Your cluster has the following characteristics:
A rack aware topology is configured and on
Replication is set to 3
Cluster block size is set to 64MB
Which describes the file read process when a client application connects into the cluster and
requests a 50MB file?
A.
The client queries the NameNode for the locations of the block, and reads all three copies. The
first copy to complete transfer to the client is the one the client reads as part of hadoop’s
speculative execution framework.
B.
The client queries the NameNode for the locations of the block, and reads from the first location
in the list it receives.
C.
The client queries the NameNode for the locations of the block, and reads from a random
location in the list it receives to eliminate network I/O loads by balancing which nodes it retrieves
data from any given time.
D.
The client queries the NameNode which retrieves the block from the nearest DataNode to the
client then passes that block back to the client.