I am trying Hadoop map-reduce in Linux (Ubuntu Virtual Machine) by following [the link](http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-single-node-cluster/#installation)

I ran the wordcount example on a sample file. The process gets killed unexpectedly. How can I debug this ? 

Initially I was getting an insufficient memory error on large data set. 

```
15/11/28 19:24:27 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
15/11/28 19:24:27 INFO mapred.MapTask: Processing split: hdfs://localhost:54310/user/hduser/eg2/a.txt:0+1538
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000e6093000, 104861696, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 104861696 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /usr/local/hadoop/hs_err_pid7516.log

```

So I reduced the size of my files and tried again which resulted in unexpected termination.

```
hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.0.jar  wordcount /user/hduser/eg2/ /user/hduser/eg2/eg2-output2
......
......
15/11/28 18:55:44 INFO mapred.LocalJobRunner: Waiting for map tasks
15/11/28 18:55:44 INFO mapred.LocalJobRunner: Starting task: attempt_local1996683170_0001_m_000000_0
15/11/28 18:55:44 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
15/11/28 18:55:44 INFO mapred.MapTask: Processing split: hdfs://localhost:54310/user/hduser/eg2/a.txt:0+1538
15/11/28 18:55:45 INFO mapreduce.Job: Job job_local1996683170_0001 running in uber mode : false
15/11/28 18:55:45 INFO mapreduce.Job:  map 0% reduce 0%
Killed

```

Why is the process getting terminated ?