Cloudera CCA-500 Free Practice Questions 2021

NEW QUESTION 1
A slave node in your cluster has 4 TB hard drives installed (4 x 2TB). The DataNode is configured to store HDFS blocks on all disks. You set the value of the dfs.datanode.du.reserved parameter to 100 GB. How does this alter HDFS block storage?

• A. 25GB on each hard drive may not be used to store HDFS blocks
• B. 100GB on each hard drive may not be used to store HDFS blocks
• C. All hard drives may be used to store HDFS blocks as long as at least 100 GB in total is available on the node
• D. A maximum if 100 GB on each hard drive may be used to store HDFS blocks

Answer: B

NEW QUESTION 2
Your cluster has the following characteristics:
✑ A rack aware topology is configured and on
✑ Replication is set to 3
✑ Cluster block size is set to 64MB
Which describes the file read process when a client application connects into the cluster and requests a 50MB file?

• A. The client queries the NameNode for the locations of the block, and reads all three copie
• B. The first copy to complete transfer to the client is the one the client reads as part of hadoop’s speculative execution framework.
• C. The client queries the NameNode for the locations of the block, and reads from the first location in the list it receives.
• D. The client queries the NameNode for the locations of the block, and reads from a random location in the list it receives to eliminate network I/O loads by balancing which nodes it retrieves data from any given time.
• E. The client queries the NameNode which retrieves the block from the nearest DataNode to the client then passes that block back to the client.

Answer: B

NEW QUESTION 3
Your Hadoop cluster contains nodes in three racks. You have not configured the dfs.hosts property in the NameNode’s configuration file. What results?

• A. The NameNode will update the dfs.hosts property to include machines running the DataNode daemon on the next NameNode reboot or with the command dfsadmin–refreshNodes
• B. No new nodes can be added to the cluster until you specify them in the dfs.hosts file
• C. Any machine running the DataNode daemon can immediately join the cluster
• D. Presented with a blank dfs.hosts property, the NameNode will permit DataNodes specified in mapred.hosts to join the cluster

Answer: C

NEW QUESTION 4
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 5
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 6
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 7
Which YARN process run as “container 0” of a submitted job and is responsible for resource qrequests?

• A. ApplicationManager
• B. JobTracker
• C. ApplicationMaster
• D. JobHistoryServer
• E. ResoureManager
• F. NodeManager

Answer: C

NEW QUESTION 8
What does CDH packaging do on install to facilitate Kerberos security setup?

• A. Automatically configures permissions for log files at & MAPRED_LOG_DIR/userlogs
• B. Creates users for hdfs and mapreduce to facilitate role assignment
• C. Creates directories for temp, hdfs, and mapreduce with the correct permissions
• D. Creates a set of pre-configured Kerberos keytab files and their permissions
• E. Creates and configures your kdc with default cluster values

Answer: B

NEW QUESTION 9
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 10
You are configuring your cluster to run HDFS and MapReducer v2 (MRv2) on YARN. Which two daemons needs to be installed on your cluster’s master nodes?(Choose two)

• A. HMaster
• B. ResourceManager
• C. TaskManager
• D. JobTracker
• E. NameNode
• F. DataNode

Answer: BE

NEW QUESTION 11
Your cluster’s mapred-start.xml includes the following parameters
<name>mapreduce.map.memory.mb</name>
<value>4096</value>
<name>mapreduce.reduce.memory.mb</name>
<value>8192</value>
And any cluster’s yarn-site.xml includes the following parameters
<name>yarn.nodemanager.vmen-pmen-ration</name>
<value>2.1</value>
What is the maximum amount of virtual memory allocated for each map task before YARN will kill its Container?

• A. 4 GB
• B. 17.2 GB
• C. 8.9 GB
• D. 8.2 GB
• E. 24.6 GB

Answer: D

NEW QUESTION 12
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

Answer: A

NEW QUESTION 13
For each YARN job, the Hadoop framework generates task log file. Where are Hadoop task log files stored?

• A. Cached by the NodeManager managing the job containers, then written to a log directory on the NameNode
• B. Cached in the YARN container running the task, then copied into HDFS on job completion
• C. In HDFS, in the directory of the user who generates the job
• D. On the local disk of the slave mode running the task

Answer: D

NEW QUESTION 14
You are migrating a cluster from MApReduce version 1 (MRv1) to MapReduce version 2 (MRv2) on YARN. You want to maintain your MRv1 TaskTracker slot capacities when you migrate. What should you do/

• A. Configure yarn.applicationmaster.resource.memory-mb and yarn.applicationmaster.resource.cpu-vcores so that ApplicationMaster container allocations match the capacity you require.
• B. You don’t need to configure or balance these properties in YARN as YARN dynamically balances resource management capabilities on your cluster
• C. Configure mapred.tasktracker.map.tasks.maximum and mapred.tasktracker.reduce.tasks.maximum ub yarn-site.xml to match your cluster’s capacity set by the yarn-scheduler.minimum-allocation
• D. Configure yarn.nodemanager.resource.memory-mb and yarn.nodemanager.resource.cpu-vcores to match the capacity you require under YARN for each NodeManager

Answer: D

NEW QUESTION 15
You need to analyze 60,000,000 images stored in JPEG format, each of which is approximately 25 KB. Because you Hadoop cluster isn’t optimized for storing and processing many small files, you decide to do the following actions:
1. Group the individual images into a set of larger files
2. Use the set of larger files as input for a MapReduce job that processes them directly with python using Hadoop streaming.
Which data serialization system gives the flexibility to do this?

• A. CSV
• B. XML
• C. HTML
• D. Avro
• E. SequenceFiles
• F. JSON

Answer: E

Explanation: Sequence files are block-compressed and provide direct serialization and deserialization of several arbitrary data types (not just text). Sequence files can be generated as the output of other MapReduce tasks and are an efficient intermediate representation for data that is passing from one MapReduce job to anther.

NEW QUESTION 16
You have installed a cluster HDFS and MapReduce version 2 (MRv2) on YARN. You have no dfs.hosts entry(ies) in your hdfs-site.xml configuration file. You configure a new worker node by setting fs.default.name in its configuration files to point to the NameNode on your cluster, and you start the DataNode daemon on that worker node. What do you have to do on the cluster to allow the worker node to join, and start sorting HDFS blocks?

• A. Without creating a dfs.hosts file or making any entries, run the commands hadoop.dfsadmin-refreshModes on the NameNode
• B. Restart the NameNode
• C. Creating a dfs.hosts file on the NameNode, add the worker Node’s name to it, then issue the command hadoop dfsadmin –refresh Nodes = on the Namenode
• D. Nothing; the worker node will automatically join the cluster when NameNode daemon is started

Answer: A