title: "Java Heap space Out Of Memory Error" while running a mapreduce program
body: <p>I'm facing Out Of Memory error while running a mapreduce program.If I keep 260 files in one folder and give as input to the mapreduce program,it is showing Java Heap space Out of Memory error.If I give only 100 files as input the mapreduce,it is running fine.Then how can I limit the mapreduce program to take only 100 files (~50MB) at a time. Can anyone please suggest on this issue ...</p>
  
  <p>No of files:318 ,No of blocks:1(blocksize:128MB), Hadoop is running on 32 bit system</p>
  
  <pre><code>My StackTrace:
  ==============
      15/05/05 11:52:47 INFO input.FileInputFormat: Total input paths to process : 318
      15/05/05 11:52:47 INFO input.CombineFileInputFormat: DEBUG: Terminated node allocation with : CompletedNodes: 1, size left: 52027734
      15/05/05 11:52:47 INFO mapreduce.JobSubmitter: number of splits:1
      15/05/05 11:52:47 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_local634564612_0001
      15/05/05 11:52:47 WARN conf.Configuration: file:/app/hadoop/tmp/mapred/staging/raghuveer634564612/.staging/job_local634564612_0001/job.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.
      15/05/05 11:52:47 WARN conf.Configuration: file:/app/hadoop/tmp/mapred/staging/raghuveer634564612/.staging/job_local634564612_0001/job.xml:an attempt to override final parameter: mapreduce.job.
  end-notification.max.attempts;  Ignoring.
      15/05/05 11:52:48 WARN conf.Configuration: file:/var/hadoop/mapreduce/localRunner/raghuveer/job_local634564612_0001/job_local634564612_0001.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.
      15/05/05 11:52:48 WARN conf.Configuration: file:/var/hadoop/mapreduce/localRunner/raghuveer/job_local634564612_0001/job_local634564612_0001.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.attempts;  Ignoring.
      15/05/05 11:52:48 INFO mapreduce.Job: The url to track the job: http://localhost:8080/
      15/05/05 11:52:48 INFO mapreduce.Job: Running job: job_local634564612_0001
      15/05/05 11:52:48 INFO mapred.LocalJobRunner: OutputCommitter set in config null
      15/05/05 11:52:48 INFO mapred.LocalJobRunner: OutputCommitter is org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter
      15/05/05 11:52:48 INFO mapred.LocalJobRunner: Waiting for map tasks
      15/05/05 11:52:48 INFO mapred.LocalJobRunner: Starting task: attempt_local634564612_0001_m_000000_0
      15/05/05 11:52:48 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
      15/05/05 11:52:48 INFO mapred.MapTask: Processing split: Paths:/user/usr/local/upload/20120713T07-45-42.682358000Z_79.150.138.86-1412.c2s_ndttrace:0+78550,/user/usr/local/upload/20120713T07-45-43.356723000Z_151.40.240.66-53426.c2s_ndttrace:0+32768,/user/usr/local/upload/20120713T07-45-43.718556000Z_85.26.235.102-25300.c2s_ndttrace:0+10130,/user/usr/local/upload
           .....
           .....
           .....
  /20120713T08-33-41.259331000Z_84.122.129.103-61321.c2s_ndttrace:0+19148,/user/usr/local/upload/20120713T08-33-54.972649000Z_86.69.144.214-49599.c2s_ndttrace:0+63014,/user/usr/local/upload/20120713T08-33-56.162340000Z_41.143.91.156-50785.c2s_ndttrace:0+13658,/user/usr/local/upload/20120713T08-33-59.768261000Z_31.187.12.141-50274.c2s_ndttrace:0+126542,/user/usr/local/upload/20120713T08-34-03.950055000Z_78.119.172.109-51495.c2s_ndttrace:0+92676,/user/usr/local/upload/20120713T08-34-08.378534000Z_87.7.113.115-62238.c2s_ndttrace:0+49410,/user/usr/local/upload/20120713T08-34-26.258570000Z_151.13.227.66-33198.c2s_ndttrace:0+2666092
      15/05/05 11:52:49 INFO mapreduce.Job: Job job_local634564612_0001 running in uber mode : false
      15/05/05 11:52:49 INFO mapreduce.Job:  map 0% reduce 0%
      15/05/05 11:52:50 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
      15/05/05 11:52:53 INFO mapred.MapTask: (EQUATOR) 0 kvi 78643196(314572784)
      15/05/05 11:52:53 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 300
      15/05/05 11:52:53 INFO mapred.MapTask: soft limit at 251658240
      15/05/05 11:52:53 INFO mapred.MapTask: bufstart = 0; bufvoid = 314572800
      15/05/05 11:52:53 INFO mapred.MapTask: kvstart = 78643196; length = 19660800
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (82) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (82) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:54 WARN pcap.PcapReader: Payload start (74) is larger than packet data (68). Returning empty payload.
