content/docs/r3.3.1/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/apidocs/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html - hadoop-site - Git at Google

 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <!-- NewPage -->
 <html lang="en">
 <head>
 <!-- Generated by javadoc (1.8.0_292) on Tue Jun 15 06:11:53 GMT 2021 -->
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>TimelineReader (Apache Hadoop YARN Timeline Service 3.3.1 API)</title>
 <meta name="date" content="2021-06-15">
 <link rel="stylesheet" type="text/css" href="../../../../../../../stylesheet.css" title="Style">
 <script type="text/javascript" src="../../../../../../../script.js"></script>
 </head>
 <body>
 <script type="text/javascript"><!--
     try {
         if (location.href.indexOf('is-external=true') == -1) {
             parent.document.title="TimelineReader (Apache Hadoop YARN Timeline Service 3.3.1 API)";
         }
     }
     catch(err) {
     }
 //-->
 var methods = {"i0":6,"i1":6,"i2":6,"i3":6};
 var tabs = {65535:["t0","All Methods"],2:["t2","Instance Methods"],4:["t3","Abstract Methods"]};
 var altColor = "altColor";
 var rowColor = "rowColor";
 var tableTab = "tableTab";
 var activeTableTab = "activeTableTab";
 </script>
 <noscript>
 <div>JavaScript is disabled on your browser.</div>
 </noscript>
 <!-- ========= START OF TOP NAVBAR ======= -->
 <div class="topNav"><a name="navbar.top">
 <!--   -->
 </a>
 <div class="skipNav"><a href="#skip.navbar.top" title="Skip navigation links">Skip navigation links</a></div>
 <a name="navbar.top.firstrow">
 <!--   -->
 </a>
 <ul class="navList" title="Navigation">
 <li><a href="../../../../../../../overview-summary.html">Overview</a></li>
 <li><a href="package-summary.html">Package</a></li>
 <li class="navBarCell1Rev">Class</li>
 <li><a href="class-use/TimelineReader.html">Use</a></li>
 <li><a href="package-tree.html">Tree</a></li>
 <li><a href="../../../../../../../deprecated-list.html">Deprecated</a></li>
 <li><a href="../../../../../../../index-all.html">Index</a></li>
 <li><a href="../../../../../../../help-doc.html">Help</a></li>
 </ul>
 </div>
 <div class="subNav">
 <ul class="navList">
 <li><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineAggregationTrack.html" title="enum in org.apache.hadoop.yarn.server.timelineservice.storage"><span class="typeNameLink">Prev&nbsp;Class</span></a></li>
 <li><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.Field.html" title="enum in org.apache.hadoop.yarn.server.timelineservice.storage"><span class="typeNameLink">Next&nbsp;Class</span></a></li>
 </ul>
 <ul class="navList">
 <li><a href="../../../../../../../index.html?org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html" target="_top">Frames</a></li>
 <li><a href="TimelineReader.html" target="_top">No&nbsp;Frames</a></li>
 </ul>
 <ul class="navList" id="allclasses_navbar_top">
 <li><a href="../../../../../../../allclasses-noframe.html">All&nbsp;Classes</a></li>
 </ul>
 <div>
 <script type="text/javascript"><!--
   allClassesLink = document.getElementById("allclasses_navbar_top");
   if(window==top) {
     allClassesLink.style.display = "block";
   }
   else {
     allClassesLink.style.display = "none";
   }
   //-->
 </script>
 </div>
 <div>
 <ul class="subNavList">
 <li>Summary:&nbsp;</li>
 <li><a href="#nested.class.summary">Nested</a>&nbsp;|&nbsp;</li>
 <li>Field&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method.summary">Method</a></li>
 </ul>
 <ul class="subNavList">
 <li>Detail:&nbsp;</li>
 <li>Field&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method.detail">Method</a></li>
 </ul>
 </div>
 <a name="skip.navbar.top">
 <!--   -->
 </a></div>
 <!-- ========= END OF TOP NAVBAR ========= -->
 <!-- ======== START OF CLASS DATA ======== -->
 <div class="header">
 <div class="subTitle">org.apache.hadoop.yarn.server.timelineservice.storage</div>
 <h2 title="Interface TimelineReader" class="title">Interface TimelineReader</h2>
 </div>
 <div class="contentContainer">
 <div class="description">
 <ul class="blockList">
 <li class="blockList">
 <dl>
 <dt>All Superinterfaces:</dt>
 <dd><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/AutoCloseable.html?is-external=true" title="class or interface in java.lang">AutoCloseable</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/io/Closeable.html?is-external=true" title="class or interface in java.io">Closeable</a>, org.apache.hadoop.service.Service</dd>
