is there any parallelism in single node hadoop?

Question

i'm newer in hadoop. and i could run mahout example in single node hadoop. is there any parallelism in single node hadoop? (for example in jobs, chunks, ) (hadoop works faster than WEKA in my workload)

Answer 1

The mode you are referring to is same as pseudo-distributed mode. This is a one node cluster. In this you have a namenode, a jobtracker, and a single datanode and tasktracker running. You can verify with "jps" command.

By default a tasktracker can run up to two map and reduce tasks in parallel (mapred.tasktracker.map.tasks.maximum and mapred.tasktracker.reduce.tasks.maximum), so you will actually see some concurrency on your one machine.