CCA-410 · Question #57
Once a client application validates its identity and is granted access to file in a cluster. What is the reminder of read path back to the client?
The correct answer is A. The namenode gives the client the block ID's and a list of Datanodes on which those blocks are found. Here is how a client RPC request to the Hadoop HDFS NameNode flows through the NameNode. The Hadoop NameNode receives requests from HDFS clients in the form of Hadoop RPC requests over a TCP connection. Typical client requests include mkdir, getBlockLocations, create file, etc…
Question
Once a client application validates its identity and is granted access to file in a cluster. What is the reminder of read path back to the client?
Options
- AThe namenode gives the client the block ID's and a list of Datanodes on which those blocks are found.
- Bthe namenode maps the read request against the block locations in its stored metadata and reads those
- CThe namenode maps the read request against the block locations in it's stored metadata the block id's
How the community answered
(39 responses)- A82% (32)
- B13% (5)
- C5% (2)
Explanation
Here is how a client RPC request to the Hadoop HDFS NameNode flows through the NameNode. The Hadoop NameNode receives requests from HDFS clients in the form of Hadoop RPC requests over a TCP connection. Typical client requests include mkdir, getBlockLocations, create file, etc. Remember - HDFS separates metadata from actual file data, and that the NameNode is the metadata server. Hence, these requests are pure metadata requests - no data transfer is
Topics
Community Discussion
No community discussion yet for this question.