getting java.lang.RuntimeException: "advancing post rec#0" - hadoop

Question

I am new to hadoop and I am trying to get max salary of an employee. My data looks like
1231,"","","",4000<br/>
1232,"","","",5000<br/>
..................<br/>
..................<br/>
This is my mapper class, here, I am to trying to emit the full tuple
public class maxmap extends MapReduceBase implements Mapper<LongWritable,Text,Text,employee> {
#Override
public void map(LongWritable key, Text value,
OutputCollector<Text,employee> outputCollector, Reporter reporter)
throws IOException {
// TODO Auto-generated method stub
//TupleWritable tupleWritable= new TupleWritable(new Writable[]{new Text(value.toString().split(",")[1]),
//new Text(value.toString().split(",")[0])
//});Str
String employeeId = value.toString().split(",")[0];
int count =1231;
employee employee=new employee(Integer.parseInt(employeeId), "employeeName", "StemployeeDept", "employeeJoinDt",1231);
//tupleWritable.write();
outputCollector.collect(new Text("max salry"),employee);
}
}
This is my Reducer class
public class maxsalreduce extends MapReduceBase implements Reducer<Text,employee,Text,IntWritable> {
#Override
public void reduce(Text key, Iterator<employee> values,
OutputCollector<Text, IntWritable> collector, Reporter reporter)
throws IOException {
// TODO Auto-generated method stub
System.out.println("in reducer");
while(values.hasNext()){
employee employee=values.next();
System.out.println("employee id"+employee.employeeId);
}
collector.collect(new Text(""), new IntWritable(1));
}
}
This is my employee class
public class employee implements Writable{
public int employeeId;
private String employeeName;
private String employeeDept;
private String employeeJoinDt;
public employee(int employeeId,String employeeName,String employeeDept,String employeeJoinDt,int employeeSalary){
this.employeeId=employeeId;
System.out.println(this.employeeId);
this.employeeName=employeeName;
this.employeeDept=employeeDept;
this.employeeJoinDt=employeeJoinDt;
this.employeeSalary=employeeSalary;
}
public employee() {
// TODO Auto-generated constructor stub
}
public int getEmployeeId() {
return employeeId;
}
public void setEmployeeId(int employeeId) {
this.employeeId = employeeId;
}
public String getEmployeeName() {
return employeeName;
}
public void setEmployeeName(String employeeName) {
this.employeeName = employeeName;
}
public String getEmployeeDept() {
return employeeDept;
}
public void setEmployeeDept(String employeeDept) {
this.employeeDept = employeeDept;
}
public String getEmployeeJoinDt() {
return employeeJoinDt;
}
public void setEmployeeJoinDt(String employeeJoinDt) {
this.employeeJoinDt = employeeJoinDt;
}
public int getEmployeeSalary() {
return employeeSalary;
}
public void setEmployeeSalary(int employeeSalary) {
this.employeeSalary = employeeSalary;
}
private int employeeSalary;
#Override
public void readFields(DataInput input) throws IOException {
// TODO Auto-generated method stubt
System.out.println("employee id is"+input.readInt());
//this.employeeId=input.readInt();
//this.employeeName=input.readUTF();
//this.employeeDept=input.readUTF();
//this.employeeJoinDt=input.readUTF();mployee id
//this.employeeSalary=input.readInt();
new employee(input.readInt(),input.readUTF(),input.readUTF(),input.readUTF(),input.readInt());
}
#Override
public void write(DataOutput output) throws IOException {
// TODO Auto-generated method stub
output.writeInt(this.employeeId);
output.writeUTF(this.employeeName);
output.writeUTF(this.employeeDept);
output.writeUTF(this.employeeJoinDt);
output.writeInt(this.employeeSalary);
}
}
This is my job runner
public class jobrunner {
public static void main(String[] args) throws IOException
{
JobConf jobConf = new JobConf(jobrunner.class);
jobConf.setJobName("Count no of employees");
jobConf.setMapperClass(maxmap.class);
jobConf.setReducerClass(maxsalreduce.class);
FileInputFormat.setInputPaths(jobConf, new Path("hdfs://localhost:9000/employee_data.txt"));
FileOutputFormat.setOutputPath(jobConf,new Path("hdfs://localhost:9000/dummy20.txt"));
jobConf.setOutputKeyClass(Text.class);
jobConf.setOutputValueClass(employee.class);
JobClient.runJob(jobConf);
}
}
This is the exception I am getting
java.lang.RuntimeException: problem advancing post rec#0
at org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1214)
at org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.moveToNext(ReduceTask.java:249)
at org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.next(ReduceTask.java:245)
at tuplewritable.maxsalreduce.reduce(maxsalreduce.java:24)
at tuplewritable.maxsalreduce.reduce(maxsalreduce.java:1)
at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:519)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:420)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:260)
Caused by: java.io.EOFException
at java.io.DataInputStream.readFully(DataInputStream.java:180)
at java.io.DataInputStream.readUTF(DataInputStream.java:592)
at java.io.DataInputStream.readUTF(DataInputStream.java:547)
at tuplewritable.employee.readFields(employee.java:76)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:67)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:40)
at org.apache.hadoop.mapred.Task$ValuesIterator.readNextValue(Task.java:1271)
at org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1211)
... 7 more
13/08/17 20:44:14 INFO mapred.JobClient: map 100% reduce 0%
13/08/17 20:44:14 INFO mapred.JobClient: Job complete: job_local_0001
13/08/17 20:44:14 INFO mapred.JobClient: Counters: 21
13/08/17 20:44:14 INFO mapred.JobClient: File Input Format Counters
13/08/17 20:44:14 INFO mapred.JobClient: Bytes Read=123
13/08/17 20:44:14 INFO mapred.JobClient: FileSystemCounters
13/08/17 20:44:14 INFO mapred.JobClient: FILE_BYTES_READ=146
13/08/17 20:44:14 INFO mapred.JobClient: HDFS_BYTES_READ=123
13/08/17 20:44:14 INFO mapred.JobClient: FILE_BYTES_WRITTEN=39985
13/08/17 20:44:14 INFO mapred.JobClient: Map-Reduce Framework
13/08/17 20:44:14 INFO mapred.JobClient: Map output materialized bytes=270
13/08/17 20:44:14 INFO mapred.JobClient: Map input records=4
13/08/17 20:44:14 INFO mapred.JobClient: Reduce shuffle bytes=0
13/08/17 20:44:14 INFO mapred.JobClient: Spilled Records=4
13/08/17 20:44:14 INFO mapred.JobClient: Map output bytes=256
13/08/17 20:44:14 INFO mapred.JobClient: Total committed heap usage (bytes)=160763904
13/08/17 20:44:14 INFO mapred.JobClient: CPU time spent (ms)=0
13/08/17 20:44:14 INFO mapred.JobClient: Map input bytes=123
13/08/17 20:44:14 INFO mapred.JobClient: SPLIT_RAW_BYTES=92
13/08/17 20:44:14 INFO mapred.JobClient: Combine input records=0
13/08/17 20:44:14 INFO mapred.JobClient: Reduce input records=0
13/08/17 20:44:14 INFO mapred.JobClient: Reduce input groups=0
13/08/17 20:44:14 INFO mapred.JobClient: Combine output records=0
13/08/17 20:44:14 INFO mapred.JobClient: Physical memory (bytes) snapshot=0
13/08/17 20:44:14 INFO mapred.JobClient: Reduce output records=0
13/08/17 20:44:14 INFO mapred.JobClient: Virtual memory (bytes) snapshot=0
13/08/17 20:44:14 INFO mapred.JobClient: Map output records=4
13/08/17 20:44:14 INFO mapred.JobClient: Job Failed: NA
Exception in thread "main" java.io.IOException: Job failed!
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1265)
at tuplewritable.jobrunner.main(jobrunner.java:30)
13/08/17 20:44:14 ERROR hdfs.DFSClient: Exception closing file /dummy20.txt/_temporary/_attempt_local_0001_r_000000_0/part-00000 : org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException: No lease on /dummy20.txt/_temporary/_attempt_local_0001_r_000000_0/part-00000 File does not exist. Holder DFSClient_1595916561 does not have any open files.
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1629)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1620)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFileInternal(FSNamesystem.java:1675)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFile(FSNamesystem.java:1663)
at org.apache.hadoop.hdfs.server.namenode.NameNode.complete(NameNode.java:718)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:563)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1388)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1384)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1083)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1382)
org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException: No lease on /dummy20.txt/_temporary/_attempt_local_0001_r_000000_0/part-00000 File does not exist. Holder DFSClient_1595916561 does not have any open files.
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1629)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1620)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFileInternal(FSNamesystem.java:1675)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFile(FSNamesystem.java:1663)
at org.apache.hadoop.hdfs.server.namenode.NameNode.complete(NameNode.java:718)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:563)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1388)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1384)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1083)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1382)
at org.apache.hadoop.ipc.Client.call(Client.java:1066)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:225)
at $Proxy1.complete(Unknown Source)
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.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:82)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:59)
at $Proxy1.complete(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.closeInternal(DFSClient.java:3894)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.close(DFSClient.java:3809)
at org.apache.hadoop.hdfs.DFSClient$LeaseChecker.close(DFSClient.java:1342)
at org.apache.hadoop.hdfs.DFSClient.close(DFSClient.java:275)
at org.apache.hadoop.hdfs.DistributedFileSystem.close(DistributedFileSystem.java:328)
at org.apache.hadoop.fs.FileSystem$Cache.closeAll(FileSystem.java:1446)
at org.apache.hadoop.fs.FileSystem.closeAll(FileSystem.java:277)
at org.apache.hadoop.fs.FileSystem$ClientFinalizer.run(FileSystem.java:260)

