From 0a8c903d3f43eb4fc7c0327e04caf12f8cf5b949 Mon Sep 17 00:00:00 2001
From: Chen Liang <cliang@apache.org>
Date: Thu, 29 Jun 2017 14:43:30 -0700
Subject: [PATCH] HDFS-12050. Ozone: StorageHandler: Implementation of close
 for releasing resources during shutdown. Contributed by Nandakumar.

---
 .../org/apache/hadoop/scm/XceiverClientManager.java    |  9 +++++++++
 .../hdfs/server/datanode/ObjectStoreHandler.java       |  1 +
 .../hadoop/ozone/web/interfaces/StorageHandler.java    |  5 +++++
 .../ozone/web/localstorage/LocalStorageHandler.java    |  5 +++++
 .../ozone/web/storage/DistributedStorageHandler.java   | 10 ++++++++++
 5 files changed, 30 insertions(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/XceiverClientManager.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/XceiverClientManager.java
index 9a5f68dceb..62e5af1eaf 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/XceiverClientManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/XceiverClientManager.java
@@ -154,4 +154,13 @@ public XceiverClientSpi call() throws Exception {
       throw new IOException("Exception getting XceiverClient.", e);
     }
   }
+
+  /**
+   * Close and remove all the cached clients.
+   */
+  public void close() {
+    //closing is done through RemovalListener
+    clientCache.invalidateAll();
+    clientCache.cleanUp();
+  }
 }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ObjectStoreHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ObjectStoreHandler.java
index 0bcb0588d4..ab89ede59b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ObjectStoreHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ObjectStoreHandler.java
@@ -177,6 +177,7 @@ public StorageHandler getStorageHandler() {
   @Override
   public void close() {
     LOG.info("Closing ObjectStoreHandler.");
+    storageHandler.close();
     if (this.storageContainerLocationClient != null) {
       this.storageContainerLocationClient.close();
     }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/interfaces/StorageHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/interfaces/StorageHandler.java
index 52eb349e77..05f12e435a 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/interfaces/StorageHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/interfaces/StorageHandler.java
@@ -273,4 +273,9 @@ LengthInputStream newKeyReader(KeyArgs args)
    * @throws IOException
    */
   ListKeys listKeys(ListArgs args) throws IOException, OzoneException;
+
+  /**
+   * Closes all the opened resources.
+   */
+  void close();
 }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/localstorage/LocalStorageHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/localstorage/LocalStorageHandler.java
index cb8db32387..387eb16fce 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/localstorage/LocalStorageHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/localstorage/LocalStorageHandler.java
@@ -353,4 +353,9 @@ public ListKeys listKeys(ListArgs args) throws IOException, OzoneException {
 
   }
 
+  @Override
+  public void close() {
+    //No resource to close, do nothing.
+  }
+
 }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/storage/DistributedStorageHandler.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/storage/DistributedStorageHandler.java
index dfd0a96ec3..a6887fe3f1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/storage/DistributedStorageHandler.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/storage/DistributedStorageHandler.java
@@ -509,4 +509,14 @@ private static String dateToString(Date date) {
     sdf.setTimeZone(TimeZone.getTimeZone(OzoneConsts.OZONE_TIME_ZONE));
     return sdf.format(date);
   }
+
+  /**
+   * Closes DistributedStorageHandler.
+   */
+  @Override
+  public void close() {
+    if(xceiverClientManager != null) {
+      xceiverClientManager.close();
+    }
+  }
 }