="12" height="12" 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><a href="https://www.apache.org/security/" target="_blank" rel="noopener noreferrer" class="dropdown__link">Security<svg width="12" height="12" 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><a href="https://www.apache.org/foundation/sponsorship.html" target="_blank" rel="noopener noreferrer" class="dropdown__link">Sponsorship<svg width="12" height="12" 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><a class="navbar__item navbar__link" href="/downloads/">Download</a><div class="searchBox_ZlJk"><div class="navbar__search"><span aria-label="expand searchbar" role="button" class="search-icon" tabindex="0"></span><input type="search" id="search_input_react" placeholder="Loading..." aria-label="Search" class="navbar__search-input search-bar" disabled=""></div></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 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/latest/design/">Getting started</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/latest/tutorials/tutorial-msq-extern">Tutorials</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/latest/design/architecture">Design</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/latest/ingestion/">Ingestion</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/latest/data-management/">Data management</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/latest/querying/sql">Querying</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/latest/api-reference/">API reference</a></div></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 class="menu__link menu__link--sublist menu__link--sublist-caret menu__link--active" aria-expanded="true" href="/docs/latest/configuration/">Configuration</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/latest/configuration/">Configuration reference</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/latest/configuration/extensions">Extensions</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/latest/configuration/logging">Logging</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/latest/operations/web-console">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/latest/development/overview">Development</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/latest/misc/papers-and-talks">Misc</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">Configuration</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">Logging</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>Logging</h1></header><p>Apache Druid services emit logs that to help you debug.
The same services also emit periodic <a href="/docs/latest/configuration/#enabling-metrics">metrics</a> about their state.
To disable metric info logs set the following runtime property: <code>-Ddruid.emitter.logging.logLevel=debug</code>.</p><p>Druid uses <a href="http://logging.apache.org/log4j/2.x/" target="_blank" rel="noopener noreferrer">log4j2</a> for logging.
The default configuration file log4j2.xml ships with Druid at the following path: <code>conf/druid/{config}/_common/log4j2.xml</code>.</p><p>By default, Druid uses <code>RollingRandomAccessFile</code> for rollover daily, and keeps log files up to 7 days.
If that&#x27;s not suitable in your case, modify the <code>log4j2.xml</code> accordingly.</p><p>The following example log4j2.xml is based upon the micro quickstart:</p><div class="codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-text codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; ?&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;Configuration status=&quot;WARN&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Properties&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- to change log directory, set DRUID_LOG_DIR environment variable to your directory before launching Druid --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Property name=&quot;druid.log.path&quot; value=&quot;log&quot; /&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Properties&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appenders&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Console name=&quot;Console&quot; target=&quot;SYSTEM_OUT&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;PatternLayout pattern=&quot;%d{ISO8601} %p [%t] %c -%notEmpty{ [%markerSimpleName]} %m%n&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Console&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Rolling Files--&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;RollingRandomAccessFile name=&quot;FileAppender&quot;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> fileName=&quot;${sys:druid.log.path}/${sys:druid.node.type}.log&quot;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> filePattern=&quot;${sys:druid.log.path}/${sys:druid.node.type}.%d{yyyyMMdd}.log&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;PatternLayout pattern=&quot;%d{ISO8601} %p [%t] %c -%notEmpty{ [%markerSimpleName]} %m%n&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Policies&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;TimeBasedTriggeringPolicy interval=&quot;1&quot; modulate=&quot;true&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Policies&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;DefaultRolloverStrategy&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Delete basePath=&quot;${sys:druid.log.path}/&quot; maxDepth=&quot;1&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;IfFileName glob=&quot;*.log&quot; /&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;IfLastModified age=&quot;7d&quot; /&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Delete&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/DefaultRolloverStrategy&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/RollingRandomAccessFile&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Appenders&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Loggers&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Root level=&quot;info&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Root&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Set level=&quot;debug&quot; to see stack traces for query errors --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.apache.druid.server.QueryResource&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.apache.druid.server.QueryLifecycle&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Set level=&quot;debug&quot; or &quot;trace&quot; to see more Coordinator details (segment balancing, load/drop rules, etc) --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.apache.druid.server.coordinator&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Set level=&quot;debug&quot; to see low-level details about segments and ingestion --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.apache.druid.segment&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Set level=&quot;debug&quot; to see more information about extension initialization --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.apache.druid.initialization&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Quieter logging at startup --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;org.skife.config&quot; level=&quot;warn&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Logger name=&quot;com.sun.jersey.guice&quot; level=&quot;warn&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appender-ref ref=&quot;FileAppender&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Logger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Loggers&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;/Configuration&gt;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>Peons always output logs to standard output. Middle Managers redirect task logs from standard output to
<a href="/docs/latest/configuration/#log-long-term-storage">long-term storage</a>.</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> NOTE:
Druid shares the log4j configuration file among all services, including task peon processes.
