NEW QUESTION 1
In CDH4 and later, which file contains a serialized form of all the directory and files inodes in the filesystem, giving the NameNode a persistent checkpoint of the filesystem metadata?

• A. fstime
• B. VERSION
• C. Fsimage_N (where N reflects transactions up to transaction ID N)
• D. Edits_N-M (where N-M transactions between transaction ID N and transaction ID N)

Answer: C

Explanation: Reference:http://mikepluta.com/tag/namenode/

NEW QUESTION 2
You’re upgrading a Hadoop cluster from HDFS and MapReduce version 1 (MRv1) to one running HDFS and MapReduce version 2 (MRv2) on YARN. You want to set and enforce version 1 (MRv1) to one running HDFS and MapReduce version 2 (MRv2) on YARN. You want to set and enforce a block size of 128MB for all new files written to the cluster after upgrade. What should you do?

• A. You cannot enforce this, since client code can always override this value
• B. Set dfs.block.size to 128M on all the worker nodes, on all client machines, and on the NameNode, and set the parameter to final
• C. Set dfs.block.size to 128 M on all the worker nodes and client machines, and set the parameter to fina
• D. You do not need to set this value on the NameNode
• E. Set dfs.block.size to 134217728 on all the worker nodes, on all client machines, and on the NameNode, and set the parameter to final
• F. Set dfs.block.size to 134217728 on all the worker nodes and client machines, and set the parameter to fina
• G. You do not need to set this value on the NameNode

Answer: C

NEW QUESTION 3
Which scheduler would you deploy to ensure that your cluster allows short jobs to finish within a reasonable time without starting long-running jobs?

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

Answer: C

Explanation: Reference:http://hadoop.apache.org/docs/r1.2.1/fair_scheduler.html

NEW QUESTION 4
Which two are features of Hadoop’s rack topology?(Choose two)

• A. Configuration of rack awareness is accomplished using a configuration fil
• B. You cannot use a rack topology script.
• C. Hadoop gives preference to intra-rack data transfer in order to conserve bandwidth
• D. Rack location is considered in the HDFS block placement policy
• E. HDFS is rack aware but MapReduce daemon are not
• F. Even for small clusters on a single rack, configuring rack awareness will improve performance

Answer: BC

NEW QUESTION 5
You are running a Hadoop cluster with MapReduce version 2 (MRv2) on YARN. You consistently see that MapReduce map tasks on your cluster are running slowly because of excessive garbage collection of JVM, how do you increase JVM heap size property to 3GB to optimize performance?

• A. yarn.application.child.java.opts=-Xsx3072m
• B. yarn.application.child.java.opts=-Xmx3072m
• C. mapreduce.map.java.opts=-Xms3072m
• D. mapreduce.map.java.opts=-Xmx3072m

Answer: C

Explanation: Reference:http://hortonworks.com/blog/how-to-plan-and-configure-yarn-in-hdp-2-0/

NEW QUESTION 6
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 replicationfactor 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. 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)
• C. This will be immediately re-replicated and all other HDFS operations on the cluster will halt until the cluster’s replication values are resorted
• 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

Answer: D

NEW QUESTION 7
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

Answer: A

Explanation: http://wiki.apache.org/hadoop/FAQ#I_have_a_new_node_I_want_to_add_to_a_running_H adoop_cluster.3B_how_do_I_start_services_on_just_one_node.3F

NEW QUESTION 8
Your company stores user profile records in an OLTP databases. You want to join these records with web server logs you have already ingested into the Hadoop file system. What is the best way to obtain and ingest these user records?

• A. Ingest with Hadoop streaming
• B. Ingest using Hive’s IQAD DATA command
• C. Ingest with sqoop import
• D. Ingest with Pig’s LOAD command
• E. Ingest using the HDFS put command

Answer: C

NEW QUESTION 9
Your cluster implements HDFS High Availability (HA). Your two NameNodes are named nn01 and nn02. What occurs when you execute the command: hdfs haadmin –failover nn01 nn02?

