While taking up the Developing Hadoop Applications - DEV 301, came across two MapR features.
One is "ExpressLane", which is used for preventing the starvation of the small jobs. In this, there mentioned a slot called 'ephemeral slot' which is used when there are no available slots on the taskt racker. What is this ephemeral slot and how it is allocated in the task tracker?
Another one is "Direct Shuffle". What is the use of Direct Shuffle. Will it be used for storing the intermediate results of map tasks like in HDFS or it is used for some other purpose ? what does non local boot disk mean for its storage ?