Hadoop 2.6.0: Basic error “starting MRAppMaster” after installing

Question

I have just started to work with Hadoop 2.

After installing with basic configs, I always failed to run any examples. Has anyone seen this problem and please help me?

Answer 1

Error messages: "Error starting MRAppMaster", "InvocationTargetException", "UnsatisfiedLinkError"

Root cause: Fail to execute the native function "anchorNative" in the class "org.apache.hadoop.security.JniBasedUnixGroupsMapping"

Description: the function "anchorNative" will call a function in the library "libhadoop.so". The path of this library is specified by these environment variables:

export JAVA_LIBRARY_PATH
export HADOOP_COMMON_LIB_NATIVE_DIR

In the Hadoop source code, print the java library class path by

System.err.println( (System.getProperty("java.library.path") );

# result
/home/maidinh/hadoop2/build/hadoop-2.6.0-src/hadoop-dist/target/hadoop-2.6.0/lib/native:
/usr/java/packages/lib/amd64:
/usr/lib64:
/lib64:
/lib:
/usr/lib

Different versions of the library "libhadoop.so" can be found in these locations that make a conflict.

Solution: Except the right path of native library (in hadoop-2.6.0/lib/native), delete all "libhadoop.so" in other directories.

Notes: delete all related libraries of hadoop

rm -r libhadoop*
rm -r libhdfs*