 </dl>
 <dl>
 <dt>All Known Implementing Classes:</dt>
 <dd><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/FileSystemTimelineReaderImpl.html" title="class in org.apache.hadoop.yarn.server.timelineservice.storage">FileSystemTimelineReaderImpl</a>, <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/NoOpTimelineReaderImpl.html" title="class in org.apache.hadoop.yarn.server.timelineservice.storage">NoOpTimelineReaderImpl</a></dd>
 </dl>
 <hr>
 <br>
 <pre>@InterfaceAudience.Private
  @InterfaceStability.Unstable
 public interface <span class="typeNameLabel">TimelineReader</span>
 extends org.apache.hadoop.service.Service</pre>
 <div class="block">ATSv2 reader interface.</div>
 </li>
 </ul>
 </div>
 <div class="summary">
 <ul class="blockList">
 <li class="blockList">
 <!-- ======== NESTED CLASS SUMMARY ======== -->
 <ul class="blockList">
 <li class="blockList"><a name="nested.class.summary">
 <!--   -->
 </a>
 <h3>Nested Class Summary</h3>
 <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Nested Class Summary table, listing nested classes, and an explanation">
 <caption><span>Nested Classes</span><span class="tabEnd">&nbsp;</span></caption>
 <tr>
 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colLast" scope="col">Interface and Description</th>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>static class&nbsp;</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.Field.html" title="enum in org.apache.hadoop.yarn.server.timelineservice.storage">TimelineReader.Field</a></span></code>
 <div class="block">Possible fields to retrieve for <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getEntities-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-"><code>getEntities(org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext, org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters, org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve)</code></a> and
  <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getEntity-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-"><code>getEntity(org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext, org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve)</code></a>.</div>
 </td>
 </tr>
 </table>
 <ul class="blockList">
 <li class="blockList"><a name="nested.classes.inherited.from.class.org.apache.hadoop.service.Service">
 <!--   -->
 </a>
 <h3>Nested classes/interfaces inherited from interface&nbsp;org.apache.hadoop.service.Service</h3>
 <code>org.apache.hadoop.service.Service.STATE</code></li>
 </ul>
 </li>
 </ul>
 <!-- ========== METHOD SUMMARY =========== -->
 <ul class="blockList">
 <li class="blockList"><a name="method.summary">
 <!--   -->
 </a>
 <h3>Method Summary</h3>
 <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation">
 <caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd">&nbsp;</span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd">&nbsp;</span></span><span id="t3" class="tableTab"><span><a href="javascript:show(4);">Abstract Methods</a></span><span class="tabEnd">&nbsp;</span></span></caption>
 <tr>
 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colLast" scope="col">Method and Description</th>
 </tr>
 <tr id="i0" class="altColor">
 <td class="colFirst"><code><a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity&gt;</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getEntities-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-">getEntities</a></span>(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context,
            <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineEntityFilters.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineEntityFilters</a>&nbsp;filters,
            <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineDataToRetrieve</a>&nbsp;dataToRetrieve)</code>
 <div class="block">The API to search for a set of entities of the given entity type in
  the scope of the given context which matches the given predicates.</div>
 </td>
 </tr>
 <tr id="i1" class="rowColor">
 <td class="colFirst"><code>org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getEntity-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-">getEntity</a></span>(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context,
          <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineDataToRetrieve</a>&nbsp;dataToRetrieve)</code>
 <div class="block">The API to fetch the single entity given the identifier(depending on
