Redundancy

• Redundancy: duplication of critical data or services with the intention of increased reliability of the system.
• Server failover
  • Remove single points of failure and provide backups (e.g. server failover).
• Shared-nothing architecture
  • Each node can operate independently of one another.
  • No central service managing state or orchestrating activities.
  • New servers can be added without special conditions or knowledge.
  • No single point of failure.