How Does Azure Traffic Manager Work?

Azure Traffic Manager’s design includes several features that optimize global application performance and availability.

• DNS-Level Traffic Management

  Azure Traffic Manager operates at the DNS level, directing traffic based on the DNS name resolution of each user request. This process ensures traffic is routed efficiently without handling the data flow between clients and services. The traffic is passed directly to the service endpoint after DNS resolution, which minimizes overhead and improves performance. Since this system works at the DNS level, it does not impact the actual transfer of data, which further optimizes performance and scalability.

• Endpoint Health Monitoring & Automatic Failover

  Another powerful feature of Traffic Manager is its continuous health monitoring of endpoints. Azure Traffic Manager deploys multiple probes to monitor the health of each service endpoint.
  The system continuously checks the status of these probes to determine whether an endpoint is healthy. If the threshold for probe statuses falls below 0.5 (meaning fewer than 50% of the probes are functioning), Traffic Manager triggers an alert for endpoint failure and redirects traffic to a healthy endpoint.

• Support for Azure & External Endpoints

  Traffic Manager supports a hybrid approach, allowing you to manage traffic between Azure-hosted services and external endpoints outside of Azure. This feature is especially useful for businesses operating in hybrid cloud or multi-cloud environments. You can integrate non-Azure services such as on-premises servers, websites, or services hosted on other cloud platforms.

Let us break down the process in a step-by-step manner to understand how it functions:

1. User Request Initiated : A user initiates a request by accessing your website or application. Their device makes a DNS query to resolve the domain name (e.g., www.yourwebsite.com) into an IP address.
2. Recursive DNS Service: The user’s DNS request is forwarded to a recursive DNS server, which resolves the domain name. In this case, it finds that the name is mapped to an Azure Traffic Manager profile.
3. Traffic Manager Decision: The Traffic Manager name servers receive the DNS request and decide which service endpoint should be used based on:
   • The health status of endpoints (unhealthy endpoints are excluded).
   • The chosen routing method (priority, geographic, performance, etc.).
4. Routing the User: Once the appropriate endpoint is selected, the Traffic Manager sends a DNS response back to the user’s device, which then connects directly to the selected endpoint to access the service.

Azure Traffic Manager offers multiple traffic routing methods, each designed for different application needs.

• Geographic Routing

  This method routes traffic based on the geographic location of the user. It is commonly used to comply with regional regulations or deliver content from a local service to reduce latency. For example, European users would be directed to a European data center, while users in North America would be directed to a North American endpoint​.

• Performance Routing

  Performance routing improves the responsiveness of applications by routing traffic to the endpoint with the lowest network latency relative to the user’s location. It does not always select the closest endpoint geographically but uses latency measurements to determine the fastest connection for the user.

• Weighted Routing

  This method allows you to distribute traffic based on assigned weights. For example, if you want 70% of your traffic to be directed to Endpoint A and 30% to Endpoint B, weighted routing makes this possible. This is particularly useful for load balancing or gradual migration between endpoints​.

• Priority Routing

  Priority routing ensures that all traffic is directed to the primary endpoint, which has the highest priority. If the primary endpoint becomes unavailable, Traffic Manager automatically redirects traffic to the next available endpoint in the priority list. This method is ideal for failover scenarios where certain endpoints serve as backups.

• Subnet & Multi-Value Routing

  Subnet routing directs traffic based on specific IP address ranges, ensuring that particular users or groups of users are routed to designated endpoints.Multi-Value routing is used when you have multiple endpoints, such as for services with IPv4 and IPv6 addresses. It returns all healthy endpoints to the DNS query, allowing the client to choose from several options​.

Below are several common use cases that illustrate the flexibility and power of Traffic Manager.

• Global High Availability

  In today’s interconnected world, applications are often deployed across multiple regions to ensure that they are available to users regardless of their geographic location. Azure Traffic Manager enhances global high availability by distributing user traffic to the healthiest and closest endpoints. This ensures that applications remain operational, even if one or more regions experience service outages.
  For example, a company with users in Europe, North America, and Asia can deploy their application in data centers located in each of these regions. Azure Traffic Manager will automatically route users to the most responsive data center based on their location and the health of each endpoint. If the North American data center experiences downtime, Traffic Manager will direct users to either the European or Asian endpoints, ensuring continued service availability.

• Hybrid Cloud and On-Premises Scenarios

  Many organizations operate in a hybrid cloud environment, where they maintain a mix of on-premises infrastructure and cloud-based services. Azure Traffic Manager supports hybrid deployments by directing traffic between both Azure-based and external endpoints.
  A common use case for hybrid cloud scenarios is “bursting to the cloud” during periods of high demand. For example, an e-commerce company might run its core infrastructure on-premises but use Azure to handle traffic spikes during seasonal sales. Traffic Manager can direct traffic to the cloud only when the on-premises infrastructure reaches capacity, preventing downtime and performance degradation​.

• Disaster Recovery

  Azure Traffic Manager plays a key role in disaster recovery plans, ensuring that services remain accessible even in the event of catastrophic failures. For instance, a financial institution with critical services deployed in the U.S. may use Traffic Manager to maintain a backup deployment in Europe. Suppose the primary U.S. deployment experiences an outage due to a natural disaster or network failure. In that case, the Traffic Manager will redirect user traffic to the European backup, maintaining service continuity without any manual intervention.

• Scalability for Complex Deployments

  Large organizations often deploy complex infrastructure that spans multiple regions and may include various application tiers, microservices, and multi-cloud strategies. Azure Traffic Manager allows you to use nested profiles, combining different traffic routing methods to scale to the needs of larger, more complex deployments.
  For instance, a global SaaS provider might use weighted routing to balance traffic across several data centers and performance routing to ensure optimal service for users in different regions. By nesting profiles, they can apply different routing methods to different layers of their infrastructure, providing fine-tuned control over traffic distribution.

Azure Traffic Manager is a vital tool for any business looking to optimize their global applications. It offers flexibility through its various routing methods, resilience with automatic failover, and improved user experiences by minimizing latency. 

At OTAVA, we specialize in helping businesses implement and optimize Azure Traffic Manager to meet their specific needs. For businesses requiring highly customized configurations—like nested profiles and multi-layer routing setups—our specialists work closely with you to design and implement advanced traffic management solutions. Contact us today to find out how we can help you take full advantage of Azure Traffic Manager for your business.