Addy's address APIs are hosted in the cloud across multiple data centres. The APIs are stateless, RESTful services sitting behind a traffic controller to route requests to active APIs. When an address API update is in progress, the incoming traffic will be routed to active APIs so that users do not experience any downtime. Once the address API upgrade is successful, and several address lookup tests were performed, then the updated address API will become active and serve user requests.
This is an effective technique to maximise uptime and to ensure our APIs stay available even during upgrades.
All of our APIs are monitored 24/7 and in the unlikely event that a server fails, all of the traffic will be routed to healthy, online address APIs automatically.