The data node is the working node of HDFS. What are its functions described below? (Multiple choice)

Question

Options

• AResponsible for data storage and reading
• BStore and retrieve data according to the scheduling of the client or the name node
• CRecords all operations on file creation, deletion, renaming, etc.
• DPeriodically send the name node a list of the blocks it stores.

• A
  82% (32)
• C
  18% (7)

Explanation

A, B, and D all correctly describe Data Node responsibilities in HDFS. Data Nodes are the workhorses of the distributed filesystem: they physically store block data on local disk (A), serve or write that data when directed by either the client directly or the NameNode (B), and send periodic block reports (heartbeats) to the NameNode so it knows which blocks each node holds (D).

Option C is wrong because recording file operations like creation, deletion, and renaming is the job of the NameNode, not the Data Node. The NameNode maintains the filesystem namespace and edit log (a journal of all metadata changes) - Data Nodes have no awareness of filenames or directory structure at all.

Memory tip: Think of HDFS like a library system - the NameNode is the card catalog (tracks what exists and where), while Data Nodes are the shelves (hold the actual books and report their inventory). Anything involving names or metadata = NameNode; anything involving bytes on disk = Data Node.

No community discussion yet for this question.