If you are reading this blog, I assume that you already have Hadoop(v 2.4.1) installed on your OS X machine and that you are bit annoyed by the following error message

WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform… using builtin-java classes where applicable

If you are only planning to use Hadoop on OS X for development procedures, this error should not bother you. For me it was the same case, but I was just annoyed with this warning message and wanted to try building Native libraries from the source code.

Steps to build Native Hadoop libraries

1. Download source from GitHub

• git clone git@github.com:apache/hadoop.git
• git checkout branch-2.4.1

1. Dependencies
   Install cmake and zlib using homebrew package manager

• brew install cmake
• brew install zlib

1. Run maven command

• mvn package -Pdist,native -DskipTests -Dtar

On linux machines, the above procedure should be enough, but not for MAC OS X with Java 1.7. So for that you have to go with few more changes.

Issues faced on Building Native libraries On Mac OS X

1.Missing tools.jar

If you are building using Java 1.7, you would see an error talking about missing tools.jar, which is a bug in Maven JSPC. The related Jira issue is HADOOP-9350. The JSPC Plugin expects classes.jar in ../Classes folder, so we create a symlink.

error:

Exception in thread “main” java.lang.AssertionError: Missing tools.jar at: /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents
/Home/Classes/classes.jar. Expression: file.exists()

Solution: Create a symbolic link to trick Java into believing that classes.jar is same as tools.jar

• sudo mkdir /usr/libexec/java_home/Classes
• sudo ln -s /usr/libexec/java_home/lib/tools.jar /usr/libexec/java_home/Classes/classes.jar

2. Incompatible source code

Some code in Hadoop v2.4.1 is not compatible with Mac system, so need to apply the patch HADOOP-9648.v2.patch and the related Jira issue is HADOOP-10699

error:

     [exec] /Users/gaurav/GitHub/hadoop/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/security/JniBasedUnixGroupsNetgroupMapping.c:77:26: error: invalid operands to binary expression ('void' and 'int')
     [exec]   if(setnetgrent(cgroup) == 1) {
     [exec]      ~~~~~~~~~~~~~~~~~~~ ^  ~
     [exec] 1 error generated.

Solution: Download the Patch from Jira issue HADOOP-10699. Download link-> HADOOP-9648.v2.patch

• git apply HADOOP-9648.v2.patch
• mvn package -Pdist,native -DskipTests -Dtar

Result

hadoop-dist/target/hadoop-2.4.1/lib/native folder should contain the native libraries. Copy them to hadoop-2.4.1/lib/native folder and restart Hadoop cluster.

References

1. Native Libraries Guide documentation page.
2. Hadoop Git repo
3. HADOOP-10699 V2 Patch
4. Details about Maven JSPC Issue