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?

1. A. Hadoop fs –getmerge –R westUsers.txt
2. B. Hadoop fs –getemerge westUsers westUsers.txt
3. C. Hadoop fs –cp westUsers/* westUsers.txt
4. D. Hadoop fs –get westUsers westUsers.txt

Correct Answer: B

Given:

You want to clean up this list by removing jobs where the State is KILLED. What command you enter?

1. A. Yarn application –refreshJobHistory
2. B. Yarn application –kill application_1374638600275_0109
3. C. Yarn rmadmin –refreshQueue
4. D. Yarn rmadmin –kill application_1374638600275_0109

Correct Answer: B
Reference:http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.1-latest/bk_using-apache-hadoop/content/common_mrv2_commands.html

You decide to create a cluster which runs HDFS in High Availability mode with automatic failover, using Quorum Storage. What is the purpose of ZooKeeper in such a configuration?

1. A. It only keeps track of which NameNode is Active at any given time
2. B. It monitors an NFS mount point and reports if the mount point disappears
3. C. It both keeps track of which NameNode is Active at any given time, and manages the Edits fil
4. D. Which is a log of changes to the HDFS filesystem
5. E. If only manages the Edits file, which is log of changes to the HDFS filesystem
6. F. Clients connect to ZooKeeper to determine which NameNode is Active

Correct Answer: A
Reference: Reference:http://www.cloudera.com/content/cloudera-content/cloudera-docs/CDH4/latest/PDF/CDH4-High-Availability-Guide.pdf(page 15)

Which YARN process run as “container 0” of a submitted job and is responsible for resource qrequests?

1. A. ApplicationManager
2. B. JobTracker
3. C. ApplicationMaster
4. D. JobHistoryServer
5. E. ResoureManager
6. F. NodeManager

Correct Answer: C

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?

1. A. When your workload generates a large amount of output data, significantly larger than the amount of intermediate data
2. B. When your workload consumes a large amount of input data, relative to the entire capacity if HDFS
3. C. When your workload consists of processor-intensive tasks
4. D. When your workload generates a large amount of intermediate data, on the order of the input data itself

Correct Answer: A