public static void main(String[] args) throws Exception {
final String NAME_NODE = "hdfs://sandbox.hortonworks.com:8020";
Configuration conf = new Configuration();
Job job = Job.getInstance(conf);
job.setJarByClass(WordCount.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
job.setOutputKeyClass(IntWritable.class);
job.setOutputValueClass(NullWritable.class);
if (args.length > 2) {
job.setNumReduceTasks(Integer.parseInt(args[2]));
}
job.setMapperClass(CountMapper.class);
job.setReducerClass(CountReducer.class);
job.setJarByClass(WordCount.class);
job.setNumReduceTasks(1);
FileInputFormat.addInputPath(job, new Path(args[0] + "data/plot_summaries.txt"));
FileSystem fs = FileSystem.get(conf);
// handle (e.g. delete) existing output path
Path outputDestination = new Path(args[0] + args[1]);
if (fs.exists(outputDestination)) {
fs.delete(outputDestination, true);
}
// set output path & start job1
FileOutputFormat.setOutputPath(job, outputDestination);
int jobCompletionStatus = job.waitForCompletion(true) ? 0 : 1;
}
/**
* Create a map and reduce Hadoop job. Does not set the name on the job.
* @param inputPath The input {@link org.apache.hadoop.fs.Path}
* @param outputPath The output {@link org.apache.hadoop.fs.Path}
* @param inputFormat The {@link org.apache.hadoop.mapreduce.InputFormat}
* @param mapper The {@link org.apache.hadoop.mapreduce.Mapper} class to use
* @param mapperKey The {@link org.apache.hadoop.io.Writable} key class. If the Mapper is a no-op, this value may be null
* @param mapperValue The {@link org.apache.hadoop.io.Writable} value class. If the Mapper is a no-op, this value may be null
* @param reducer The {@link org.apache.hadoop.mapreduce.Reducer} to use
* @param reducerKey The reducer key class.
* @param reducerValue The reducer value class.
* @param outputFormat The {@link org.apache.hadoop.mapreduce.OutputFormat}.
* @param conf The {@link org.apache.hadoop.conf.Configuration} to use.
* @return The {@link org.apache.hadoop.mapreduce.Job}.
* @throws IOException if there is a problem with the IO.
*
* @see #getCustomJobName(String, org.apache.hadoop.mapreduce.JobContext, Class, Class)
* @see #prepareJob(org.apache.hadoop.fs.Path, org.apache.hadoop.fs.Path, Class, Class, Class, Class, Class, org.apache.hadoop.conf.Configuration)
*/
@SuppressWarnings("rawtypes")
public static Job prepareJob(Path inputPath,
Path outputPath,
Class<? extends InputFormat> inputFormat,
Class<? extends Mapper> mapper,
Class<? extends Writable> mapperKey,
Class<? extends Writable> mapperValue,
Class<? extends Reducer> reducer,
Class<? extends Writable> reducerKey,
Class<? extends Writable> reducerValue,
Class<? extends OutputFormat> outputFormat,
Configuration conf) throws IOException {
//Job job = new Job(new Configuration(conf));
Job job = Job.getInstance(conf);
Configuration jobConf = job.getConfiguration();
if (reducer.equals(Reducer.class)) {
if (mapper.equals(Mapper.class)) {
throw new IllegalStateException("Can't figure out the user class jar file from mapper/reducer");
}
job.setJarByClass(mapper);
} else {
job.setJarByClass(reducer);
}
job.setInputFormatClass(inputFormat);
jobConf.set("mapred.input.dir", inputPath.toString());
job.setMapperClass(mapper);
if (mapperKey != null) {
job.setMapOutputKeyClass(mapperKey);
}
if (mapperValue != null) {
job.setMapOutputValueClass(mapperValue);
}
jobConf.setBoolean("mapred.compress.map.output", true);
job.setReducerClass(reducer);
job.setOutputKeyClass(reducerKey);
job.setOutputValueClass(reducerValue);
job.setOutputFormatClass(outputFormat);
jobConf.set("mapred.output.dir", outputPath.toString());
return job;
}
public int run(String[] args) throws Exception {
Path tempDir = new Path("/user/akhfa/temp");
Configuration conf = new Configuration();
Job job = Job.getInstance(conf, "word count");
job.setJarByClass(AuthorCounter.class);
job.setMapperClass(TokenizerMapper.class);
job.setCombinerClass(IntSumReducer.class);
job.setReducerClass(IntSumReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(LongWritable.class);
job.setOutputFormatClass(SequenceFileOutputFormat.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, tempDir);
System.exit(job.waitForCompletion(true) ? 0 : 1);
return 0;
}