Azure Traffic Manager is a DNS-based load balancer to manage user traffic distribution of service endpoints in different data centers. This tool can service any of the Azure global regions and secure an optimal level of availability and responsiveness for your services.
Traffic Manager uses DNS to direct the client requests to the appropriate service endpoint based on a traffic-routing method. Traffic manager also provides health monitoring for every endpoint. The endpoint can be any Internet-facing service hosted inside or outside of Azure
Traffic Manager Features
Increase application availability
It provides high availability for your critical applications by monitoring your endpoints and delivering automatic failover when an endpoint goes down.
Improve application performance
Azure allows you to run cloud services or websites in data centres located all over the world. It enhances application responsiveness by directing traffic to the endpoint with the lowest network latency for the client.
Perform service maintenance without downtime
You can perform planned maintenance operations on your applications without downtime. It can direct traffic to alternative endpoints while the maintenance is ongoing.
Combine hybrid applications
Microsoft Azure Traffic Manager supports external, non-Azure endpoints enabling it to be used with hybrid cloud and on-premises deployments, including the “burst-to-cloud”, “migrate-to-cloud,” and “failover-to-cloud” scenarios.
Distribute traffic for complex deployments
Using nested Azure Traffic Manager profiles, multiple traffic-routing methods are often combined to make sophisticated and versatile rules to scale to the requirements of larger, more complex deployments.
Traffic Manager Routing Method
Azure Traffic Manager supports six traffic-routing methods to determine how to route network traffic to the various service endpoints.
The following traffic routing methods are available in Traffic Manager
Priority
Select Priority routing when you want to have a primary service endpoint for all traffic. You can provide multiple backup endpoints in case the primary or one of the backup endpoints is unavailable.
Weighted
Select Weighted routing when you want to distribute traffic across a set of endpoints based on their weight. Set the weight the same to distribute evenly across all endpoints.
Performance
Select Performance routing when you have endpoints in different geographic locations and you want end users to use the "closest" endpoint for the lowest network latency.
Geographic
Select Geographic routing to direct users to specific endpoints (Azure, External, or Nested) based on where their DNS queries originate from geographically. With this routing method, it enables you to be in compliance with scenarios such as data sovereignty mandates, localization of content & user experience and measuring traffic from different regions.
Multivalue
Select MultiValue for Traffic Manager profiles that can only have IPv4/IPv6 addresses as endpoints. When a query is received for this profile, all healthy endpoints are returned.
Subnet
Select Subnet traffic-routing method to map sets of end-user IP address ranges to a specific endpoint. When a request is received, the endpoint returned will be the one mapped for that request’s source IP address.
Traffic Manager SKUs
Traffic Manager billing is based on the number of DNS queries received, with a discount for services receiving more than 1 billion monthly queries. Microsoft also charge for each monitored endpoint (the rate depends on whether it’s an Azure or external service).