Hortonworks HDPCD Exam Practice Test Instant Access

Question 1

You wrote a map function that throws a runtime exception when it encounters a control character in input dat

a. The input supplied to your mapper contains twelve such characters totals, spread across five file splits. The first four file splits each have two control characters and the last split has four control characters.

Indentify the number of failed task attempts you can expect when you run the job with mapred.max.map.attempts set to 4:

AYou will have forty-eight failed task attempts

BYou will have seventeen failed task attempts

CYou will have five failed task attempts

DYou will have twelve failed task attempts

EYou will have twenty failed task attempts

Answer : E

There will be four failed task attempts for each of the five file splits.

Note:

Question 2

Which one of the following statements is false about HCatalog?

AProvides a shared schema mechanism

BDesigned to be used by other programs such as Pig, Hive and MapReduce

CStores HDFS data in a database for performing SQL-like ad-hoc queries

DExists as a subproject of Hive

Answer : C

Question 3

Can you use MapReduce to perform a relational join on two large tables sharing a key? Assume that the two tables are formatted as comma-separated files in HDFS.

AYes.

BYes, but only if one of the tables fits into memory

CYes, so long as both tables fit into memory.

DNo, MapReduce cannot perform relational operations.

ENo, but it can be done with either Pig or Hive.

Answer : A

Note:

* Join Algorithms in MapReduce

A) Reduce-side join

B) Map-side join

C) In-memory join

/ Striped Striped variant variant

/ Memcached variant

* Which join to use?

/ In-memory join > map-side join > reduce-side join

/ Limitations of each?

In-memory join: memory

Map-side join: sort order and partitioning

Reduce-side join: general purpose

Question 4

Consider the following two relations, A and B.

What is the output of the following Pig commands?

X = GROUP A BY S1;

DUMP X;

AOption A

BOption B

COption C

DOption D

Answer : D

Question 5

You need to run the same job many times with minor variations. Rather than hardcoding all job configuration options in your drive code, you've decided to have your Driver subclass org.apache.hadoop.conf.Configured and implement the org.apache.hadoop.util.Tool interface.

Indentify which invocation correctly passes.mapred.job.name with a value of Example to Hadoop?

Ahadoop ''mapred.job.name=Example'' MyDriver input output

Bhadoop MyDriver mapred.job.name=Example input output

Chadoop MyDrive --D mapred.job.name=Example input output

Dhadoop setproperty mapred.job.name=Example MyDriver input output

Ehadoop setproperty (''mapred.job.name=Example'') MyDriver input output

Answer : C

Configure the property using the -D key=value notation:

-D mapred.job.name='My Job'

You can list a whole bunch of options by calling the streaming jar with just the -info argument

Question 6

To use a lava user-defined function (UDF) with Pig what must you do?

ADefine an alias to shorten the function name

BPass arguments to the constructor of UDFs implementation class

CRegister the JAR file containing the UDF

DPut the JAR file into the user's home folder in HDFS

Answer : C

Question 7

On a cluster running MapReduce v1 (MRv1), a TaskTracker heartbeats into the JobTracker on your cluster, and alerts the JobTracker it has an open map task slot.

What determines how the JobTracker assigns each map task to a TaskTracker?

AThe amount of RAM installed on the TaskTracker node.

BThe amount of free disk space on the TaskTracker node.

CThe number and speed of CPU cores on the TaskTracker node.

DThe average system load on the TaskTracker node over the past fifteen (15) minutes.

EThe location of the InsputSplit to be processed in relation to the location of the node.

Answer : E

The TaskTrackers send out heartbeat messages to the JobTracker, usually every few minutes, to reassure the JobTracker that it is still alive. These message also inform the JobTracker of the number of available slots, so the JobTracker can stay up to date with where in the cluster work can be delegated. When the JobTracker tries to find somewhere to schedule a task within the MapReduce operations, it first looks for an empty slot on the same server that hosts the DataNode containing the data, and if not, it looks for an empty slot on a machine in the same rack.

Hortonworks HDPCD Hortonworks Data Platform Certified Developer Exam Practice Test