Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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Correct Answer: A. Many tiny files consume excessive NameNode metadata and reduce processing efficiency
Explanation:
Each file and block requires metadata in NameNode memory.
Large numbers of small files also create scheduling and I/O overhead.
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Correct Answer: D. Files are generally appended or read rather than modified at arbitrary positions
Explanation:
Avoiding random in-place updates simplifies replication and consistency.
HDFS supports appends in many deployments but not arbitrary block edits.
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Correct Answer: C. Large sequential reads and writes
Explanation:
HDFS targets high-throughput streaming access to large files.
It is not designed as a general-purpose low-latency file system.
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Correct Answer: B. Placing replicas across racks to tolerate rack or network failures
Explanation:
Failures can affect an entire rack or switch.
Cross-rack replication improves resilience while balancing network cost.
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Correct Answer: A. A list of blocks stored on a DataNode
Explanation:
Block reports help the NameNode maintain accurate block-location metadata.
They complement frequent lightweight heartbeats.
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Correct Answer: D. Evidence that the DataNode is alive and available
Explanation:
DataNodes send regular heartbeats to the NameNode.
Missing heartbeats can cause the node to be marked unavailable.
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Correct Answer: C. The NameNode schedules creation of another replica from an existing copy
Explanation:
The NameNode monitors replica counts using DataNode reports.
Under-replicated blocks are copied to restore the target factor.
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Correct Answer: B. The number of copies maintained for each block
Explanation:
Replication protects data from disk and node failures.
A common default in production clusters has historically been three.
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Correct Answer: A. A fixed-size chunk into which a file is divided
Explanation:
Files are split into blocks that can be stored on different DataNodes.
The final block may be smaller than the configured block size.
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Correct Answer: D. To reduce metadata overhead and support efficient sequential I/O
Explanation:
Large blocks reduce the number of metadata entries for huge files.
They also match high-throughput streaming access patterns.
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Correct Answer: C. The directory hierarchy and file metadata
Explanation:
The namespace represents folders, file names, ownership, permissions, and block mappings.
It is maintained by the NameNode.
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Correct Answer: B. DataNode
Explanation:
DataNodes store and serve HDFS blocks.
They also perform replication, deletion, and recovery as instructed.
