blob: 18cecde34301abec4f1b19a48b50e4ba0205f1b8 [file] [log] [blame]
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="Apache Druid">
<meta name="keywords" content="druid,kafka,database,analytics,streaming,real-time,real time,apache,open source">
<meta name="author" content="Apache Software Foundation">
<title>Druid | Overlord Node</title>
<link rel="alternate" type="application/atom+xml" href="/feed">
<link rel="shortcut icon" href="/img/favicon.png">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">
<link href='//fonts.googleapis.com/css?family=Open+Sans+Condensed:300,700,300italic|Open+Sans:300italic,400italic,600italic,400,300,600,700' rel='stylesheet' type='text/css'>
<link rel="stylesheet" href="/css/bootstrap-pure.css?v=1.1">
<link rel="stylesheet" href="/css/base.css?v=1.1">
<link rel="stylesheet" href="/css/header.css?v=1.1">
<link rel="stylesheet" href="/css/footer.css?v=1.1">
<link rel="stylesheet" href="/css/syntax.css?v=1.1">
<link rel="stylesheet" href="/css/docs.css?v=1.1">
<script>
(function() {
var cx = '000162378814775985090:molvbm0vggm';
var gcse = document.createElement('script');
gcse.type = 'text/javascript';
gcse.async = true;
gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') +
'//cse.google.com/cse.js?cx=' + cx;
var s = document.getElementsByTagName('script')[0];
s.parentNode.insertBefore(gcse, s);
})();
</script>
</head>
<body>
<!-- Start page_header include -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div class="top-navigator">
<div class="container">
<div class="left-cont">
<a class="logo" href="/"><span class="druid-logo"></span></a>
</div>
<div class="right-cont">
<ul class="links">
<li class=""><a href="/technology">Technology</a></li>
<li class=""><a href="/use-cases">Use Cases</a></li>
<li class=""><a href="/druid-powered">Powered By</a></li>
<li class=""><a href="/docs/latest/design/">Docs</a></li>
<li class=""><a href="/community/">Community</a></li>
<li class="header-dropdown">
<a>Apache</a>
<div class="header-dropdown-menu">
<a href="https://www.apache.org/" target="_blank">Foundation</a>
<a href="https://www.apache.org/events/current-event" target="_blank">Events</a>
<a href="https://www.apache.org/licenses/" target="_blank">License</a>
<a href="https://www.apache.org/foundation/thanks.html" target="_blank">Thanks</a>
<a href="https://www.apache.org/security/" target="_blank">Security</a>
<a href="https://www.apache.org/foundation/sponsorship.html" target="_blank">Sponsorship</a>
</div>
</li>
<li class=" button-link"><a href="/downloads.html">Download</a></li>
</ul>
</div>
</div>
<div class="action-button menu-icon">
<span class="fa fa-bars"></span> MENU
</div>
<div class="action-button menu-icon-close">
<span class="fa fa-times"></span> MENU
</div>
</div>
<script type="text/javascript">
var $menu = $('.right-cont');
var $menuIcon = $('.menu-icon');
var $menuIconClose = $('.menu-icon-close');
function showMenu() {
$menu.fadeIn(100);
$menuIcon.fadeOut(100);
$menuIconClose.fadeIn(100);
}
$menuIcon.click(showMenu);
function hideMenu() {
$menu.fadeOut(100);
$menuIconClose.fadeOut(100);
$menuIcon.fadeIn(100);
}
$menuIconClose.click(hideMenu);
$(window).resize(function() {
if ($(window).width() >= 840) {
$menu.fadeIn(100);
$menuIcon.fadeOut(100);
$menuIconClose.fadeOut(100);
}
else {
$menu.fadeOut(100);
$menuIcon.fadeIn(100);
$menuIconClose.fadeOut(100);
}
});
</script>
<!-- Stop page_header include -->
<div class="container doc-container">
<p> Looking for the <a href="/docs/0.20.0/">latest stable documentation</a>?</p>
<div class="row">
<div class="col-md-9 doc-content">
<p>
<a class="btn btn-default btn-xs visible-xs-inline-block visible-sm-inline-block" href="#toc">Table of Contents</a>
</p>
<!--
~ Licensed to the Apache Software Foundation (ASF) under one
~ or more contributor license agreements. See the NOTICE file
~ distributed with this work for additional information
~ regarding copyright ownership. The ASF licenses this file
~ to you under the Apache License, Version 2.0 (the
~ "License"); you may not use this file except in compliance
~ with the License. You may obtain a copy of the License at
~
~ http://www.apache.org/licenses/LICENSE-2.0
~
~ Unless required by applicable law or agreed to in writing,
~ software distributed under the License is distributed on an
~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
~ KIND, either express or implied. See the License for the
~ specific language governing permissions and limitations
~ under the License.
