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Date: Wed, 27 Jul 2011 15:03:00 +0800
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 <CABx=M6Q6fp55xcWGAC_Dt-tiLDrkgWth83qqHA_fy0oG1=2SVQ@mail.gmail.com>
Subject: About the DistributedCache
From: Weiwei Li <hadoop.li@gmail.com>
To: general@hadoop.apache.org
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Hi,
I have met some problem about the DistributedCache.

There is a document called 'model.txt',  I want every mapper can read it
because there are some public data in it.
So, I use the DistributedCache.

1.In the main()
DistributedCache.createSymlink(conf);
String path =3D "/user/Li/model/model.txt";
Path filePath =3D new Path(path);
String uriWithLink =3D filePath.toUri().toString() + "#" + "model.txt";
System.out.println(uriWithLink);
DistributedCache.addCacheFile(new URI(uriWithLink), conf);

2.In the Mapper()
protected void setup(Context context) throws
IOException,InterruptedException {
  System.out.println("Now, use the distributed cache and syslink");
try {


                FileReader reader =3D new FileReader("model.txt");
BufferedReader br =3D new BufferedReader(reader); String s1 =3D null; while=
 ((s1
=3D br.readLine()) !=3D null) { System.out.println(s1); } br.close();
reader.close();


} catch (Exception e) {
e.printStackTrace();
}
}

3.When run it, in the Task logs.
java.io.FileNotFoundException: model.txt (=BE=DC=BE=F8=B7=C3=CE=CA=A1=A3)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:120)
at java.io.FileInputStream.<init>(FileInputStream.java:79)
at java.io.FileReader.<init>(FileReader.java:41)
at
NB.NBClusterTrain.UseDistributedCacheBySymbolicLink(NBClusterTrain.java:24)
at NB.NBClusterTrain$NBClusterTrainMapper.setup(NBClusterTrain.java:45)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:142)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:621)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305)
at org.apache.hadoop.mapred.Child.main(Child.java:170)

4.When I use /bin/hadoop fs -cat /user/Li/model/model.txt, This can be read=
.

What do you think can I do?
Thank you!

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