Online Access Free CCA-470 Exam Questions

Cluster Summary
45 files and directories, 12 blocks = 57 total. Heap Size is 15.31 MB / 193.38MB(7%)

Refer to the above screenshot.
You configure the Hadoop cluster with seven DataNodes and the NameNode's web UI displays the details shown in the exhibit.
What does this tells you?

• A.Your cluster has lost all HDFS data which had blocks stored on the dead DataNode.
• B.The HDFS cluster is in the safe mode.
• C.One physical host crashed.
• D.The DataNode JVM on one host is not active.

You observe that the number of spilled records from map tasks for exceeds the number of map output records. You child heap size is 1 GB and your io.sort.mb value is set to 100MB. How would you tune your io.sort.mb value to achieve maximum memory to disk I/O ratio?

• A.Decrease the io.sort.mb value below 100M
• B.Increase the IO.sort.mb as high you can, as close to 1GB as possible.
• C.For 1GB child heap size an io.sort.mb of 128MB will always maximum memory to disk I/O.
• D.Tune io.sort.mb value until you observe that the number of spilled records equals (or is as close to equals) the number of map output records.

What is the standard configuration of slave nodes in a Hadoop cluster?

• A.Each slave node either runs a TaskTracker or a DataNode daemon, but not both.
• B.Each slave node runs a DataNode daemon, but only a fraction of the slave nodes run TaskTrackers.
• C.Each slave node runs a TaskTracker and a DataNode daemon.
• D.Each slave node runs a JobTracker and a DataNode daemon.
• E.Each slave node runs a TaskTracker, but only a fraction of the slave nodes run DataNode daemons.

Which scheduler would you deploy to ensure that your cluster allows short jobs to finish within a reasonable time without starving long-running jobs?

• A.Completely Fair Scheduler (CFS)
• B.FIFO Scheduler
• C.Capacity Scheduler
• D.Fair Scheduler

Which command does Hadoop offer to discover missing or corrupt HDFS data?

• A.Fsck
• B.Dskchk
• C.Hadoop does not provide any tools to discover missing or corrupt data; there is no need because three replicas are kept for each data block.
• D.Du
• E.The map-only checksum utility,