MapReduce makes the guarantee that the input to every reducer is sorted by key. The process by which the system…
Performance issues in a map reduce jobs is a common problem faced by hadoop developers and there are a few hadoop…
Sequence files, map files, and Avro datafiles are all row-oriented file formats, which means that the values for each row…
Serialization is the process of turning structured objects into a byte stream for transmission over a network or for writing…
File compression brings two major benefits: it reduces the space needed to store files, and it speeds up data transfer…
HDFS transparently checksums all data written to it and by default verifies checksums when reading data. Datanodes are responsible for…
Apache YARN (Yet Another Resource Negotiator) is Hadoop’s cluster resource management system. YARN was introduced in Hadoop 2 to improve…