在Centos下hadoop native-library错误

hadoop-2.7.3 + Centos 6.7 64位环境下使用弄一套Hadoop环境过程的一些小事情。

（1）开始检查

[hadoop@xxx6 ~]$ hadoop checknative -a

16/03/21 23:12:46 WARN bzip2.Bzip2Factory: Failed to load/initialize native-bzip2 library system-native, will use pure-Java version

16/03/21 23:12:46 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library

Native library checking:

hadoop: true /home/hadoop/hadoop-2.7.2/lib/native/libhadoop.so

zlib: true /lib64/libz.so.1

snappy: false

lz4: true revision:99

bzip2: false

openssl: false Cannot load libcrypto.so (libcrypto.so: 无法打开共享对象文件: 没有那个文件或目录)!

16/03/21 23:12:46 INFO util.ExitUtil: Exiting with status 1

（2）问题查找

https://issues.apache.org/jira/browse/HADOOP-12845

Google一通下来，才知道这个是hadoop-2.7.2这个版本的BUG，还有待解决，目前只能去回避问题。

On RedHat system (Fedora/Centos/...) the /usr/lib64/libcrypto.so is a link provided by

openssl-devel RPM package which is fine on a build/development host, but devel packages are

not supposed to be installed on Production servers (Hadoop Cluster) and the openssl RPM package

don't include that link which is a problem.

（3）问题解决

可以建立如下符号链接即可：

[hadoop@xxx6 ~]$ cd /usr/lib64/

[hadoop@xxx lib64]$ ln -s libcrypto.so.1.0.1e libcrypto.so

建立符号链接后再检查hadoop native，则现象改变了！

[hadoop@xxx6 ~]$ hadoop checknative -a

16/03/21 23:13:51 WARN bzip2.Bzip2Factory: Failed to load/initialize native-bzip2 library system-native, will use pure-Java version

16/03/21 23:13:51 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library

Native library checking:

hadoop: true /home/hadoop/hadoop-2.7.2/lib/native/libhadoop.so

zlib: true /lib64/libz.so.1

snappy: false

lz4: true revision:99

bzip2: false

openssl: true /usr/lib64/libcrypto.so

16/03/21 23:13:51 INFO util.ExitUtil: Exiting with status 1