Fail Over

Tags

sys-design

Is a way to support highly available systems by having multiple servers act as fallbacks for the main one.

This can come in 2 varieties:

• Active Passive - Heartbeats between active and passive server, passive takes over (including actives Ip) once active stops responding.
• Active Active - Both servers manage traffic, spreading the load between them.

Downsides:

• More hardware, more complexity.
• Chance for data loss if active crashes while working on request and passive takes over.