High availability and Fault tolerance

High availability and Fault tolerance

High availability:

  • Minimal service interruption
  • Designed with no single point of failure
  • Uptime measured in percentage, like 99.9999%
  • Lower cost compared to Fault tolerance
  • Examples services create High Availability : Elastic load balancers, EC2 auto scaler, Amazon Route 53

Fault tolerance:

  • No service interruption
  • Specialized hardware with instant failover functionality
  • No downtime
  • Higher cost compared to High Availability
  • Examples of Fault Tolerance :  Disk mirroring, Synchronous Database replication, redundant power.

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