Hi, I am new to Hadoop and *I am interested in finding the code where the reduce and map tasks are spawn*. Towards this goal I have been going through the MapReduce, YARN source code for the past few days. I have started from the NodeManager class and found it launches containers on the corresponding node. MRAppMaster class is run by the launch_container.sh script downloaded on each of the nodes. I have observed that statemachines are used for the transition of a job, task and each of these transitions affect the state of the object. But I haven't really found a specific location in the code base where the map and reduce tasks are spawn. Any help in this regard is much appreciated.
Thanks, Sandeep
