I have taken the Hbase table backup using Hbase Export utility tool .
hbase org.apache.hadoop.hbase.mapreduce.Export "FinancialLineItem" "/project/fricadev/ESGTRF/EXPORT"
This has kicked in mapreduce and transferred all my table data into Output folder . As per the document the file format will of the ouotput file is sequence file . So i ran below code to extract my key and value from the file .
Now i want to run mapreduce to read the key value from the output file but getting below exception
java.lang.Exception: java.io.IOException: Could not find a deserializer for the Value class: 'org.apache.hadoop.hbase.client.Result'. Please ensure that the configuration 'io.serializations' is properly configured, if you're using custom serialization. at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:406) Caused by: java.io.IOException: Could not find a deserializer for the Value class: 'org.apache.hadoop.hbase.client.Result'. Please ensure that the configuration 'io.serializations' is properly configured, if you're using custom serialization. at org.apache.hadoop.io.SequenceFile$Reader.init(SequenceFile.java:1964) at org.apache.hadoop.io.SequenceFile$Reader.initialize(SequenceFile.java:1811) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:1760) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:1774) at org.apache.hadoop.mapreduce.lib.input.SequenceFileRecordReader.initialize(SequenceFileRecordReader.java:50) at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.initialize(MapTask.java:478) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:671) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:330)
Here is my driver code
package SEQ;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class SeqDriver extends Configured implements Tool
{
public static void main(String[] args) throws Exception{
int exitCode = ToolRunner.run(new SeqDriver(), args);
System.exit(exitCode);
}
public int run(String[] args) throws Exception {
if (args.length != 2) {
System.err.printf("Usage: %s needs two arguments files\n",
getClass().getSimpleName());
return -1;
}
String outputPath = args[1];
FileSystem hfs = FileSystem.get(getConf());
Job job = new Job();
job.setJarByClass(SeqDriver.class);
job.setJobName("SequenceFileReader");
HDFSUtil.removeHdfsSubDirIfExists(hfs, new Path(outputPath), true);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.setOutputKeyClass(ImmutableBytesWritable.class);
job.setOutputValueClass(Result.class);
job.setInputFormatClass(SequenceFileInputFormat.class);
job.setMapperClass(MySeqMapper.class);
job.setNumReduceTasks(0);
int returnValue = job.waitForCompletion(true) ? 0:1;
if(job.isSuccessful()) {
System.out.println("Job was successful");
} else if(!job.isSuccessful()) {
System.out.println("Job was not successful");
}
return returnValue;
}
}
Here is my mapper code
package SEQ;
import java.io.IOException;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
public class MySeqMapper extends Mapper <ImmutableBytesWritable, Result, Text, Text>{
@Override
public void map(ImmutableBytesWritable row, Result value,Context context)
throws IOException, InterruptedException {
}
}