On a cluster running CDH 5.0 or above, you use the hadoop fs -put command to write a 300MB file into a previously empty directory using an HDFS block size of 64 MB. Just after this command has finished writing 200 MB of this file, what would another use see when they look in directory?
A) The directory will appear to be empty until the entire file write is completed on the cluster
B) They will see the file with a ._COPYING_ extension on its name. If they view the file, they will see contents of the file up to the last completed block (as each 64MB block is written, that block becomes available)
C) They will see the file with a ._COPYING_ extension on its name. If they attempt to view the file, they will get a ConcurrentFileAccessException until the entire file write is completed on the cluster
D) They will see the file with its original name. If they attempt to view the file, they will get a ConcurrentFileAccessException until the entire file write is completed on the cluster

Question

Quizplus · Accepted Answer

In HDFS, when a file is being written, it is visible with a ._COPYING_ extension. As each block is completed, it becomes available for reading, so users can see the contents up to the last completed block.

On a Cluster Running CDH 5