TaskTracker and JobTracker don't start with start-dfs.sh in Hadoop

From hadoop version hadoop 2.0 onwards, default processing framework has been changed to YARN from Classic Mapreduce. You are using YARN, where you cannot see Jobtracker, Tasker in YARN. Jobtracker and Tasktracker is replaced by Resource manager and Nodemanager respectively in YARN.

But still you have an option to use Classic Mapreduce framework instead of YARN.