0x00 ? ?緣由
由于我們從Hadoop的Apache網(wǎng)站上下載的hadoop包是在32位機器上編譯的。因此，如果我們的機器的64位的，在使用的時候就會出現(xiàn)問題。所以，我們要在64位機器上重新編譯hadoop。
0x01 ? ?準備
OS: CentOS6 64位 ? ? ? ?Hadoop版本：2.6.0
Hadoop2.6.0源碼下載地址：
http://archive.apache.org/dist/hadoop/common/hadoop-2.6.0/hadoop-2.6.0-src.tar.gz
0x02 ? ?編譯前的準備工作
參考BUILDING.txt
hadoop2.6.0目錄下，有一個BUILDING.txt文件，這是編譯的說明。
Build instructions for Hadoop
------------------------------------------------------------------
Requirements:
* Unix System
* JDK 1.6+
* Maven 3.0 or later
* Findbugs 1.3.9 (if running findbugs)
* ProtocolBuffer 2.5.0
* CMake 2.6 or newer (if compiling native code)
* Zlib devel (if compiling native code)
* openssl devel ( if compiling native hadoop-pipes )
* Internet connection for first build (to fetch all Maven and Hadoop dependencies)
------------------------------------------------------------------
把JDK、Maven、ProtocolBuffer2.5.0、Cmake、zlib、openssl-devel先安裝好
0x03 ? ?編譯
依然參考BUILDING.txt
------------------------------------------------------------------
Building distributions:
Create binary distribution without native code and without documentation:
$ mvn package -Pdist -DskipTests -Dtar
Create binary distribution with native code and with documentation:
$ mvn package -Pdist,native,docs -DskipTests -Dtar
Create source distribution:
$ mvn package -Psrc -DskipTests
Create source and binary distributions with native code and documentation:
$ mvn package -Pdist,native,docs,src -DskipTests -Dtar
Create a local staging version of the website (in /tmp/hadoop-site)
$ mvn clean site; mvn site:stage -DstagingDirectory=/tmp/hadoop-site
------------------------------------------------------------------
進入Hadoop2.6.0目錄下：
這里我們使用：?mvn package -Pdist,native,docs,src -DskipTests -Dtar來編譯
注：為了防止在編譯的時候出現(xiàn)內(nèi)存溢出的錯誤，我們需要手動指定一下maven使用內(nèi)存的大小
Handling out of memory errors in builds
------------------------------------------------------------------
If the build process fails with an out of memory error, you should be able to fix
it by increasing the memory used by maven -which can be done via the environment
variable MAVEN_OPTS.
Here is an example setting to allocate between 256 and 512 MB of heap space to
Maven
export MAVEN_OPTS="-Xms256m -Xmx512m"
------------------------------------------------------------------
編譯順利的話，一個小時左右，就能完成編譯。
編譯好生成的hadoop文件在這個目錄下：hadoop-2.6.0-src/hadoop-dist/target/
有一個文件：hadoop-2.6.0.tar.gz
就是我們編譯好的hadoop2.6.0
0x04 ? ?編譯時遇到的幾個錯誤
-錯誤1：
Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.8.1:jar (module-javadocs) on project hadoop-annotations: MavenReportException: Error while creating archive:
[ERROR] Exit code: 1 - /opt/hadoop-2.6.0-src/hadoop-common-project/hadoop-annotations/src/main/java/org/apache/hadoop/classification/InterfaceStability.java:27: error: unexpected end tag:
解決辦法：在編譯命令后面加個Dmaven.javadoc.skip=true的參數(shù)即可
mvn clean package -Pdist,native,docs,src -DskipTests -Dtar -Dmaven.javadoc.skip=true
-錯誤2：
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.7:run (site) on project hadoop-common: An Ant BuildException has occured: input file /opt/hadoop-2.6.0-src/hadoop-common-project/hadoop-common/target/findbugsXml.xml does not exist
[ERROR] around Ant part ...... @ 44:234 in /opt/hadoop-2.6.0-src/hadoop-common-project/hadoop-common/target/antrun/build-main.xml
解決辦法：去掉編譯命令中的docs參數(shù)
mvn clean package -Pdist,native,src -DskipTests -Dtar -Dmaven.javadoc.skip=true
解決了這兩個報錯，編譯應該就沒有什么問題了。
我自己編譯的時候遇到了這兩個報錯，編譯hadoop2.5.2的方法同上！
可以看到，編譯完成用了20多分鐘。不同的機器配置，可能耗費的時間會有所不同。
不足之處，請批評指正。
如有問題，請私信聯(lián)系。
謝謝！
