YARN-5265. Make HBase configuration for the timeline service configurable. Contributed by Joep Rottinghuis.
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
index b8e6a1b..bbfcba8 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java
@@ -2038,6 +2038,15 @@
       + "hbase.coprocessor.app-final-value-retention-milliseconds";
 
   /**
+   * The name for setting that points to an optional HBase configuration
+   * (hbase-site.xml file) with settings that will override the ones found on
+   * the classpath.
+   */
+  public static final String TIMELINE_SERVICE_HBASE_CONFIGURATION_FILE =
+      TIMELINE_SERVICE_PREFIX
+      + "hbase.configuration.file";
+
+  /**
    * The setting that controls how long the final value of a metric of a
    * completed app is retained before merging into the flow sum. Up to this time
    * after an application is completed out-of-order values that arrive can be
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
index 723cb9c..6f62fd8 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml
@@ -2253,6 +2253,18 @@
     <value>prod.</value>
   </property>
 
+  <property>
+    <description> Optional URL to an hbase-site.xml configuration file to be
+    used to connect to the timeline-service hbase cluster. If empty or not
+    specified, then the HBase configuration will be loaded from the classpath.
+    When specified the values in the specified configuration file will override
+    those from the ones that are present on the classpath.
+    </description>
+    <name>yarn.timeline-service.hbase.configuration.file
+    </name>
+    <value></value>
+  </property>
+
   <!--  Shared Cache Configuration -->
 
   <property>
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java
index a384a84..63cd232 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java
@@ -24,7 +24,6 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.service.AbstractService;
@@ -32,6 +31,7 @@
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.reader.TimelineEntityReader;
 import org.apache.hadoop.yarn.server.timelineservice.storage.reader.TimelineEntityReaderFactory;
 
@@ -54,7 +54,7 @@
   @Override
   public void serviceInit(Configuration conf) throws Exception {
     super.serviceInit(conf);
-    hbaseConf = HBaseConfiguration.create(conf);
+    hbaseConf = TimelineStorageUtils.getTimelineServiceHBaseConf(conf);
     conn = ConnectionFactory.createConnection(hbaseConf);
   }
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java
index a8b44f1..df1e460 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java
@@ -26,7 +26,6 @@
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.service.AbstractService;
@@ -50,6 +49,7 @@
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongKeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TypedBufferedMutator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumn;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
@@ -112,7 +112,8 @@
   @Override
   protected void serviceInit(Configuration conf) throws Exception {
     super.serviceInit(conf);
-    Configuration hbaseConf = HBaseConfiguration.create(conf);
+    Configuration hbaseConf =
+        TimelineStorageUtils.getTimelineServiceHBaseConf(conf);
     conn = ConnectionFactory.createConnection(hbaseConf);
     entityTable = new EntityTable().getTableMutator(hbaseConf, conn);
     appToFlowTable = new AppToFlowTable().getTableMutator(hbaseConf, conn);
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineSchemaCreator.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineSchemaCreator.java
index 33f5449..176562b 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineSchemaCreator.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineSchemaCreator.java
@@ -34,13 +34,13 @@
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.util.GenericOptionsParser;
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunTable;
@@ -68,7 +68,8 @@
 
   public static void main(String[] args) throws Exception {
 
-    Configuration hbaseConf = HBaseConfiguration.create();
+    Configuration hbaseConf =
+        TimelineStorageUtils.getTimelineServiceHBaseConf(null);
     // Grab input args and allow for -Dxyz style arguments
     String[] otherArgs = new GenericOptionsParser(hbaseConf, args)
         .getRemainingArgs();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineStorageUtils.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineStorageUtils.java
index 99e16a1..3285b06 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineStorageUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineStorageUtils.java
@@ -18,6 +18,8 @@
 package org.apache.hadoop.yarn.server.timelineservice.storage.common;
 
