A discussion on Hadoop

1. Consider you are uploading a file of 300 MB into HDFS, a data of 200 MB was successfully uploaded another client simultaneously wanted to read the uploaded Data(uploading is still continuing). What incurs at this situation
                 a) Arises an exception
                 b) Data will be displayed successfully
                 c) Uploading is interrupted
                 d) The uploaded 200 MB will be displayed

2. Why should you stop all the Task Trackers while decommissioning the nodes in Hadoop cluster
                 a) To overcome the situation of Speculative execution
                 b) To avoid external interference on the new nodes
                 c) In order to make the new nodes identify for Namenode
                 d) JobTacker recieves heartbeats from new nodes only when it is restarted
3. When do your Namenode enters the safe mode
                  a) When 80% of its metadata was filled
                  b) When least replication factor was reached
                  c) Both
                  d) When edit log was full