      15/05/05 11:52:55 INFO mapred.MapTask: Starting flush of map output
      15/05/05 11:52:55 INFO mapred.MapTask: Spilling map output
      15/05/05 11:52:55 INFO mapred.MapTask: bufstart = 0; bufend = 105296; bufvoid = 314572800
      15/05/05 11:52:55 INFO mapred.MapTask: kvstart = 78643196(314572784); kvend = 78637988(314551952); length = 5209/19660800
      15/05/05 11:52:55 INFO mapred.LocalJobRunner: map &gt; map
      15/05/05 11:52:55 INFO mapred.MapTask: Finished spill 0
      15/05/05 11:52:55 INFO mapred.LocalJobRunner: map task executor complete.
      15/05/05 11:52:55 WARN mapred.LocalJobRunner: job_local634564612_0001
      java.lang.Exception: java.lang.OutOfMemoryError: Java heap space
          at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
          at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522)
      Caused by: java.lang.OutOfMemoryError: Java heap space
          at net.ripe.hadoop.pcap.PcapReader.nextPacket(PcapReader.java:208)
          at net.ripe.hadoop.pcap.PcapReader.access$0(PcapReader.java:173)
          at net.ripe.hadoop.pcap.PcapReader$PacketIterator.fetchNext(PcapReader.java:554)
          at net.ripe.hadoop.pcap.PcapReader$PacketIterator.hasNext(PcapReader.java:559)
          at net.ripe.hadoop.pcap.io.reader.PcapRecordReader.nextKeyValue(PcapRecordReader.java:57)
          at net.ripe.hadoop.pcap.io.reader.CombineBinaryRecordReader.nextKeyValue(CombineBinaryRecordReader.java:42)
          at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.nextKeyValue(CombineFileRecordReader.java:69)
          at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:533)
          at org.apache.hadoop.mapreduce.task.MapContextImpl.nextKeyValue(MapContextImpl.java:80)
          at org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.nextKeyValue(WrappedMapper.java:91)
          at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
          at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
          at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340)
          at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
          at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
          at java.util.concurrent.FutureTask.run(FutureTask.java:266)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:745)
      15/05/05 11:52:56 INFO mapreduce.Job: Job job_local634564612_0001 failed with state FAILED due to: NA
      15/05/05 11:52:56 INFO mapreduce.Job: Counters: 25
          File System Counters
              FILE: Number of bytes read=29002348
              FILE: Number of bytes written=29450636
              FILE: Number of read operations=0
              FILE: Number of large read operations=0
              FILE: Number of write operations=0
              HDFS: Number of bytes read=103142
              HDFS: Number of bytes written=0
              HDFS: Number of read operations=6
              HDFS: Number of large read operations=0
              HDFS: Number of write operations=1
          Map-Reduce Framework
              Map input records=1303
              Map output records=1303
              Map output bytes=105296
              Map output materialized bytes=0
              Input split bytes=38078
              Combine input records=0
              Spilled Records=0
              Failed Shuffles=0
              Merged Map outputs=0
              GC time elapsed (ms)=593
              CPU time spent (ms)=0
              Physical memory (bytes) snapshot=0
              Virtual memory (bytes) snapshot=0
              Total committed heap usage (bytes)=1745092608
          File Input Format Counters 
              Bytes Read=0
  </code></pre>