在HBase MapReduce任务中加载本机共享库

Question

    public class VideoFeature{
        // JNI Code Begin
        public native static  float Match(byte[] testFileBytes, byte[] tempFileBytes);
        static {
            System.loadLibrary("JVideoFeatureMatch");
        }
        // JNI Code End
    }

    //  MapReduce
        Configuration conf = HBaseConfiguration.create();

    //  DistributedCache shared library
        DistributedCache.createSymlink(conf);
    //  Both following ways seem work.
    //  DistributedCache.addCacheFile(new URI("/home/danayan/Desktop/libJVideoFeatureMatch.so#JVideoFeatureMatch"), conf);
        DistributedCache.addCacheFile(new URI("hdfs://danayan-pc:9000/lib/libJVideoFeatureMatch.so#libJVideoFeatureMatch.so"), conf);

 public  static class MatchMapper extends TableMapper<Text, IntWritable> {

        @Override
        public void map(ImmutableBytesWritable key, Result values, Context context) throws IOException, InterruptedException {

        // Other codes
        Path[] localFiles = DistributedCache.getLocalCacheFiles(context.getConfiguration());
        for(Path temp:localFiles) {
            String path = temp.toString();
            if(path.contains("JVideoFeatureMatch")) {
                 System.out.println("JVideoFeatureMatch  found !");
            }
        }
}

换句话说，我似乎成功地“分发缓存”了我的共享库，但我不能在Map函数中加载它。

 public  static class MatchMapper extends TableMapper<Text, IntWritable> {

    @Override
    public void map(ImmutableBytesWritable key, Result values, Context context) throws IOException, InterruptedException {
    // Other codes
    int score = (int)VideoFeature.Match(testBytes, tempBytes);
}

当我试图调用JNI类中的静态函数时，会抛出一个'java.lang.Exception':

java.lang.UnsatisfiedLinkError: no libJVideoFeatureMatch in java.library.path.

我还尝试了'system.load()'。并且我考虑过在Linux系统中使用前缀'lib'和后缀'.so'。

  -Djava.library.path=/usr/local/hadoop/lib/native/Linux-amd64-64

本机库指南在hadoop reducer中加载本机库？

我不知道我说得是否清楚，如果不清楚，请告诉我。

Answer 1

>

首先将库复制到HDFS：

bin/hadoop fs -copyFromLocal mylib.so.1 /libraries/mylib.so.1  

工作启动程序应包含以下内容：

DistributedCache.createSymlink(conf);   
DistributedCache.addCacheFile("hdfs://host:port/libraries/mylib.so.1#mylib.so", conf);  

MapReduce任务可以包含：

System.load((new File("mylib.so")).getAbsolutePath());