Override hadoop - hadoop

Question

I'm running an EMR Activity inside a Data Pipeline analyzing log files and I get the following error when my Pipeline fails:
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://10.211.146.177:9000/home/hadoop/temp-output-s3copy-2013-05-24-00 already exists
at org.apache.hadoop.mapred.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:121)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:944)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:905)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1132)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:905)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:879)
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1316)
at com.valtira.datapipeline.stream.CloudFrontStreamLogProcessors.main(CloudFrontStreamLogProcessors.java:216)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.RunJar.main(RunJar.java:187)
I've tried delete that folder by adding:
FileSystem fs = FileSystem.get(getConf());
fs.delete(new Path("path/to/file"), true); // delete file, true for recursive
but it does not work. Is there a way to override the FileOutputFormat method from Hadoop in java? Is there a way to ignore this error in java?

Answer 1

The path to the file to be deleted changes as the output directory uses date for naming.
There are 2 ways to delete it:
Over shell, try this:
hadoop dfs -rmr hdfs://127.0.0.1:9000/home/hadoop/temp-output-s3copy-*
To do it via Java code:
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.mortbay.log.Log;
public class FSDeletion {
public static void main(String[] args) {
try {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
String fsName = conf.get("fs.default.name", "localhost:9000");
String baseDir = "/home/hadoop/";
String outputDirPattern = fsName + baseDir + "temp-output-s3copy-";
Path[] paths = new Path[1];
paths[0] = new Path(baseDir);
FileStatus[] status = fs.listStatus(paths);
Path[] listedPaths = FileUtil.stat2Paths(status);
for (Path p : listedPaths) {
if (p.toString().startsWith(outputDirPattern)) {
Log.info("Attempting to delete : " + p);
boolean result = fs.delete(p, true);
Log.info("Deleted ? : " + result);
}
}
fs.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}