问题
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?
And the error is something like
Error starting MRAppMaster
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
This is the log
20152015-01-06 11:56:23,194 INFO [main] org.apache.hadoop.mapreduce.v2.app.MRAppMaster: Created MRAppMaster for application appattempt_1420510526926_0002_000001
2015-01-06 11:56:23,362 FATAL [main] org.apache.hadoop.mapreduce.v2.app.MRAppMaster: Error starting MRAppMaster
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:131)
at org.apache.hadoop.security.Groups.<init>(Groups.java:70)
at org.apache.hadoop.security.Groups.<init>(Groups.java:66)
at org.apache.hadoop.security.Groups.getUserToGroupsMappingService(Groups.java:280)
at org.apache.hadoop.security.UserGroupInformation.initialize(UserGroupInformation.java:271)
at org.apache.hadoop.security.UserGroupInformation.setConfiguration(UserGroupInformation.java:299)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.initAndStartAppMaster(MRAppMaster.java:1473)
at org.apache.hadoop.mapreduce.v2.app.MRAppMaster.main(MRAppMaster.java:1429)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:129)
... 7 more
Caused by: java.lang.UnsatisfiedLinkError: org.apache.hadoop.security.JniBasedUnixGroupsMapping.anchorNative()V
at org.apache.hadoop.security.JniBasedUnixGroupsMapping.anchorNative(Native Method)
at org.apache.hadoop.security.JniBasedUnixGroupsMapping.<clinit>(JniBasedUnixGroupsMapping.java:49)
at org.apache.hadoop.security.JniBasedUnixGroupsMappingWithFallback.<init>(JniBasedUnixGroupsMappingWithFallback.java:39)
... 12 more
2015-01-06 11:56:23,366 INFO [main] org.apache.hadoop.util.ExitUtil: Exiting with status 1
回答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*
来源：https://stackoverflow.com/questions/27791518/hadoop-2-6-0-basic-error-starting-mrappmaster-after-installing