Hadoop wrapper script not picking up native libs correctly

Originally discussed in https://mail-archives.apache.org/mod_mbox/hadoop-common-user/201111.mbox/%3C4EC3A3AE.7060402%40deri.org%3E

I'm testing out native lib support on our test amd64 test cluster
running 0.20.205 running the following

./bin/hadoop jar hadoop-test-0.20.205.0.jar testsequencefile -seed 0
-count 1000 -compressType RECORD xxx -codec
org.apache.hadoop.io.compress.GzipCodec -check 2

it fails with

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

Looking at

bin/hadoop

it seems to successfully detect that the native libs are available (they
seem to come pre-compiled with 0.20.205 which is nice)

if [ -d "${HADOOP_HOME}/lib/native" ]; then
if [ "x$JAVA_LIBRARY_PATH" != "x" ]; then

JAVA_LIBRARY_PATH=${JAVA_LIBRARY_PATH}:${HADOOP_HOME}/lib/native/${JAVA_PLATFORM}
else
JAVA_LIBRARY_PATH=${HADOOP_HOME}/lib/native/${JAVA_PLATFORM}
fi
fi

and sets JAVA_LIBRARY_PATH to contain them.

Then in the following line, if ${HADOOP_HOME}/lib contains libhadoop.a
(which is seems to in the stock tar) then it proceeds to ignore the
native libs

if [ -e "${HADOOP_PREFIX}/lib/libhadoop.a" ]; then
JAVA_LIBRARY_PATH=${HADOOP_PREFIX}/lib
fi

The libhadoop.a in ${HADOOP_HOME}/lib seems to be a copy of the lib/native/Linux-i386-32 going from the filesizes (and also noted by https://mail-archives.apache.org/mod_mbox/hadoop-common-user/201111.mbox/%3CCAOcnVr2AzUDnN0LFhmTqUmAyujYtvhfkmMm_J0R-bmxw2wU+9A@mail.gmail.com%3E)

hadoop@testhbase01:~$ ls -la hadoop/lib/libhadoop.*
rw-rr- 1 hadoop hadoop 237244 Oct 7 08:20 hadoop/lib/libhadoop.a
rw-rr- 1 hadoop hadoop 877 Oct 7 08:20 hadoop/lib/libhadoop.la
rw-rr- 1 hadoop hadoop 160438 Oct 7 08:20 hadoop/lib/libhadoop.so
rw-rr- 1 hadoop hadoop 160438 Oct 7 08:19 hadoop/lib/libhadoop.so.1.0.0
hadoop@testhbase01:~$ ls -la hadoop/lib/native/Linux-i386-32/
total 728
drwxr-xr-x 3 hadoop hadoop 4096 Nov 15 14:05 .
drwxr-xr-x 5 hadoop hadoop 4096 Oct 7 08:24 ..
rw-rr- 1 hadoop hadoop 237244 Oct 7 08:20 libhadoop.a
rw-rr- 1 hadoop hadoop 877 Oct 7 08:20 libhadoop.la
rw-rr- 1 hadoop hadoop 160438 Oct 7 08:20 libhadoop.so
rw-rr- 1 hadoop hadoop 160438 Oct 7 08:20 libhadoop.so.1
rw-rr- 1 hadoop hadoop 160438 Oct 7 08:20 libhadoop.so.1.0.0

A possible solution includes removing libhadoop.a and friends from ${HADOOP_HOME}/lib and possibly also modifying the hadoop wrapper to remove

if [ -e "${HADOOP_PREFIX}/lib/libhadoop.a" ]; then
JAVA_LIBRARY_PATH=${HADOOP_PREFIX}/lib
fi

unless there is some other reason for this to exist.

This was also noted in a comment to HADOOP-6453