Tag: Hadoop HDFS

Excellent ! Your Answer is Correct. Explanation: If the NameNode machine fails, manual intervention is necessary. Currently, automatic restart and failover of the NameNode software to another machine is not supported.

Excellent ! Your Answer is Correct. Explanation: A scheme might automatically move data from one DataNode to another if the free space on a DataNode falls below a certain threshold.

Excellent ! Your Answer is Correct. Explanation: When a client creates an HDFS file, it computes a checksum of each block of the file and stores these checksums in a separate hidden file in the same HDFS namespace.

Excellent ! Your Answer is Correct. In the phase the framework, for each Reducer, fetches the relevant partition of the output of all the Mappers, via HTTP.

Excellent ! Your Answer is Correct. Reducer implementations can access the JobConf for the job.

Excellent ! Your Answer is Correct. A DataNode stores data in the [HadoopFileSystem]. A functional filesystem has more than one DataNode, with data replicated across them.

Excellent ! Your Answer is Correct. Data is replicated across different DataNodes to ensure a high degree of fault-tolerance.

Excellent ! Your Answer is Correct. identifies destination directory which would contain the archive.