Hello Shahil, In the current trunk codebase, the relevant files are hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-co re/src/main/java/org/apache/hadoop/mapred/MapTask.java and hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-co re/src/main/java/org/apache/hadoop/mapreduce/Mapper.java. MapTask manages the execution of the mapper task, and eventually it calls Mapper#run, which then calls into the implementation of the map method. BTW, you'll also see a corresponding ReduceTask.java and Reducer.java in the same directories if you need to look at those too.
Input split calculation is performed by a subclass of InputFormat. http://hadoop.apache.org/docs/r2.6.0/api/org/apache/hadoop/mapreduce/InputF ormat.html I recommend looking at that. You also can navigate down through those JavaDocs to identify subclasses of InputFormat, like FileInputFormat and TextInputFormat, which you can then find in the source code. I hope this helps. Chris Nauroth Hortonworks http://hortonworks.com/ On 4/7/15, 6:09 AM, "Shahil Varshney" <shahilvarsh...@gmail.com> wrote: >Sir , >i want to know that which class in hadoop (internal source class) is >responsible for calling map function for each key value pair(means calls >map() function). > > and which class actually done the input split job. i want to create my >own >class for input split so please tell me .
