From 308b75571b29246cb140096feb22dfc51b271380 Mon Sep 17 00:00:00 2001
From: cnauroth <cnauroth@apache.org>
Date: Sat, 6 Dec 2014 20:12:31 -0800
Subject: [PATCH] HADOOP-11313. Adding a document about NativeLibraryChecker.
 Contributed by Tsuyoshi OZAWA.

(cherry picked from commit 1b3bb9e7a33716c4d94786598b91a24a4b29fe67)
---
 .../hadoop-common/CHANGES.txt                  |  3 +++
 .../src/site/apt/NativeLibraries.apt.vm        | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 8aad8eb899c..6db9eec7265 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -47,6 +47,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11356. Removed deprecated o.a.h.fs.permission.AccessControlException.
     (Li Lu via wheat9)
 
+    HADOOP-11313. Adding a document about NativeLibraryChecker.
+    (Tsuyoshi OZAWA via cnauroth)
+
   OPTIMIZATIONS
 
     HADOOP-11323. WritableComparator#compare keeps reference to byte array.
diff --git a/hadoop-common-project/hadoop-common/src/site/apt/NativeLibraries.apt.vm b/hadoop-common-project/hadoop-common/src/site/apt/NativeLibraries.apt.vm
index 49818af806e..866b4289b8a 100644
--- a/hadoop-common-project/hadoop-common/src/site/apt/NativeLibraries.apt.vm
+++ b/hadoop-common-project/hadoop-common/src/site/apt/NativeLibraries.apt.vm
@@ -164,6 +164,24 @@ Native Libraries Guide
      * If something goes wrong, then:
        <<<INFO util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable>>>
 
+* Check
+
+   NativeLibraryChecker is a tool to check whether native libraries are loaded correctly.
+   You can launch NativeLibraryChecker as follows:
+
+----
+   $ hadoop checknative -a
+   14/12/06 01:30:45 WARN bzip2.Bzip2Factory: Failed to load/initialize native-bzip2 library system-native, will use pure-Java version
+   14/12/06 01:30:45 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library
+   Native library checking:
+   hadoop: true /home/ozawa/hadoop/lib/native/libhadoop.so.1.0.0
+   zlib:   true /lib/x86_64-linux-gnu/libz.so.1
+   snappy: true /usr/lib/libsnappy.so.1
+   lz4:    true revision:99
+   bzip2:  false
+----
+
+
 * Native Shared Libraries
 
    You can load any native shared library using DistributedCache for