Routing Policy: Geoproximity

The Geoproximity Routing Policy directs user traffic to your infrastructure endpoints based strictly on the absolute physical, mathematical distance between the user and the resource. Unlike Latency routing (which measure real-time network speeds) or Geolocation routing (which maps the rigid geopolitical borders like countries), Geoproximity calculates straight-line coordinates. By applying a mathematical property called a Bias, engineer can artificially expand or shrink a data center's traffic attraction zone.

Key Takeaways​

The Core Mechanics of Bias (1 to 99 vs. -1 to -99)​

Think of Geoproximity as a global tug-of-war map. If you have a server in Singapore (ap-southeast-1) and a server in Sydney (ap-southeast-2) with a bias of 0, Route 53 draws a perfect dividing line right down the middle of Indonesia.

[ Singapore Server ] ──── Bias 0 ──── [ Sydney Server ]
         |                             |
         |                             |
         |                             |
         |                             |
         └────────────┬────────────────┘
                      │
                      │
                      │
                      │
                 Indonesia (Split Zone)

• Positive Bias (1 to 99): Expands the size of that resource's geographic footprint. It acts like a massive gravitational pull, forcing Route 53 to route users to this data center even if they are physically sitting closer to a neighboring region.
• Negative Bias (-1 to -99): Shrinks the resource's geographic footprint. It repels traffic away, deflecting incoming queries to adjacent, surrounding regions instead.

AWS Regions vs. On-Premises Coordinates​

Geoproximity is uniquely designed to seamlessly bridge hybrid-cloud deployments because it calculates positions using raw coordinates:

• AWS Targets: You simply select the explicit AWS Region from a dropdown menu (e.g., ap-southeast-2 for Sydney). Route 53 already knows the exact physical latitude and longitude coordinates of its own global data centers.
• Non-AWS/On-Premises Targets: If you are routing traffic to a private corporate data center sitting in downtown Melbourne, you choose Custom Endpoint and manually input the exact Latitude and Longitude parameters of your building. Route 53 plugs those numbers straight into its distance mapping equations.

Exam Tips​

The exam loves to trap developers by throwing all three location-based routing options into a single scenario.