  the entity type) in the scope of the given context.</div>
 </td>
 </tr>
 <tr id="i2" class="altColor">
 <td class="colFirst"><code><a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&gt;</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getEntityTypes-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-">getEntityTypes</a></span>(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context)</code>
 <div class="block">The API to list all available entity types of the given context.</div>
 </td>
 </tr>
 <tr id="i3" class="rowColor">
 <td class="colFirst"><code>org.apache.hadoop.yarn.api.records.timeline.TimelineHealth</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html#getHealthStatus--">getHealthStatus</a></span>()</code>
 <div class="block">Check if reader connection is working properly.</div>
 </td>
 </tr>
 </table>
 <ul class="blockList">
 <li class="blockList"><a name="methods.inherited.from.class.org.apache.hadoop.service.Service">
 <!--   -->
 </a>
 <h3>Methods inherited from interface&nbsp;org.apache.hadoop.service.Service</h3>
 <code>close, getBlockers, getConfig, getFailureCause, getFailureState, getLifecycleHistory, getName, getServiceState, getStartTime, init, isInState, registerServiceListener, start, stop, unregisterServiceListener, waitForServiceToStop</code></li>
 </ul>
 </li>
 </ul>
 </li>
 </ul>
 </div>
 <div class="details">
 <ul class="blockList">
 <li class="blockList">
 <!-- ============ METHOD DETAIL ========== -->
 <ul class="blockList">
 <li class="blockList"><a name="method.detail">
 <!--   -->
 </a>
 <h3>Method Detail</h3>
 <a name="getEntity-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getEntity</h4>
 <pre>org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity&nbsp;getEntity(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context,
                                                                             <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineDataToRetrieve</a>&nbsp;dataToRetrieve)
                                                                      throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></pre>
 <div class="block"><p>The API to fetch the single entity given the identifier(depending on
  the entity type) in the scope of the given context.</p></div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>context</code> - Context which defines the scope in which query has to be
     made. Use getters of <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader"><code>TimelineReaderContext</code></a> to fetch context
     fields. Context contains the following :<br>
     <ul>
     <li><b>entityType</b> - Entity type(mandatory).</li>
     <li><b>clusterId</b> - Identifies the cluster(mandatory).</li>
     <li><b>userId</b> - Identifies the user.</li>
     <li><b>flowName</b> - Context flow name.</li>
     <li><b>flowRunId</b> - Context flow run id.</li>
     <li><b>appId</b> - Context app id.</li>
     <li><b>entityId</b> - Entity id.</li>
     </ul>
     Fields in context which are mandatory depends on entity type. Entity
     type is always mandatory. In addition to entity type, below is the list
     of context fields which are mandatory, based on entity type.<br>
     <ul>
     <li>If entity type is YARN_FLOW_RUN (i.e. query to fetch a specific flow
     run), clusterId, userId, flowName and flowRunId are mandatory.</li>
     <li>If entity type is YARN_APPLICATION (i.e. query to fetch a specific
     app), query is within the scope of clusterId, userId, flowName,
     flowRunId and appId. But out of this, only clusterId and appId are
     mandatory. If only clusterId and appId are supplied, backend storage
     must fetch the flow context information i.e. userId, flowName and
     flowRunId first and based on that, fetch the app. If flow context
     information is also given, app can be directly fetched.
     </li>
     <li>For other entity types (i.e. query to fetch generic entity), query
     is within the scope of clusterId, userId, flowName, flowRunId, appId,
     entityType and entityId. But out of this, only clusterId, appId,
     entityType and entityId are mandatory. If flow context information is
     not supplied, backend storage must fetch the flow context information
     i.e. userId, flowName and flowRunId first and based on that, fetch the
     entity. If flow context information is also given, entity can be
     directly queried.
