Traffic Manager

Microsoft Azure Traffic Manager provides a feature to distribute user traffic to different endpoints. These endpoints can be Azure App Service (Azure Web Apps), cloud services, Azure Virtual Machines, and external endpoints. It is a DNS-based traffic routing. Azure Traffic Manager supports three traffic routing methods to decide how traffic can be routed to different endpoints. In simple terms, it is a way to decide which endpoint should serve the DNS request.

There are two different deployment models in Microsoft Azure—the classic deployment and Resource Manager deployment models. Microsoft Azure Traffic Manager uses different terminology for traffic routing methods (known as the load-balancing method in the classic deployment model):

• Priority method (Failover method): Select the Priority or Failover method for traffic routing when you need resources in a specific region to serve all the traffic and only use other endpoints if the main endpoint is unavailable.

Often this method is cost-optimized and the usage of the application is very well known and specific to a region.

• Weighted method (Round-robin method): Select the Weighted or Round-robin method for traffic routing when you need resources to serve in a different region or across a set of different endpoints.

Let's say we know that our application hosted in Azure Web Apps is going to be equal or in a specific ratio, then the Weighted method can be more appropriate.

• Performance method: Select Performance for the traffic routing method when we want to provide equal performance to the user of the resources hosted in Azure.

So, in simple terms, users will be redirected to the nearest endpoint to serve the response.
Some benefits of Microsoft Azure Traffic Manager are as follows:

• Easy to use and configure
• Easy learning curve
• Configuration is available from Azure Portal as well as Azure PowerShell 
• DNS level traffic routing
• Helps in high availability of the business critical application
• Provides automatic failover
• Supports multiple endpoints: Microsoft Azure and external endpoints
• Helps to support the scenario of planned maintenance
• We can combine hybrid applications as it supports multiple endpoints