Hadoop Distributed File System (HDFS) DATA-SCIENCE-OPTIMIZE Practice Questions (Page 1)

Questions 1–5

1. 1foundation · easy

   How does HDFS detect and handle corruption of data blocks due to disk errors or network issues?

   • ABy comparing file sizes stored in the NameNode metadata
   • BBy using checksums stored alongside each block to verify data integrity during reads
   • CBy periodically reformatting all DataNodes to remove corrupted data
   • DBy relying on the client to report any data anomalies
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2. 2foundation · easy

   What is the primary role of the Secondary NameNode in an HDFS cluster?

   • ATo store the actual data blocks of files for redundancy
   • BTo periodically merge the NameNode's edit log with the fsimage to create a new checkpoint
   • CTo manage client requests for file reads and writes
   • DTo serve as a standby NameNode that takes over in case of failure
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4. 3foundation · easy

   Which HDFS shell command is used to list the contents of a directory in HDFS?

   • Ahdfs dfs -cat /path
   • Bhdfs dfs -ls /path
   • Chdfs dfs -mkdir /path
   • Dhdfs dfs -put /path
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5. 4application · medium

   An administrator runs hdfs fsck /data/important -files -blocks and sees that a block is listed as 'CORRUPT'. The block has a replication factor of 3. What should the administrator do first?

   • AWait for the NameNode to re-replicate the block from a healthy replica.
   • BDelete the file and restore it from backup.
   • CManually copy the block from another DataNode using hdfs dfs -cp.
   • DRestart the DataNode that reported the corruption.
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6. 5foundation · easy

   Which HDFS access method is best suited for a web application that needs to read files from HDFS over HTTP?

   • AJava API
   • BFUSE mount
   • CHDFS shell commands
   • DWebHDFS REST API
   Reveal Solution Discussion Select an answer first