Hadoop Practice Test 1

1. What was Hadoop written in?

Java (software platform)

Lua (programming language)

Perl

Java (programming language)

2. Which of the following parameter is to collect keys and combined values?

reporter

output

key

values

3. Mapper and Reducer implementations can use the ________ to report progress or just indicate that they are alive.

Reporter

OutputCollector

All of the mentioned

Partitioner

4. Point out the wrong statement.

Reducer has 2 primary phases

Increasing the number of reduces increases the framework overhead, but increases load balancing and lowers the cost of failures

It is legal to set the number of reduce-tasks to zero if no reduction is desired

The framework groups Reducer inputs by keys (since different mappers may have output the same key) in the sort stage

5. ________ is the slave/worker node and holds the user data in the form of Data Blocks.

Replication

DataNode

NameNode

Data block

6. Above the file systems comes the ________ engine, which consists of one Job Tracker, to which client applications submit MapReduce jobs.

MapReduce

Facebook

Google

Functional programming

7. Point out the correct statement.

Pig is a relational database with SQL support

Hive is not a relational database, but a query engine that supports the parts of SQL specific to querying data

Hive is a relational database with SQL support

All of the mentioned

8. Point out the wrong statement.

User data is stored on the local file system of DataNodes

Block Report from each DataNode contains a list of all the blocks that are stored on that DataNode

DataNode is aware of the files to which the blocks stored on it belong to

Replication Factor can be configured at a cluster level (Default is set to 3) and also at a file level

9. Point out the correct statement.

You can specify any executable as the mapper and/or the reducer

All of the mentioned

The class you supply for the output format should return key/value pairs of Text class

You cannot supply a Java class as the mapper and/or the reducer

10. Input to the _______ is the sorted output of the mappers.

Mapper

Shuffle

Reducer

All of the mentioned