<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><title>Local Cluster · Apache Heron</title><meta name="viewport" content="width=device-width"/><meta name="generator" content="Docusaurus"/><meta name="description" content="&lt;!--"/><meta name="docsearch:version" content="0.20.0-incubating"/><meta name="docsearch:language" content="en"/><meta property="og:title" content="Local Cluster · Apache Heron"/><meta property="og:type" content="website"/><meta property="og:url" content="https://heron.apache.org/"/><meta property="og:description" content="&lt;!--"/><meta property="og:image" content="https://heron.apache.org/img/undraw_online.svg"/><meta name="twitter:card" content="summary"/><meta name="twitter:image" content="https://heron.apache.org/img/undraw_tweetstorm.svg"/><link rel="shortcut icon" href="/img/favicon-32x32.png"/><link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/default.min.css"/><link rel="alternate" type="application/atom+xml" href="https://heron.apache.org/blog/atom.xml" title="Apache Heron Blog ATOM Feed"/><link rel="alternate" type="application/rss+xml" href="https://heron.apache.org/blog/feed.xml" title="Apache Heron Blog RSS Feed"/><script>
              (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
              (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
              m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
              })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

              ga('create', 'UA-198017384-1', 'auto');
              ga('send', 'pageview');
            </script><script type="text/javascript" src="https://buttons.github.io/buttons.js"></script><script type="text/javascript" src="/js/custom.js"></script><script type="text/javascript" src="/js/fix-location.js"></script><link rel="stylesheet" href="/css/main.css"/><script src="/js/codetabs.js"></script></head><body class="sideNavVisible separateOnPageNav"><div class="fixedHeaderContainer"><div class="headerWrapper wrapper"><header><a href="/"><img class="logo" src="/img/HeronTextLogo-small.png" alt="Apache Heron"/><h2 class="headerTitleWithLogo">Apache Heron</h2></a><a href="/versions"><h3>0.20.0-incubating</h3></a><div class="navigationWrapper navigationSlider"><nav class="slidingNav"><ul class="nav-site nav-site-internal"><li class=""><a href="/api/java" target="_self">Javadocs</a></li><li class=""><a href="/api/python" target="_self">Pydocs</a></li><li class="siteNavGroupActive"><a href="/docs/0.20.0-incubating/getting-started-local-single-node" target="_self">Docs</a></li><li class=""><a href="/download" target="_self">Downloads</a></li><li class=""><a href="#community" target="_self">Community</a></li><li class=""><a href="/blog/" target="_self">Blog</a></li><li class=""><a href="#apache" target="_self">Apache</a></li></ul></nav></div></header></div></div><div class="navPusher"><div class="docMainWrapper wrapper"><div class="container docsNavContainer" id="docsNav"><nav class="toc"><div class="toggleNav"><section class="navWrapper wrapper"><div class="navBreadcrumb wrapper"><div class="navToggle" id="navToggler"><div class="hamburger-menu"><div class="line1"></div><div class="line2"></div><div class="line3"></div></div></div><h2><i>›</i><span>Schedulers</span></h2><div class="tocToggler" id="tocToggler"><i class="icon-toc"></i></div></div><div class="navGroups"><div class="navGroup"><h3 class="navGroupCategoryTitle">Getting Started</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/getting-started-local-single-node">Local (Single Node)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/getting-started-migrate-storm-topologies">Migrate Storm Topologies</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/getting-started-troubleshooting-guide">Troubleshooting Guide</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Deployment</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/deployment-overview">Deployment Overiew</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/deployment-configuration">Configuration</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/deployment-api-server">The Heron API Server</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Topology Development APIs</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/topology-development-streamlet-api">The Heron Streamlet API for Java</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/topology-development-eco-api">The ECO API for Java</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/topology-development-topology-api-java">The Heron Topology API for Java</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/topology-development-topology-api-python">The Heron Topology API for Python</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/topology-development-streamlet-scala">The Heron Streamlet API for Scala</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Client API Docs</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/client-api-docs-overview">Client API Docs</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Guides</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-effectively-once-java-topologies">Effectively Once Java Topologies</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-data-model">Heron Data Model</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-tuple-serialization">Tuple Serialization</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-ui-guide">Heron UI Guide</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-topology-tuning">Topology Tuning Guide</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-packing-algorithms">Packing Algorithms</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-simulator-mode">Simulator Mode</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/guides-troubeshooting-guide">Topology Troubleshooting Guide</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Heron Concepts</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-design-goals">Heron Design Goals</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-topology-concepts">Heron Topologies</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-streamlet-concepts">Heron Streamlets</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-architecture">Heron Architecture</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-delivery-semantics">Heron Delivery Semantics</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">State Managers</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/state-managers-zookeeper">Zookeeper</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/state-managers-local-fs">Local File System</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Uploaders</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/uploaders-local-fs">Local File System</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/uploaders-hdfs">HDFS</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/uploaders-http">HTTP</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/uploaders-amazon-s3">Amazon S3</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/uploaders-scp">Secure Copy (SCP)</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Schedulers</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-k8s-by-hand">Kubernetes by hand</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-k8s-with-helm">Kubernetes with Helm</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-aurora-cluster">Aurora Cluster</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-aurora-local">Aurora Locally</a></li><li class="navListItem navListItemActive"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-local">Local Cluster</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-nomad">Nomad</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-mesos-local-mac">Mesos Cluster Locally</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-slurm">Slurm Cluster</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/schedulers-yarn">YARN Cluster</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Cluster Configuration</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-overview">Cluster Config Overview</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-system-level">System Level Configuration</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-instance">Heron Instance</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-metrics">Metrics Manager</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-stream">Stream Manager</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/cluster-config-tmanager">Topology Manager</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Observability</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/observability-prometheus">Prometheus</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/observability-graphite">Graphite</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/observability-scribe">Scribe</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">User Manuals</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-heron-cli">Heron Client</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-heron-explorer">Heron Explorer</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-tracker-rest">Heron Tracker REST API</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-heron-tracker-runbook">Heron Tracker Runbook</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-heron-ui-runbook">Heron UI Runbook</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/user-manuals-heron-shell">Heron Shell</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Compiling</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-overview">Compiling Overview</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-linux">Compiling on Linux</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-osx">Compiling on OS X</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-docker">Compiling With Docker</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-running-tests">Running Tests</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/compiling-code-organization">Code Organization</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Extending Heron</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/extending-heron-scheduler">Custom Scheduler</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/extending-heron-metric-sink">Custom Metrics Sink</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle">Heron Resources</h3><ul class=""><li class="navListItem"><a class="navItem" href="/docs/0.20.0-incubating/heron-resources-resources">Heron Resources</a></li></ul></div></div></section></div><script>
            var coll = document.getElementsByClassName('collapsible');
            var checkActiveCategory = true;
            for (var i = 0; i < coll.length; i++) {
              var links = coll[i].nextElementSibling.getElementsByTagName('*');
              if (checkActiveCategory){
                for (var j = 0; j < links.length; j++) {
                  if (links[j].classList.contains('navListItemActive')){
                    coll[i].nextElementSibling.classList.toggle('hide');
                    coll[i].childNodes[1].classList.toggle('rotate');
                    checkActiveCategory = false;
                    break;
                  }
                }
              }

