Active-Passive vs Active-Active Redundancy

by Iwan Price-Evans on High Availability • September 2, 2019

If an active instance goes offline, passive instances begin to operate as active nodes servicing requests.

Mechanisms such as Virtual Router Redundancy Protocol (VRRP) along with floating IPs can be used to facilitate seamless network endpoint failover among the active-passive redundant instances.

A client can connect to any one instance and have requests served in the same way.

If any of the identical instances go offline, any of the other instances can seamlessly serve requests while client sessions persist.