From ce01f2ab1d1967fc86e934b99f4f815abbf7e9bb Mon Sep 17 00:00:00 2001
From: Harsh J <harsh@apache.org>
Date: Mon, 6 Feb 2012 05:37:36 +0000
Subject: [PATCH] HDFS-2868. svn merge -c 1240897 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1240899 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt                | 6 +-----
 .../org/apache/hadoop/hdfs/server/datanode/DataNode.java   | 3 ++-
 .../apache/hadoop/hdfs/server/datanode/DataNodeMXBean.java | 7 ++++++-
 .../hadoop/hdfs/server/datanode/TestDataNodeMXBean.java    | 5 +++++
 4 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 7ba0131955f..724d06a27fa 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -101,11 +101,7 @@ Release 0.23.1 - UNRELEASED
     HDFS-2814. NamenodeMXBean does not account for svn revision in the version 
     information. (Hitesh Shah via jitendra)
 
-    HDFS-2784. Update hftp and hdfs for host-based token support.
-    (Kihwal Lee via jitendra)
-
-    HDFS-2785. Update webhdfs and httpfs for host-based token support.
-    (Robert Joseph Evans via jitendra)
+    HDFS-2868. Expose xceiver counts via the DataNode MXBean. (harsh)
 
   OPTIMIZATIONS
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
index 007cabace48..abde548346e 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
@@ -1262,7 +1262,8 @@ public class DataNode extends Configured
   }
     
   /** Number of concurrent xceivers per node. */
-  int getXceiverCount() {
+  @Override // DataNodeMXBean
+  public int getXceiverCount() {
     return threadGroup == null ? 0 : threadGroup.activeCount();
   }
     
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNodeMXBean.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNodeMXBean.java
index b4f98625c30..8e80c587420 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNodeMXBean.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNodeMXBean.java
@@ -70,5 +70,10 @@ public interface DataNodeMXBean {
    * @return the cluster id
    */
   public String getClusterId();
-  
+
+  /**
+   * Returns an estimate of the number of Datanode threads
+   * actively transferring blocks.
+   */
+  public int getXceiverCount();
 }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
index eb71d2e65b3..e2954855ea1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMXBean.java
@@ -65,6 +65,11 @@ public class TestDataNodeMXBean {
       String volumeInfo = (String)mbs.getAttribute(mxbeanName, "VolumeInfo");
       Assert.assertEquals(replaceDigits(datanode.getVolumeInfo()),
           replaceDigits(volumeInfo));
+      // Ensure mxbean's XceiverCount is same as the DataNode's
+      // live value.
+      int xceiverCount = (Integer)mbs.getAttribute(mxbeanName,
+          "XceiverCount");
+      Assert.assertEquals(datanode.getXceiverCount(), xceiverCount);
     } finally {
       if (cluster != null) {cluster.shutdown();}
     }