UNIT-3

Which of the following is responsible for managing the metadata of HDFS?

• DataNode

• TaskTracker

• NameNode

• JobTracker

What is the role of the Secondary NameNode (SNN) in Hadoop?

• It serves as a backup for NameNode.

• It helps in periodic checkpointing of NameNode metadata.

• It processes client requests.

• It assigns tasks to TaskTrackers.

Which process in Hadoop is responsible for executing tasks assigned by the JobTracker?

• TaskTracker

• JobTracker

• NameNode

• Secondary NameNode

Which common error occurs when the Hadoop temporary directory is not properly set?

• java.io.IOException: No space left on device

• NameNode not responding

• JobTracker failure

• TaskTracker timeout

How can you resolve a missing Hadoop temporary directory error?

• Restart the TaskTracker.

• Set the correct hadoop.tmp.dir path in core-site.xml.

• Increase heap size in hadoop-env.sh.

• Disable Safe Mode.

Which command is used to install Java, a prerequisite for Hadoop, on Ubuntu?

• sudo apt install hadoop

• sudo apt install openjdk-8-jdk

• hadoop version

• sudo install hdfs

Why is SSH required when setting up Hadoop?

• It allows Hadoop processes to communicate.

• It is needed for web UI access.

• It helps in secure client connections.

• It is not required for Hadoop.

Which command initializes the Hadoop Distributed File System (HDFS) for the first time?

• hadoop namenode -start

• hdfs namenode -format

• hadoop fs -ls /

• hdfs namenode -restart

What is the default replication factor in HDFS?

• 1

• 2

• 3

• 5

What are the key components of a MapReduce job?

• NameNode and DataNode

• Map function and Reduce function

• JobTracker and TaskTracker

• Hive and Pig