Answer 1

You have these going wrong in your classes.
In the Employee class remove
System.out.println("employee id is"+input.readInt());
And,
new employee(input.readInt(),input.readUTF(),input.readUTF(),
input.readUTF(),input.readInt());
from,
#Override
public void readFields(DataInput input) throws IOException {
// TODO Auto-generated method stubt
System.out.println("employee id is"+input.readInt());
//this.employeeId=input.readInt();
//this.employeeName=input.readUTF();
//this.employeeDept=input.readUTF();
//this.employeeJoinDt=input.readUTF();mployee id
//this.employeeSalary=input.readInt();
new employee(input.readInt(),input.readUTF(),input.readUTF(),input.readUTF(),input.readInt());
}
Reason: The System.out.println("employee id is"+input.readInt()); already deserializes your first input and that's why using input.readInt() again is causing the issue. And the other line new Employee(....), you are possibly well aware of not using it like this. Atleast I don't do.
Next in the JobRunner class,
remove this line:
jobConf.setOutputValueClass(employee.class);
add these lines,
jobConf.setMapOutputKeyClass(Text.class);
jobConf.setMapOutputValueClass(employee.class);
jobConf.setOutputKeyClass(Text.class);
jobConf.setOutputValueClass(IntWritable.class);
Addendum: Please use capital letters to start a class name. It breaks Java naming convention, if you are not.