• A. nn02 is fenced, and nn01 becomes the active NameNode
• B. nn01 is fenced, and nn02 becomes the active NameNode
• C. nn01 becomes the standby NameNode and nn02 becomes the active NameNode
• D. nn02 becomes the standby NameNode and nn01 becomes the active NameNode

Answer: B

Explanation: failover – initiate a failover between two NameNodes
This subcommand causes a failover from the first provided NameNode to the second. If the first
NameNode is in the Standby state, this command simply transitions the second to the Active statewithout error. If the first NameNode is in the Active state, an attempt will be made to gracefullytransition it to the Standby state. If this fails, the fencing methods (as configured bydfs.ha.fencing.methods) will be attempted in order until one of the methods succeeds. Only afterthis process will the second NameNode be transitioned to the Active state. If no fencing methodsucceeds, the second NameNode will not be transitioned to the Active state, and an error will bereturned.

NEW QUESTION 10
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

Answer: A

NEW QUESTION 11
Which YARN daemon or service monitors a Controller’s per-application resource using (e.g., memory CPU)?

• A. ApplicationMaster
• B. NodeManager
• C. ApplicationManagerService
• D. ResourceManager

Answer: A

NEW QUESTION 12
You are running a Hadoop cluster with a NameNode on host mynamenode. What are two ways to determine available HDFS space in your cluster?

• A. Run hdfs fs –du / and locate the DFS Remaining value
• B. Run hdfs dfsadmin –report and locate the DFS Remaining value
• C. Run hdfs dfs / and subtract NDFS Used from configured Capacity
• D. Connect to http://mynamenode:50070/dfshealth.jsp and locate the DFS remaining value

Answer: B

NEW QUESTION 13
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

Answer: A

NEW QUESTION 14
You are running Hadoop cluster with all monitoring facilities properly configured. Which scenario will go undeselected?

• A. HDFS is almost full
• B. The NameNode goes down
• C. A DataNode is disconnected from the cluster
• D. Map or reduce tasks that are stuck in an infinite loop
• E. MapReduce jobs are causing excessive memory swaps

Answer: B

NEW QUESTION 15
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 nam
• C. 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)
• D. They will see the file with a ._COPYING_ extension on its nam
• E. If they attempt to view the file, they will get a ConcurrentFileAccessException until the entire file write is completed on the cluster
• F. They will see the file with its original nam
• G. If they attempt to view the file, they will get a ConcurrentFileAccessException until the entire file write is completed on the cluster

Answer: B

NEW QUESTION 16
Which three basic configuration parameters must you set to migrate your cluster from MapReduce 1 (MRv1) to MapReduce V2 (MRv2)?(Choose three)

• A. Configure the NodeManager to enable MapReduce services on YARN by setting the following property in yarn-site.xml:<name>yarn.nodemanager.hostname</name><value>your_nodeManager_shuffle</value>
• B. Configure the NodeManager hostname and enable node services on YARN by setting the following property in yarn-site.xml:<name>yarn.nodemanager.hostname</name><value>your_nodeManager_hostname</value>
• C. Configure a default scheduler to run on YARN by setting the following property in mapred-site.xml:<name>mapreduce.jobtracker.taskScheduler</name><Value>org.apache.hadoop.mapred.JobQueueTaskScheduler</value>
• D. Configure the number of map tasks per jon YARN by setting the following property in mapred:<name>mapreduce.job.maps</name><value>2</value>
• E. Configure the ResourceManager hostname and enable node services on YARN by setting the following property in yarn-site.xml:<name>yarn.resourcemanager.hostname</name><value>your_resourceManager_hostname</value>
• F. Configure MapReduce as a Framework running on YARN by setting the following property in mapred-site.xml:<name>mapreduce.framework.name</name><value>yarn</value>

Answer: AEF

NEW QUESTION 17
Assuming you’re not running HDFS Federation, what is the maximum number of NameNode daemons you should run on your cluster in order to avoid a “split-brain” scenario with your NameNode when running HDFS High Availability (HA) using Quorum- based storage?

• A. Two active NameNodes and two Standby NameNodes
• B. One active NameNode and one Standby NameNode
• C. Two active NameNodes and on Standby NameNode
• D. Unlimite
• E. HDFS High Availability (HA) is designed to overcome limitations on the number of NameNodes you can deploy

Answer: B