Geoproximity Routing Policies | Overview.

Geoproximity Routing Policies - Overview.

Geoproximity routing in Amazon Route 53 allows twtech to route traffic based on the geographic location of users and the location of the resources, with the ability to apply biases to shift traffic between them.

 NB: 

• Geoproximity routing is available only via Route 53 Traffic Flow, not as a standalone routing policy like geolocation.

 Use Case

twtech may want to route traffic mostly to the closest AWS region (e.g., US-East or EU-West), but also want to:

• Shift traffic away from an overloaded region (e.g., 20% from US to EU).
• Push more users to a newer region to balance traffic gradually.

 How It Works

• Each routing rule is based on:
• User's location (inferred from DNS resolver IP)
• Resource location (AWS region or custom lat/lon if non-AWS)
• twtech defines bias values to expand or shrink the area from which traffic is routed to each location.

 Bias Explained

Bias controls how much more or less traffic a region gets:

• Positive bias (+ value) = Expand the region’s influence.
• Negative bias (− value) = Shrink the region’s influence.

Bias ranges from -99 to +99

 Example Scenario

Region	Bias	Outcome
US-East (N. Virginia)	0	Normal coverage based on proximity
EU-West (Ireland)	+50	Gets more traffic than it would normally
Asia (Singapore)	-50	Gets less traffic, only very nearby users

 Custom Location (Non-AWS)

• twech can specify a custom location (lat/lon) for a resource if it’s not hosted in AWS, and Route 53 will use that in distance calculations.

 Optional: Health Checks

• Geoproximity Routing Policies Combine with health checks, ensure that only healthy endpoints receive traffic.

 Geoproximity vs Geolocation vs Latency

Feature	Based On	Bias Support	Health Check	Use Case
Geoproximity	User & resource location	✅ Yes	✅ Yes	Route traffic mostly based on proximity, shift with bias
Geolocation	User location only	❌ No	✅ Yes	Show region-specific content (e.g., languages)
Latency-based	Network latency	❌ No	✅ Yes	Route to the lowest-latency endpoint

 Route 53 Traffic Flow Console

• Geoproximity routing is configured using a Traffic Flow Policy, which gives twtech:
• A visual flow chart to configure routing logic.
• The ability to export policies as JSON or automate via API/SDK.

 Limitations

• Not available directly in the "Routing Policy" dropdown — must use Traffic Flow.
• Bias tweaking can be a bit trial-and-error.
• Requires Route 53 hosted zone and public DNS.