package com.manning.hip.ch12.crunch;
import com.cloudera.crunch.*;
import com.cloudera.crunch.impl.mr.MRPipeline;
import com.cloudera.crunch.lib.Aggregate;
import com.cloudera.crunch.type.PTypeFamily;
import com.manning.hip.common.CommonLogEntry;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import java.io.IOException;
/**
* Parse Apache logs, extract resources, group them and
* then order by popularity.
*/
public class PopularLinks {
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
Path output = new Path(args[1]);
output.getFileSystem(conf).delete(output, true);
// Create an object to coordinate pipeline creation and execution.
Pipeline pipeline = new MRPipeline(PopularLinks.class, conf);
// Reference a given text file as a collection of Strings.
PCollection<String> lines = pipeline.readTextFile(args[0]);
// Define a function that splits each line in a PCollection of Strings into a
// PCollection made up of the individual words in the file.
PCollection<CommonLogEntry> logs = CrunchUtils.logs(lines);
PCollection<String> resources = extractFilterResources(logs);
PTable<String, Long> counts = Aggregate.count(resources);
// Instruct the pipeline to write the resulting counts to a text file.
pipeline.writeTextFile(counts, args[1]);
// Execute the pipeline as a MapReduce.
pipeline.done();
}
public static PCollection<String> extractFilterResources(PCollection<CommonLogEntry> logs) {
PTypeFamily tf = logs.getTypeFamily();
return logs.parallelDo(
"resource-extract-filter",
new DoFn<CommonLogEntry, String>() {
@Override
public void process(CommonLogEntry input, Emitter<String> emitter) {
if (!"127.0.0.1".equals(input.getRemoteAddress())) {
emitter.emit(input.getResource());
}
}
}, tf.strings());
}
}