              coll[i].addEventListener('click', function() {
                var arrow = this.childNodes[1];
                arrow.classList.toggle('rotate');
                var content = this.nextElementSibling;
                content.classList.toggle('hide');
              });
            }

            document.addEventListener('DOMContentLoaded', function() {
              createToggler('#navToggler', '#docsNav', 'docsSliderActive');
              createToggler('#tocToggler', 'body', 'tocActive');

              var headings = document.querySelector('.toc-headings');
              headings && headings.addEventListener('click', function(event) {
                var el = event.target;
                while(el !== headings){
                  if (el.tagName === 'A') {
                    document.body.classList.remove('tocActive');
                    break;
                  } else{
                    el = el.parentNode;
                  }
                }
              }, false);

              function createToggler(togglerSelector, targetSelector, className) {
                var toggler = document.querySelector(togglerSelector);
                var target = document.querySelector(targetSelector);

                if (!toggler) {
                  return;
                }

                toggler.onclick = function(event) {
                  event.preventDefault();

                  target.classList.toggle(className);
                };
              }
            });
        </script></nav></div><div class="container mainContainer"><div class="wrapper"><div class="post"><header class="postHeader"><h1 class="postHeaderTitle">Local Cluster</h1></header><article><div><span><!--
    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.
-->
<p>In addition to out-of-the-box schedulers for
<a href="schedulers-aurora-cluster">Aurora</a>, Heron can also be deployed in a local environment, which
stands up a mock Heron cluster on a single machine. This can be useful for
experimenting with Heron's features, testing a wide variety of possible cluster
events, and so on.</p>
<p>One of two state managers can be used for coordination when deploying locally:</p>
<ul>
<li><a href="state-managers-zookeeper">ZooKeeper</a></li>
<li><a href="state-managers-local-fs">Local File System</a></li>
</ul>
<p><strong>Note</strong>: Deploying a Heron cluster locally is not to be confused with Heron's
<a href="guides-simulator-mode">simulator mode</a>. Simulator mode enables
you to run topologies in a cluster-agnostic JVM process for the purpose of
development and debugging, while the local scheduler stands up a Heron cluster
on a single machine.</p>
<h2><a class="anchor" aria-hidden="true" id="how-local-deployment-works"></a><a href="#how-local-deployment-works" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>How Local Deployment Works</h2>
<p>Using the local scheduler is similar to deploying Heron on other schedulers.
The <a href="user-manuals-heron-cli">Heron</a> cli is used to deploy and manage topologies
as would be done using a distributed scheduler. The main difference is in
the configuration.</p>
<h2><a class="anchor" aria-hidden="true" id="local-scheduler-configuration"></a><a href="#local-scheduler-configuration" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Local Scheduler Configuration</h2>
<p>To configure Heron to use local scheduler, specify the following in <code>scheduler.yaml</code>
config file.</p>
<ul>
<li><p><code>heron.class.scheduler</code> --- Indicates the class to be loaded for local scheduler.
Set this to <code>org.apache.heron.scheduler.local.LocalScheduler</code></p></li>
<li><p><code>heron.class.launcher</code> --- Specifies the class to be loaded for launching
topologies. Set this to <code>org.apache.heron.scheduler.local.LocalLauncher</code></p></li>
<li><p><code>heron.scheduler.local.working.directory</code> --- Provides the working
directory for topology. The working directory is essentially a scratch pad where
topology jars, heron core release binaries, topology logs, etc are generated and kept.</p></li>
<li><p><code>heron.package.core.uri</code> --- Indicates the location of the heron core binary package.
The local scheduler uses this URI to download the core package to the working directory.</p></li>
<li><p><code>heron.directory.sandbox.java.home</code> --- Specifies the java home to
be used when running topologies in the containers. Set to <code>${JAVA_HOME}</code> to
use the value set in the bash environment variable $JAVA_HOME.</p></li>
</ul>
<h3><a class="anchor" aria-hidden="true" id="example-local-scheduler-configuration"></a><a href="#example-local-scheduler-configuration" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Example Local Scheduler Configuration</h3>
<pre><code class="hljs css language-yaml"><span class="hljs-comment"># scheduler class for distributing the topology for execution</span>
<span class="hljs-attr">heron.class.scheduler:</span> <span class="hljs-string">org.apache.heron.scheduler.local.LocalScheduler</span>

