DATABASE FUNDAMENTALS
BASICS OF BIG DATA
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Should be at least half of the primary node
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Similar to that of primary node
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Must be double of that of primary node
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Depends only on the number of data nodes it is going to handle
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Detailed explanation-1: -Namenode: We recommend at least 8GB of RAM (minimum is 2GB RAM), preferably 16GB or more.
Detailed explanation-2: -Name Node is a primary node in which all the metadata is stored into fsimage and edit log files periodically. But, when name node down secondary node will be online but this node only has the read access to the fsimage and edit log files and don’t have the write access to them.
Detailed explanation-3: -The secondary NameNode merges the fsimage and the edits log files periodically and keeps edits log size within a limit. It is usually run on a different machine than the primary NameNode since its memory requirements are on the same order as the primary NameNode.
Detailed explanation-4: -Secondary NameNode however doesn’t take over the functions of the NameNode if the NameNode encounters an issue. Secondary NameNode can be manually made the primary NameNode but it doesn’t happen automatically. Secondary NameNode is also an old concept.