However, you must define a console appender in the logger for your peon processes.
If you don&#x27;t define a console appender, Druid creates and configures a new console appender
that retains the log level, such as <code>info</code> or <code>warn</code>, but does not retain any other appender
configuration, including non-console ones.</p></div></div><h2 class="anchor anchorWithStickyNavbar_LWe7" id="log-directory">Log directory<a href="#log-directory" class="hash-link" aria-label="Direct link to Log directory" title="Direct link to Log directory"></a></h2><p>The included log4j2.xml configuration for Druid and ZooKeeper writes logs to the <code>log</code> directory at the root of the distribution.</p><p>If you want to change the log directory, set the environment variable <code>DRUID_LOG_DIR</code> to the right directory before you start Druid.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="all-in-one-start-commands">All-in-one start commands<a href="#all-in-one-start-commands" class="hash-link" aria-label="Direct link to All-in-one start commands" title="Direct link to All-in-one start commands"></a></h2><p>If you use one of the all-in-one start commands, such as <code>bin/start-micro-quickstart</code>, the default configuration for each service has two kinds of log files.
Log4j2 writes the main log file and rotates it periodically.
For example, <code>log/historical.log</code>.</p><p>The secondary log file contains anything that is written by the component
directly to standard output or standard error without going through log4j2.
For example, <code>log/historical.stdout.log</code>.
This consists mainly of messages from the
Java runtime itself.
This file is not rotated, but it is generally small due to the low volume of messages.
If necessary, you can truncate it using the Linux command <code>truncate --size 0 log/historical.stdout.log</code>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="set-the-logs-to-asynchronously-write">Set the logs to asynchronously write<a href="#set-the-logs-to-asynchronously-write" class="hash-link" aria-label="Direct link to Set the logs to asynchronously write" title="Direct link to Set the logs to asynchronously write"></a></h2><p>If your logs are really chatty, you can set them to write asynchronously.
The following example shows a <code>log4j2.xml</code> that configures some of the more chatty classes to write asynchronously:</p><div class="codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-text codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; ?&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;Configuration status=&quot;WARN&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Appenders&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Console name=&quot;Console&quot; target=&quot;SYSTEM_OUT&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;PatternLayout pattern=&quot;%d{ISO8601} %p [%t] %c -%notEmpty{ [%markerSimpleName]} %m%n&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Console&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Appenders&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> </span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;Loggers&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- AsyncLogger instead of Logger --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AsyncLogger name=&quot;org.apache.druid.curator.inventory.CuratorInventoryManager&quot; level=&quot;debug&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;Console&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/AsyncLogger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AsyncLogger name=&quot;org.apache.druid.client.BatchServerInventoryView&quot; level=&quot;debug&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;Console&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/AsyncLogger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;!-- Make extra sure nobody adds logs in a bad way that can hurt performance --&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AsyncLogger name=&quot;org.apache.druid.client.ServerInventoryView&quot; level=&quot;debug&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;Console&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/AsyncLogger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AsyncLogger name =&quot;org.apache.druid.java.util.http.client.pool.ChannelResourceFactory&quot; level=&quot;info&quot; additivity=&quot;false&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;Console&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/AsyncLogger&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;Root level=&quot;info&quot;&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;AppenderRef ref=&quot;Console&quot;/&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Root&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> &lt;/Loggers&gt;</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">&lt;/Configuration&gt;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div></div></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href="/docs/latest/configuration/extensions"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">Extensions</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/docs/latest/operations/web-console"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">Web console</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="#log-directory" class="table-of-contents__link toc-highlight">Log directory</a></li><li><a href="#all-in-one-start-commands" class="table-of-contents__link toc-highlight">All-in-one start commands</a></li><li><a href="#set-the-logs-to-asynchronously-write" class="table-of-contents__link toc-highlight">Set the logs to asynchronously write</a></li></ul></div></div></div></div></main></div></div><footer class="footer"><div class="container container-fluid"><div class="footer__bottom text--center"><div class="margin-bottom--sm"><img src="/img/favicon.png" class="themedImage_ToTc themedImage--light_HNdA footer__logo"><img src="/img/favicon.png" class="themedImage_ToTc themedImage--dark_i4oU footer__logo"></div><div class="footer__copyright">Copyright © 2023 Apache Software Foundation. Except where otherwise noted, licensed under CC BY-SA 4.0. Apache Druid, Druid, and the Druid logo are either registered trademarks or trademarks of The Apache Software Foundation in the United States and other countries.</div></div></div></footer></div>
<script src="/assets/js/runtime~main.4c9a7172.js"></script>
<script src="/assets/js/main.3a5ab01b.js"></script>
</body>
</html>