-->
<h1 id="overlord-node">Overlord Node</h1>
<h3 id="configuration">Configuration</h3>
<p>For Overlord Node Configuration, see <a href="../configuration/index.html#overlord">Overlord Configuration</a>.</p>
<h3 id="http-endpoints">HTTP Endpoints</h3>
<p>For a list of API endpoints supported by the Overlord, please see the <a href="../operations/api-reference.html#overlord">API reference</a>.</p>
<h3 id="overview">Overview</h3>
<p>The overlord node is responsible for accepting tasks, coordinating task distribution, creating locks around tasks, and returning statuses to callers. Overlord can be configured to run in one of two modes - local or remote (local being default).
In local mode overlord is also responsible for creating peons for executing tasks. When running the overlord in local mode, all middle manager and peon configurations must be provided as well.
Local mode is typically used for simple workflows. In remote mode, the overlord and middle manager are run in separate processes and you can run each on a different server.
This mode is recommended if you intend to use the indexing service as the single endpoint for all Druid indexing.</p>
<h3 id="overlord-console">Overlord Console</h3>
<p>The overlord console can be used to view pending tasks, running tasks, available workers, and recent worker creation and termination. The console can be accessed at:</p>
<div class="highlight"><pre><code class="language-text" data-lang="text"><span></span>http://&lt;OVERLORD_IP&gt;:&lt;port&gt;/console.html
</code></pre></div>
<h3 id="blacklisted-workers">Blacklisted Workers</h3>
<p>If the workers fail tasks above a threshold, the overlord will blacklist these workers. No more than 20% of the nodes can be blacklisted. Blacklisted nodes will be periodically whitelisted.</p>
<p>The following vairables can be used to set the threshold and blacklist timeouts.</p>
<div class="highlight"><pre><code class="language-text" data-lang="text"><span></span>druid.indexer.runner.maxRetriesBeforeBlacklist
druid.indexer.runner.workerBlackListBackoffTime
druid.indexer.runner.workerBlackListCleanupPeriod
druid.indexer.runner.maxPercentageBlacklistWorkers
</code></pre></div>
<h3 id="autoscaling">Autoscaling</h3>
<p>The Autoscaling mechanisms currently in place are tightly coupled with our deployment infrastructure but the framework should be in place for other implementations. We are highly open to new implementations or extensions of the existing mechanisms. In our own deployments, middle manager nodes are Amazon AWS EC2 nodes and they are provisioned to register themselves in a <a href="https://github.com/ning/galaxy">galaxy</a> environment.</p>
<p>If autoscaling is enabled, new middle managers may be added when a task has been in pending state for too long. Middle managers may be terminated if they have not run any tasks for a period of time.</p>
</div>
<div class="col-md-3">
<div class="searchbox">
<gcse:searchbox-only></gcse:searchbox-only>
</div>
<div id="toc" class="nav toc hidden-print">
</div>
</div>
</div>
</div>
<!-- Start page_footer include -->
<footer class="druid-footer">
<div class="container">
<div class="text-center">
<p>
<a href="/technology">Technology</a>&ensp;·&ensp;
<a href="/use-cases">Use Cases</a>&ensp;·&ensp;
<a href="/druid-powered">Powered by Druid</a>&ensp;·&ensp;
<a href="/docs/latest/">Docs</a>&ensp;·&ensp;
<a href="/community/">Community</a>&ensp;·&ensp;
<a href="/downloads.html">Download</a>&ensp;·&ensp;
<a href="/faq">FAQ</a>
</p>
</div>
<div class="text-center">
<a title="Join the user group" href="https://groups.google.com/forum/#!forum/druid-user" target="_blank"><span class="fa fa-comments"></span></a>&ensp;·&ensp;
<a title="Follow Druid" href="https://twitter.com/druidio" target="_blank"><span class="fab fa-twitter"></span></a>&ensp;·&ensp;
<a title="GitHub" href="https://github.com/apache/druid" target="_blank"><span class="fab fa-github"></span></a>
</div>
<div class="text-center license">
Copyright © 2020 <a href="https://www.apache.org/" target="_blank">Apache Software Foundation</a>.<br>
Except where otherwise noted, licensed under <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0</a>.<br>
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>
</footer>
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-131010415-1"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'UA-131010415-1');
</script>
<script>
function trackDownload(type, url) {
ga('send', 'event', 'download', type, url);
}
</script>
<script src="//code.jquery.com/jquery.min.js"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="/assets/js/druid.js"></script>
<!-- stop page_footer include -->
<script>
$(function() {
$(".toc").load("/docs/0.13.0-incubating/toc.html");
// There is no way to tell when .gsc-input will be async loaded into the page so just try to set a placeholder until it works
var tries = 0;
var timer = setInterval(function() {
tries++;
if (tries > 300) clearInterval(timer);
var searchInput = $('input.gsc-input');
if (searchInput.length) {
searchInput.attr('placeholder', 'Search');
clearInterval(timer);
}
}, 100);
});
</script>
</body>
</html>