Block Replication

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 ...