DATABASE FUNDAMENTALS
BASICS OF BIG DATA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Rack
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Data
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Secondary
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None of the mentioned
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Detailed explanation-1: -NameNode is used when the Primary NameNode goes down. Explanation: Secondary namenode is used for all time availability and reliability.
Detailed explanation-2: -NameNode is used when the Primary NameNode goes down. Answer : Standby.
Detailed explanation-3: -When the NameNode goes down, the file system goes offline. There is an optional SecondaryNameNode that can be hosted on a separate machine. It only creates checkpoints of the namespace by merging the edits file into the fsimage file and does not provide any real redundancy.
Detailed explanation-4: -NameNode is the master node in the Apache Hadoop HDFS Architecture that maintains and manages the blocks present on the DataNodes (slave nodes). NameNode is a very highly available server that manages the File System Namespace and controls access to files by clients.
Detailed explanation-5: -The main function of the Secondary namenode is to store the latest copy of the FsImage and the Edits Log files. How does it help? When the namenode is restarted, the latest copies of the Edits Log files are applied to the FsImage file in order to keep the HDFS metadata latest.