Block Replication
Explore the concept of block replication in HDFS to understand how Hadoop maintains fault tolerance and high availability. Learn about the replication factor, node selection strategies, and how distributed copies of data blocks ensure continuous service despite hardware failures or data corruption.
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Block Replication
Before discussing what makes HDFS fault-tolerant and highly available, let’s first understand the term fault tolerance. Wikipedia defines fault tolerance as the property that enables a system to continue operating properly in the event of the failure of some of its components. Said another way, fault tolerant computing is a form of full hardware redundancy. Two (or more) systems operate in tandem, mirroring identical applications and executing instructions in lock step. When a hardware failure occurs in the primary system, the secondary system running an identical ...