Cloudera CCAH CCA-500 Questions & Answers

• Question 31:

  You are planning a Hadoop cluster and considering implementing 10 Gigabit Ethernet as the network fabric. Which workloads benefit the most from faster network fabric?

  A. When your workload generates a large amount of output data, significantly larger than the amount of intermediate data

  B. When your workload consumes a large amount of input data, relative to the entire capacity if HDFS

  C. When your workload consists of processor-intensive tasks

  D. When your workload generates a large amount of intermediate data, on the order of the input data itself

  Correct Answer: A

• Question 32:

  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

  Correct Answer: B

• Question 33:

  You suspect that your NameNode is incorrectly configured, and is swapping memory to disk. Which Linux commands help you to identify whether swapping is occurring? (Select all that apply)

  A. free

  B. df

  C. memcat

  D. top

  E. jps

  F. vmstat

  G. swapinfo

  Correct Answer: ADF

• Question 34:

  During the execution of a MapReduce v2 (MRv2) job on YARN, where does the Mapper place the intermediate data of each Map Task?

  A. The Mapper stores the intermediate data on the node running the Job's ApplicationMaster so that it is available to YARN ShuffleService before the data is presented to the Reducer

  B. The Mapper stores the intermediate data in HDFS on the node where the Map tasks ran in the HDFS / usercache/and(user)/apache/application_and(appid) directory for the user who ran the job

  C. The Mapper transfers the intermediate data immediately to the reducers as it is generated by the Map Task

  D. YARN holds the intermediate data in the NodeManager's memory (a container) until it is transferred to the Reducer

  E. The Mapper stores the intermediate data on the underlying filesystem of the local disk in the directories yarn.nodemanager.locak-DIFS

  Correct Answer: E

• Question 35:

  Which YARN daemon or service negotiations map and reduce Containers from the Scheduler, tracking their status and monitoring progress?

  A. NodeManager

  B. ApplicationMaster

  C. ApplicationManager

  D. ResourceManager

  Correct Answer: B

• Question 36:

  Assuming a cluster running HDFS, MapReduce version 2 (MRv2) on YARN with all settings at their default, what do you need to do when adding a new slave node to cluster?

  A. Nothing, other than ensuring that the DNS (or/etc/hosts files on all machines) contains any entry for the new node.

  B. Restart the NameNode and ResourceManager daemons and resubmit any running jobs.

  C. Add a new entry to /etc/nodes on the NameNode host.

  D. Restart the NameNode of dfs.number.of.nodes in hdfs-site.xml

  Correct Answer: A

• Question 37:

  Which two features does Kerberos security add to a Hadoop cluster? (Choose two)

  A. User authentication on all remote procedure calls (RPCs)

  B. Encryption for data during transfer between the Mappers and Reducers

  C. Encryption for data on disk ("at rest")

  D. Authentication for user access to the cluster against a central server

  E. Root access to the cluster for users hdfs and mapred but non-root access for clients

  Correct Answer: AD

• Question 38:

  You are working on a project where you need to chain together MapReduce, Pig jobs. You also need the ability to use forks, decision points, and path joins. Which ecosystem project should you use to perform these actions?

  A. Oozie

  B. ZooKeeper

  C. HBase

  D. Sqoop

  E. HUE

  Correct Answer: A

• Question 39:

  Which process instantiates user code, and executes map and reduce tasks on a cluster running MapReduce v2 (MRv2) on YARN?

  A. NodeManager

  B. ApplicationMaster

  C. TaskTracker

  D. JobTracker

  E. NameNode

  F. DataNode

  G. ResourceManager

  Correct Answer: A

• Question 40:

  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 a Hadoop cluster with seven DataNodes and on of your monitoring UIs displays the details

  shown in the exhibit.

  What does the this tell you?

  A. The DataNode JVM on one host is not active

  B. Because your under-replicated blocks count matches the Live Nodes, one node is dead, and your DFS Used % equals 0%, you can't be certain that your cluster has all the data you've written it.

  C. Your cluster has lost all HDFS data which had bocks stored on the dead DatNode

  D. The HDFS cluster is in safe mode

  Correct Answer: A