Q85.Marks: +2.0UGC NET Paper 2: Computer Science 2nd January 2026 Shift 1
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: HDFS follows a master-slave architecture with Name Node and Data Nodes.
Reason R: Name Node stores metadata, while Data Nodes store actual data blocks.
In the light of the above statements, choose the most appropriate answer from the options given below
1.Both A and R are correct and R is the correct explanation of A✓ Correct
2.Both A and R are correct but R is NOT the correct explanation of A
3.A is correct but R is not correct
4.A is not correct but R is correct
Solution
The correct answer is Both A and R are correct and R is the correct explanation of A.
Key Points
HDFS (Hadoop Distributed File System) follows a master-slave architecture.
The master in HDFS is the Name Node, which manages the file system namespace and metadata.
The slaves are Data Nodes, which store the actual data blocks.
The Name Node is responsible for keeping track of the structure of the file system and the location of data blocks.
The Data Nodes perform the actual storage and retrieval of blocks based on instructions from the Name Node.
Additional Information
About HDFS Architecture:
HDFS is designed for distributed storage and processing of large-scale data.
The architecture consists of a single Name Node and multiple Data Nodes.
The Name Node maintains metadata such as file structure, permissions, and locations of data blocks.
The Data Nodes store and manage the blocks of data, ensuring redundancy and fault tolerance.
Role of Metadata in HDFS:
Metadata includes the structure of the file system, file names, directory structure, and file permissions.
It is stored in the Name Node and is critical for the operation of HDFS.
Regular backups of metadata are maintained to prevent data loss.
Data Block Management:
Files in HDFS are divided into blocks, typically of 128MB or 256MB size.
Blocks are replicated across Data Nodes to ensure fault tolerance and high availability.
The default replication factor in HDFS is 3, meaning each block is stored on three different Data Nodes.
Advantages of HDFS:
Scalability: Can handle large datasets across distributed systems.
Fault Tolerance: Data replication ensures resilience against node failures.
High Throughput: Optimized for reading and writing large files efficiently.
Cost-effective: Utilizes commodity hardware for storage and processing.
