Online Access Free CCA-500 Exam Questions

Choose three reasons why should you run the HDFS balancer periodically?

• A.To help HDFS deliver consistent performance under heavy loads
• B.To ensure that all blocks in the cluster are 128MB in size
• C.To improve data locality MapReduce
• D.To ensure that there is capacity in HDFS for additional data
• E.To ensure that there is consistent disk utilization across the DataNodes

You have a cluster running with a FIFO scheduler enabled. You submit a large job A to the cluster, which you expect to
run for one hour. Then, you submit job B to the cluster, which you expect to run a couple of minutes only.
You submit both jobs with the same priority.
Which two best describes how FIFO Scheduler arbitrates the cluster resources for job and its tasks?

• A.The order of execution of job may vary
• B.The FIFO Scheduler will pass an exception back to the client when Job B is submitted, since all slots on the cluster
  are use
• C.The FIFO Scheduler will give, on average, and equal share of the cluster resources over the job lifecycle
• D.Because there is a more than a single job on the cluster, the FIFO Scheduler will enforce a limit on the percentage of
  resources allocated to a particular job at any given time
• E.Tasks are scheduled on the order of their job submission
• F.Given job A and submitted in that order, all tasks from job A are guaranteed to finish before all tasks from job B

Which is the default scheduler in YARN?

• A.FIFO Scheduler
• B.YARN doesn't configure a default scheduler, you must first assign an appropriate scheduler class in yarn-site.xml
• C.Capacity Scheduler
• D.Fair Scheduler

You have just run a MapReduce job to filter user messages to only those of a selected geographical region. The output
for this job is in a directory named westUsers, located just below your home directory in HDFS. Which command
gathers these into a single file on your local file system?

• A.Hadoop fs -getemerge westUsers westUsers.txt
• B.Hadoop fs -cp westUsers/* westUsers.txt
• C.Hadoop fs -getmerge -R westUsers.txt
• D.Hadoop fs -get westUsers westUsers.txt

You use the hadoop fs -put command to add a file "sales.txt" to HDFS. This file is small enough that it fits into a single
block, which is replicated to three nodes in your cluster (with a replication factor of 3). One of the nodes holding this
file (a single block) fails. How will the cluster handle the replication of file in this situation?

• A.The file will remain under-replicated until the administrator brings that node back online
• B.This will be immediately re-replicated and all other HDFS operations on the cluster will halt until the cluster's
  replication values are resorted
• C.The cluster will re-replicate the file the next time the system administrator reboots the NameNode daemon (as long
  as the file's replication factor doesn't fall below)
• D.The file will be re-replicated automatically after the NameNode determines it is under-replicated based on the
  block reports it receives from the NameNodes