     </li>
     </ul></dd>
 <dd><code>dataToRetrieve</code> - Specifies which data to retrieve for the entity. Use
     getters of TimelineDataToRetrieve class to fetch dataToRetrieve
     fields. All the dataToRetrieve fields are optional. Refer to
     <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader"><code>TimelineDataToRetrieve</code></a> for details.</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>A <cite>TimelineEntity</cite> instance or null. The entity will
     contain the metadata plus the given fields to retrieve.<br>
     If entityType is YARN_FLOW_RUN, entity returned is of type
     <cite>FlowRunEntity</cite>.<br>
     For all other entity types, entity returned is of type
     <cite>TimelineEntity</cite>.</dd>
 <dt><span class="throwsLabel">Throws:</span></dt>
 <dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code> - if there is an exception encountered while fetching
     entity from backend storage.</dd>
 </dl>
 </li>
 </ul>
 <a name="getEntities-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve-">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getEntities</h4>
 <pre><a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity&gt;&nbsp;getEntities(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context,
                                                                                    <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineEntityFilters.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineEntityFilters</a>&nbsp;filters,
                                                                                    <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineDataToRetrieve</a>&nbsp;dataToRetrieve)
                                                                             throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></pre>
 <div class="block"><p>The API to search for a set of entities of the given entity type in
  the scope of the given context which matches the given predicates. The
  predicates include the created time window, limit to number of entities to
  be returned, and the entities can be filtered by checking whether they
  contain the given info/configs entries in the form of key/value pairs,
  given metrics in the form of metricsIds and its relation with metric
  values, given events in the form of the Ids, and whether they relate to/are
  related to other entities. For those parameters which have multiple
  entries, the qualified entity needs to meet all or them.</p></div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>context</code> - Context which defines the scope in which query has to be
     made. Use getters of <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader"><code>TimelineReaderContext</code></a> to fetch context
     fields. Context contains the following :<br>
     <ul>
     <li><b>entityType</b> - Entity type(mandatory).</li>
     <li><b>clusterId</b> - Identifies the cluster(mandatory).</li>
     <li><b>userId</b> - Identifies the user.</li>
     <li><b>flowName</b> - Context flow name.</li>
     <li><b>flowRunId</b> - Context flow run id.</li>
     <li><b>appId</b> - Context app id.</li>
     </ul>
     Although entityIdPrefix and entityId are also part of context,
     it has no meaning for getEntities.<br>
     Fields in context which are mandatory depends on entity type. Entity
     type is always mandatory. In addition to entity type, below is the list
     of context fields which are mandatory, based on entity type.<br>
     <ul>
     <li>If entity type is YARN_FLOW_ACTIVITY (i.e. query to fetch flows),
     only clusterId is mandatory.
     </li>
     <li>If entity type is YARN_FLOW_RUN (i.e. query to fetch flow runs),
     clusterId, userId and flowName are mandatory.</li>
     <li>If entity type is YARN_APPLICATION (i.e. query to fetch apps), we
     can either get all apps within the context of flow name or within the
     context of flow run. If apps are queried within the scope of flow name,
     clusterId, userId and flowName are supplied. If they are queried within
     the scope of flow run, clusterId, userId, flowName and flowRunId are
     supplied.</li>
     <li>For other entity types (i.e. query to fetch generic entities), query
     is within the scope of clusterId, userId, flowName, flowRunId, appId and
     entityType. But out of this, only clusterId, appId and entityType are
     mandatory. If flow context information is not supplied, backend storage
     must fetch the flow context information i.e. userId, flowName and
     flowRunId first and based on that, fetch the entities. If flow context
     information is also given, entities can be directly queried.
     </li>
     </ul></dd>
 <dd><code>filters</code> - Specifies filters which restrict the number of entities
     to return. Use getters of TimelineEntityFilters class to fetch
     various filters. All the filters are optional. Refer to
     <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineEntityFilters.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader"><code>TimelineEntityFilters</code></a> for details.</dd>
 <dd><code>dataToRetrieve</code> - Specifies which data to retrieve for each entity. Use
     getters of TimelineDataToRetrieve class to fetch dataToRetrieve
     fields. All the dataToRetrieve fields are optional. Refer to
     <a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineDataToRetrieve.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader"><code>TimelineDataToRetrieve</code></a> for details.</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>A set of <cite>TimelineEntity</cite> instances of the given entity
     type in the given context scope which matches the given predicates
     ordered by enitityIdPrefix(for generic entities only).
     Each entity will only contain
     the metadata(id, type , idPrefix and created time) plus the given
     fields to retrieve.
