[154] | 1 | /** |
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| 2 | * Medium length for events |
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| 3 | * |
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| 4 | * @author cristina |
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| 5 | */ |
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| 6 | |
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| 7 | package org.PP; |
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| 8 | |
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| 9 | import java.io.IOException; |
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| 10 | import java.util.*; |
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| 11 | |
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| 12 | import org.apache.hadoop.fs.Path; |
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| 13 | import org.apache.hadoop.conf.*; |
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| 14 | import org.apache.hadoop.io.*; |
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| 15 | import org.apache.hadoop.mapred.*; |
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| 16 | import org.apache.hadoop.util.*; |
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| 17 | |
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| 18 | public class MediumEvents_straight { |
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| 19 | |
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| 20 | public static class Map extends MapReduceBase implements |
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| 21 | Mapper<LongWritable, Text, Text, DoubleWritable> { |
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| 22 | |
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| 23 | public void map(LongWritable key, Text value, |
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| 24 | OutputCollector<Text, DoubleWritable> output, Reporter reporter) |
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| 25 | throws IOException { |
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| 26 | |
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| 27 | String line = value.toString(); |
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| 28 | // skip comments |
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| 29 | if (!line.startsWith("#")) { |
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| 30 | // collons 7 and 8 are start, end time of job respectively |
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| 31 | StringTokenizer tokenizer = new StringTokenizer(line); |
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| 32 | int count = 0; |
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| 33 | Double start = new Double(0), end = new Double(0), duration = new Double( |
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| 34 | 0); |
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| 35 | while (tokenizer.hasMoreTokens()) { |
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| 36 | count++; |
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| 37 | String token = tokenizer.nextToken(); |
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| 38 | if (count == 7) |
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| 39 | start = Double.parseDouble(token); |
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| 40 | if (count == 8) { |
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| 41 | end = Double.parseDouble(token); |
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| 42 | // stop, we have all the information |
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| 43 | break; |
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| 44 | } |
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| 45 | } |
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| 46 | |
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| 47 | duration = end - start; |
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| 48 | output.collect(new Text("medium duration"), new DoubleWritable(duration)); |
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| 49 | } |
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| 50 | } |
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| 51 | } |
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| 52 | |
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| 53 | public static class Reduce extends MapReduceBase implements |
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| 54 | Reducer<Text, DoubleWritable, Text, DoubleWritable> { |
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| 55 | |
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| 56 | public void reduce(Text key, Iterator<DoubleWritable> values, |
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| 57 | OutputCollector<Text, DoubleWritable> output, Reporter reporter) |
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| 58 | throws IOException { |
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| 59 | Double sum = new Double(0); |
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| 60 | Long count = new Long(0); |
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| 61 | Double med = new Double(0); |
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| 62 | |
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| 63 | while (values.hasNext()) { |
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| 64 | count++; |
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| 65 | sum += values.next().get(); |
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| 66 | } |
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| 67 | if (count > 0) |
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| 68 | med = sum / count; |
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| 69 | else |
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| 70 | med = new Double(0); |
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| 71 | output.collect(key, new DoubleWritable(med)); |
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| 72 | |
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| 73 | } |
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| 74 | } |
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| 75 | |
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| 76 | |
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| 77 | |
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| 78 | public static void main(String[] args) throws Exception { |
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| 79 | JobConf conf = new JobConf(MediumEvents_straight.class); |
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| 80 | conf.setJobName("MediumEvents_straight"); |
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| 81 | |
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| 82 | conf.setOutputKeyClass(Text.class); |
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| 83 | conf.setOutputValueClass(DoubleWritable.class); |
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| 84 | |
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| 85 | conf.setMapperClass(Map.class); |
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| 86 | //conf.setCombinerClass(Reduce.class); !! there shouldn't be any reducer as it approximates!! |
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| 87 | conf.setReducerClass(Reduce.class); |
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| 88 | |
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| 89 | conf.setInputFormat(TextInputFormat.class); |
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| 90 | conf.setOutputFormat(TextOutputFormat.class); |
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| 91 | |
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| 92 | FileInputFormat.setInputPaths(conf, new Path(args[0])); |
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| 93 | FileOutputFormat.setOutputPath(conf, new Path(args[1])); |
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| 94 | |
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| 95 | conf.setNumReduceTasks(5); |
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| 96 | |
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| 97 | JobClient.runJob(conf); |
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| 98 | } |
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| 99 | } |
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