<span class="hljs-comment"># launcher class for submitting and launching the topology</span>
<span class="hljs-attr">heron.class.launcher:</span> <span class="hljs-string">org.apache.heron.scheduler.local.LocalLauncher</span>

<span class="hljs-comment"># working directory for the topologies</span>
<span class="hljs-attr">heron.scheduler.local.working.directory:</span> <span class="hljs-string">${HOME}/.herondata/topologies/${CLUSTER}/${TOPOLOGY}</span>

<span class="hljs-comment"># location of the core package</span>
<span class="hljs-attr">heron.package.core.uri:</span> <span class="hljs-string">file://${HERON_DIST}/heron-core.tar.gz</span>

<span class="hljs-comment"># location of java - pick it up from shell environment</span>
<span class="hljs-attr">heron.directory.sandbox.java.home:</span> <span class="hljs-string">${JAVA_HOME}</span>
</code></pre>
</span></div></article></div><div class="docs-prevnext"><a class="docs-prev button" href="/docs/0.20.0-incubating/schedulers-aurora-local"><span class="arrow-prev">← </span><span>Aurora Locally</span></a><a class="docs-next button" href="/docs/0.20.0-incubating/schedulers-standalone"><span>Next</span><span class="arrow-next"> →</span></a></div></div></div><nav class="onPageNav"><ul class="toc-headings"><li><a href="#how-local-deployment-works">How Local Deployment Works</a></li><li><a href="#local-scheduler-configuration">Local Scheduler Configuration</a><ul class="toc-headings"><li><a href="#example-local-scheduler-configuration">Example Local Scheduler Configuration</a></li></ul></li></ul></nav></div><footer class="nav-footer" id="footer"><div class="apache-disclaimer">Apache Heron is an effort undergoing incubation at <a target="_blank" href="https://apache.org/">The Apache Software Foundation (ASF)</a> sponsored by the Apache Incubator PMC. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.<br/><br/>Apache®, the names of Apache projects, and the feather logo are either <a rel="external" href="https://www.apache.org/foundation/marks/list/">registered trademarks or trademarks</a> of the Apache Software Foundation in the United States and/or other countries.<br/><br/><div class="copyright-box">Copyright © 2023 the Apache Software Foundation, Apache Heron, Heron, 
  Apache, the Apache feather Logo, and the Apache Heron project logo are either registered 
  trademarks or trademarks of the Apache Software Foundation.</div></div><div class="apache-links"><a class="item" rel="external" href="https://incubator.apache.org/">Apache Incubator</a><div><a class="item" rel="external" href="https://www.apache.org/">About the ASF</a></div><div><a class="item" rel="external" href="https://www.apache.org/events/current-event">Events</a></div><div><a class="item" rel="external" href="https://www.apache.org/foundation/thanks.html">Thanks</a></div><div><a class="item" rel="external" href="https://www.apache.org/foundation/sponsorship.html">Become a Sponsor</a></div><div><a class="item" rel="external" href="https://www.apache.org/security/">Security</a></div><div><a class="item" rel="external" href="https://www.apache.org/licenses/">License</a></div></div></footer></div><script>window.twttr=(function(d,s, id){var js,fjs=d.getElementsByTagName(s)[0],t=window.twttr||{};if(d.getElementById(id))return t;js=d.createElement(s);js.id=id;js.src='https://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js, fjs);t._e = [];t.ready = function(f) {t._e.push(f);};return t;}(document, 'script', 'twitter-wjs'));</script></body></html>