     <br>
     If entityType is YARN_FLOW_ACTIVITY, entities returned are of type
     <cite>FlowActivityEntity</cite>.<br>
     If entityType is YARN_FLOW_RUN, entities returned are of type
     <cite>FlowRunEntity</cite>.<br>
     For all other entity types, entities returned are of type
     <cite>TimelineEntity</cite>.</dd>
 <dt><span class="throwsLabel">Throws:</span></dt>
 <dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code> - if there is an exception encountered while fetching
     entity from backend storage.</dd>
 </dl>
 </li>
 </ul>
 <a name="getEntityTypes-org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext-">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getEntityTypes</h4>
 <pre><a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&gt;&nbsp;getEntityTypes(<a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderContext.html" title="class in org.apache.hadoop.yarn.server.timelineservice.reader">TimelineReaderContext</a>&nbsp;context)
                     throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></pre>
 <div class="block">The API to list all available entity types of the given context.</div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>context</code> - A context defines the scope of this query. The incoming
  context should contain at least the cluster id and application id.</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>A set of entity types available in the given context.</dd>
 <dt><span class="throwsLabel">Throws:</span></dt>
 <dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code> - if an exception occurred while listing from backend
  storage.</dd>
 </dl>
 </li>
 </ul>
 <a name="getHealthStatus--">
 <!--   -->
 </a>
 <ul class="blockListLast">
 <li class="blockList">
 <h4>getHealthStatus</h4>
 <pre>org.apache.hadoop.yarn.api.records.timeline.TimelineHealth&nbsp;getHealthStatus()</pre>
 <div class="block">Check if reader connection is working properly.</div>
 <dl>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>True if reader connection works as expected, false otherwise.</dd>
 </dl>
 </li>
 </ul>
 </li>
 </ul>
 </li>
 </ul>
 </div>
 </div>
 <!-- ========= END OF CLASS DATA ========= -->
 <!-- ======= START OF BOTTOM NAVBAR ====== -->
 <div class="bottomNav"><a name="navbar.bottom">
 <!--   -->
 </a>
 <div class="skipNav"><a href="#skip.navbar.bottom" title="Skip navigation links">Skip navigation links</a></div>
 <a name="navbar.bottom.firstrow">
 <!--   -->
 </a>
 <ul class="navList" title="Navigation">
 <li><a href="../../../../../../../overview-summary.html">Overview</a></li>
 <li><a href="package-summary.html">Package</a></li>
 <li class="navBarCell1Rev">Class</li>
 <li><a href="class-use/TimelineReader.html">Use</a></li>
 <li><a href="package-tree.html">Tree</a></li>
 <li><a href="../../../../../../../deprecated-list.html">Deprecated</a></li>
 <li><a href="../../../../../../../index-all.html">Index</a></li>
 <li><a href="../../../../../../../help-doc.html">Help</a></li>
 </ul>
 </div>
 <div class="subNav">
 <ul class="navList">
 <li><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineAggregationTrack.html" title="enum in org.apache.hadoop.yarn.server.timelineservice.storage"><span class="typeNameLink">Prev&nbsp;Class</span></a></li>
 <li><a href="../../../../../../../org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.Field.html" title="enum in org.apache.hadoop.yarn.server.timelineservice.storage"><span class="typeNameLink">Next&nbsp;Class</span></a></li>
 </ul>
 <ul class="navList">
 <li><a href="../../../../../../../index.html?org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.html" target="_top">Frames</a></li>
 <li><a href="TimelineReader.html" target="_top">No&nbsp;Frames</a></li>
 </ul>
 <ul class="navList" id="allclasses_navbar_bottom">
 <li><a href="../../../../../../../allclasses-noframe.html">All&nbsp;Classes</a></li>
 </ul>
 <div>
 <script type="text/javascript"><!--
   allClassesLink = document.getElementById("allclasses_navbar_bottom");
   if(window==top) {
     allClassesLink.style.display = "block";
   }
   else {
     allClassesLink.style.display = "none";
   }
   //-->
 </script>
 </div>
 <div>
 <ul class="subNavList">
 <li>Summary:&nbsp;</li>
 <li><a href="#nested.class.summary">Nested</a>&nbsp;|&nbsp;</li>
 <li>Field&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method.summary">Method</a></li>
 </ul>
 <ul class="subNavList">
 <li>Detail:&nbsp;</li>
 <li>Field&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method.detail">Method</a></li>
 </ul>
 </div>
 <a name="skip.navbar.bottom">
 <!--   -->
 </a></div>
 <!-- ======== END OF BOTTOM NAVBAR ======= -->
 <p class="legalCopy"><small>Copyright &#169; 2008&#x2013;2021 <a href="https://www.apache.org">Apache Software Foundation</a>. All rights reserved.</small></p>
 </body>
 </html>