Technical Interview Questions
These are the main tasks of JobTracker: To accept jobs from the client. To communicate with the NameNode to determine the location of the data. To locate TaskTracker Nodes with available slots. To submit the work to the chosen TaskTracker node and monitors the progress of each task. In Hadoop MapReduce, the JobTracker is a … Read more
Sqoop is a tool used to transfer data between the Relational Database Management System (RDBMS) and Hadoop HDFS. By using Sqoop, you can transfer data from RDBMS like MySQL or Oracle into HDFS as well as exporting data from HDFS file to RDBMS. Sqoop (SQL-to-Hadoop) is a tool designed for efficiently transferring bulk data between … Read more
WebDAV is a set of extension to HTTP which is used to support editing and uploading files. On most operating system WebDAV shares can be mounted as filesystems, so it is possible to access HDFS as a standard filesystem by exposing HDFS over WebDAV. WebDAV, which stands for Web Distributed Authoring and Versioning, is not … Read more
JobTracker is a service within Hadoop which runs MapReduce jobs on the cluster. In Hadoop, JobTracker was a critical component in the earlier versions (Hadoop 1.x), but it has been deprecated in favor of the ResourceManager in Hadoop 2.x and later versions. In Hadoop 1.x: JobTracker: It was a daemon that managed and monitored MapReduce … Read more
InputSplit is assigned with a work but doesn’t know how to access it. The record holder class is totally responsible for loading the data from its source and convert it into keys pair suitable for reading by the Mapper. The RecordReader’s instance can be defined by the Input Format. In Hadoop, a RecordReader is a … Read more