Answer / Rajesh Kumar Saroj

High availability of a Namenode in Apache HDFS (Hadoop Distributed File System) refers to the ability to ensure continuous accessibility and uninterrupted operation of the system, even during hardware or software failures. This is primarily achieved through redundancy: a secondary NameNode is always running and can take over from the primary NameNode when it fails. The secondary NameNode performs various tasks such as checkpointing (taking snapshots of the NameNode's filesystem image) and performing an edit log to minimize data loss during disaster recovery.

Since the data is replicated thrice in hdfs, does it mean that any calculation done on one node will also be replicated on the other two?

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What happens if the block on Hadoop HDFS is corrupted?

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What should be the HDFS Block size to get maximum performance from Hadoop cluster?

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How to copy file from HDFS to local?

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Can you explain about the indexing process in hdfs?

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Explain how HDFS communicates with Linux native file system?

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Which classes are used by the hive to read and write hdfs files?

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What is NameNode and DataNode in HDFS?

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How to access HDFS?

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What is the procedure to create users in HDFS and how to allocate Quota to them?

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How to use hdfs put command for data transfer from flume to hdfs?

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What is the difference between nas (network attached storage) and hdfs?

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