Question 1

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

Accepted Answer

A

Question 2

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

Accepted Answer

Oozie is a workflow scheduler system that allows you to manage Hadoop jobs, including MapReduce and Pig, and supports complex job workflows with forks, decision points, and path joins.

Question 3

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

Accepted Answer

The `free` command shows the amount of free and used memory in the system, including swap. The `top` command provides a real-time view of system processes and memory usage, including swap. The `vmstat` command reports information about processes, memory, paging, block IO, traps, and CPU activity, including swap usage.

Question 4

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

Accepted Answer

Kerberos provides user authentication on all RPCs and authenticates user access to the cluster against a central server.

Question 5

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

Accepted Answer

SequenceFiles are a data serialization system that allows for the storage of binary key-value pairs. This flexibility makes them ideal for storing and processing large numbers of small files, as they can be used to group the individual images into a set of larger files. Additionally, SequenceFiles can be used as input for a MapReduce job that processes them directly with python using Hadoop streaming.

Question 6

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

Accepted Answer

ResourceManager is the master daemon for YARN, and NameNode is the master daemon for HDFS.

Question 7

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

Accepted Answer

The default scheduler in YARN is the Capacity Scheduler, which is designed to allow sharing of resources in a large cluster while ensuring a certain capacity guarantee for different queues.

Question 8

What two processes must you do if you are running a Hadoop cluster with a single NameNode and six DataNodes, and you want to change a configuration parameter so that it affects all six DataNodes. (Choose two)
A) You must modify the configuration files on the NameNode only. DataNodes read their configuration from the master nodes
B) You must modify the configuration files on each of the DataNodes machines
C) You don't need to restart any daemon, as they will pick up changes automatically
D) You must restart the NameNode daemon to apply the changes to the cluster
E) You must restart all six DatNode daemon to apply the changes to the cluster

Accepted Answer

The answer of What two processes must you do if...

Question 9

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

Accepted Answer

The answer of A slave node in your cluster has...

Question 10

Identify two features/issues that YARN is designated to address: (Choose two)
A) Standardize on a single MapReduce API
B) Single point of failure in the NameNode
C) Reduce complexity of the MapReduce APIs
D) Resource pressure on the JobTracker
E) Ability to run framework other than MapReduce, such as MPI
F) HDFS latency

Accepted Answer

The answer of Identify two features/issues that YARN is designated...

Question 11

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

Accepted Answer

The Fair Scheduler is designed to allocate resources fairly among all jobs, ensuring that short jobs can finish quickly without being delayed by long-running jobs.

Question 12

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

Accepted Answer

The answer of Which process instantiates user code, and executes...

Question 13

What does CDH packaging do on install to facilitate Kerberos security setup?
A) Automatically configures permissions for log files at & MAPRED_LOG_DIR/ user logs
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

Accepted Answer

The answer of What does CDH packaging do on install...

Question 14

Your cluster is running MapReduce version 2 (MRv2) on YARN. Your ResourceManager is configured to use the FairScheduler. Now you want to configure your scheduler such that a new user on the cluster can submit jobs into their own queue application submission. Which configuration should you set?
A) You can specify new queue name when user submits a job and new queue can be created dynamically if the property yarn.scheduler.fair.allow-undecleared-pools = true
B) Yarn.scheduler.fair.user.fair-as-default-queue = false and yarn.scheduler.fair.allow-undecleared-pools = true
C) You can specify new queue name when user submits a job and new queue can be created dynamically if yarn .schedule.fair.user-as-default-queue = false
D) You can specify new queue name per application in allocations.xml file and have new jobs automatically assigned to the application queue

Accepted Answer

The property `yarn.scheduler.fair.allow-undecleared-pools = true` allows for the dynamic creation of new queues when a user submits a job with a new queue name.

Question 15

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

Accepted Answer

The answer of You are planning a Hadoop cluster and...

Question 16

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

Accepted Answer

In HDFS, when a file is being written, it is visible with a ._COPYING_ extension. As each block is completed, it becomes available for reading, so users can see the contents up to the last completed block.

Question 17

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

Accepted Answer

The answer of Which three basic configuration parameters must you...

Question 18

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

Accepted Answer

The NameNode will automatically detect the new node and add it to the cluster.

Question 19

You are running a Hadoop cluster with a NameNode on host mynamenode, a secondary NameNode on host mysecondarynamenode and several DataNodes. Which best describes how you determine when the last checkpoint happened?
A) Execute hdfs namenode -report on the command line and look at the Last Checkpoint information
B) Execute hdfs dfsadmin -saveNamespace on the command line which returns to you the last checkpoint value in fstime file
C) Connect to the web UI of the Secondary NameNode (http://mysecondary:50090/) and look at the "Last Checkpoint" information
D) Connect to the web UI of the NameNode (http://mynamenode:50070) and look at the "Last Checkpoint" information

Accepted Answer

The Secondary NameNode's web UI provides information about the last checkpoint, which is the process of merging the edit logs with the current file system image.

Question 20

Your cluster is configured with HDFS and MapReduce version 2 (MRv2) on YARN. What is the result when you execute: hadoop jar SampleJar MyClass on a client machine?
A) SampleJar.Jar is sent to the ApplicationMaster which allocates a container for SampleJar.Jar
B) Sample.jar is placed in a temporary directory in HDFS
C) SampleJar.jar is sent directly to the ResourceManager
D) SampleJar.jar is serialized into an XML file which is submitted to the ApplicatoionMaster

Accepted Answer

The ApplicationMaster is responsible for managing the execution of the application, and it allocates a container for the application to run.

Exam 1: Cloudera Certified Administrator for Apache Hadoop (CCAH)

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?

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)

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

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)

Which is the default scheduler in YARN?

What two processes must you do if you are running a Hadoop cluster with a single NameNode and six DataNodes, and you want to change a configuration parameter so that it affects all six DataNodes. (Choose two)

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?

Identify two features/issues that YARN is designated to address: (Choose two)

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

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

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

Your cluster is running MapReduce version 2 (MRv2) on YARN. Your ResourceManager is configured to use the FairScheduler. Now you want to configure your scheduler such that a new user on the cluster can submit jobs into their own queue application submission. Which configuration should you set?

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?

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?

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

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?

You are running a Hadoop cluster with a NameNode on host mynamenode, a secondary NameNode on host mysecondarynamenode and several DataNodes. Which best describes how you determine when the last checkpoint happened?

Your cluster is configured with HDFS and MapReduce version 2 (MRv2) on YARN. What is the result when you execute: hadoop jar SampleJar MyClass on a client machine?