 import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -29,14 +31,17 @@
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineCompareFilter;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineCompareOp;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineExistsFilter;
@@ -563,4 +568,41 @@
     }
     return appId;
   }
+
+
+  /**
+   * @param conf Yarn configuration. Used to see if there is an explicit config
+   *          pointing to the HBase config file to read. If null then a new
+   *          HBase configuration will be returned.
+   * @return a configuration with the HBase configuration from the classpath,
+   *         optionally overwritten by the timeline service configuration URL if
+   *         specified.
+   * @throws MalformedURLException if a timeline service HBase configuration URL
+   *           is specified but is a malformed URL.
+   */
+  public static Configuration getTimelineServiceHBaseConf(Configuration conf)
+      throws MalformedURLException {
+    Configuration hbaseConf;
+
+    if (conf == null) {
+      return HBaseConfiguration.create();
+    }
+
+    String timelineServiceHBaseConfFileURL =
+        conf.get(YarnConfiguration.TIMELINE_SERVICE_HBASE_CONFIGURATION_FILE);
+    if (timelineServiceHBaseConfFileURL != null
+        && timelineServiceHBaseConfFileURL.length() > 0) {
+      // create a clone so that we don't mess with out input one
+      hbaseConf = new Configuration(conf);
+      Configuration plainHBaseConf = new Configuration(false);
+      URL hbaseSiteXML = new URL(timelineServiceHBaseConfFileURL);
+      plainHBaseConf.addResource(hbaseSiteXML);
+      HBaseConfiguration.merge(hbaseConf, plainHBaseConf);
+    } else {
+      // default to what is on the classpath
+      hbaseConf = HBaseConfiguration.create(conf);
+    }
+    return hbaseConf;
+  }
+
 }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
index 05a80c4..9a06b47 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
@@ -153,6 +153,7 @@
 | `yarn.timeline-service.address` | Address for the Timeline server to start the RPC server. Defaults to `${yarn.timeline-service.hostname}:10200`. |
 | `yarn.timeline-service.webapp.address` | The http address of the Timeline service web application. Defaults to `${yarn.timeline-service.hostname}:8188`. |
 | `yarn.timeline-service.webapp.https.address` | The https address of the Timeline service web application. Defaults to `${yarn.timeline-service.hostname}:8190`. |
+| **`yarn.timeline-service.hbase.configuration.file`** | Optional URL to an hbase-site.xml configuration file to be used to connect to the timeline-service hbase cluster. If empty or not specified, then the HBase configuration will be loaded from the classpath. When specified the values in the specified configuration file will override those from the ones that are present on the classpath. Defaults to `null`. |
 | **`yarn.timeline-service.writer.flush-interval-seconds`** | The setting that controls how often the timeline collector flushes the timeline writer. Defaults to `60`. |
 | **`yarn.timeline-service.app-collector.linger-period.ms`** | Time period till which the application collector will be alive in NM, after the  application master container finishes. Defaults to `1000` (1 second). |
 | **`yarn.timeline-service.timeline-client.number-of-async-entities-to-merge`** | Time line V2 client tries to merge these many number of async entities (if available) and then call the REST ATS V2 API to submit. Defaults to `10`. |
@@ -249,7 +250,22 @@
 ```
 
 Also, add the `hbase-site.xml` configuration file to the client Hadoop cluster configuration so
-that it can write data to the Apache HBase cluster you are using.
+that it can write data to the Apache HBase cluster you are using, or set
+`yarn.timeline-service.hbase.configuration.file` to the file URL pointing to
+`hbase-site.xml` for the same. For example:
+
+```
+<property>
+  <description> Optional URL to an hbase-site.xml configuration file to be
+  used to connect to the timeline-service hbase cluster. If empty or not
+  specified, then the HBase configuration will be loaded from the classpath.
+  When specified the values in the specified configuration file will override
+  those from the ones that are present on the classpath.
+  </description>
+  <name>yarn.timeline-service.hbase.configuration.file</name>
+  <value>file:/etc/hbase/hbase-ats-dc1/hbase-site.xml</value>
+</property>
+```
 
 #### Running Timeline Service v.2
 Restart the resource manager as well as the node managers to pick up the new configuration. The