Initialize public static variable in Hadoop through arguments - variables

Question

I have a problem with changing public static variables in Hadoop.
I am trying to pass some values as arguments to the jar file from command line.
here is my code:
public class MyClass {
public static long myvariable1 = 100;
public static class Map extends Mapper<Object, Text, Text, Text> {
public static long myvariabl2 = 200;
public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
}
}
public static class Reduce extends Reducer<Text, Text, Text, Text> {
public void reduce(Text key, Iterable<Text> values, Context context)
throws IOException, InterruptedException {
}
}
public static void main(String[] args) throws Exception {
col_no = Long.parseLong(args[0]);
Map.myvariable1 = Long.parseLong(args[1]);
Map.myvariable2 = Long.parseLong(args[1]);
other stuff here
}
}
But it is not working, myvariable1 & myvaribale2 always have 100 & 200.
I use Hadoop 0.20.203 with Ubuntu 10.04

Answer 1

What you can do to get the same behavior is to store your variables in the Configuration you use to launch the job.
public static class Map extends Mapper<Object, Text, Text, Text> {
public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
String var2String = conf.get("myvariable2");
long myvariable2 = Long.parseLong(var2String);
//etc.
}
}
public static void main(String[] args) throws Exception {
col_no = Long.parseLong(args[0]);
String myvariable1 = args[1];
String myvariable2 = args[1];
// add values to configuration
Configuration conf = new Configuration();
conf.set("myvariable1", myvariable1);
conf.set("myvariable2", myvariable2);
//other stuff here
}