Azure load balancing solutions ​

Azure provides a suite of fully managed load-balancing solutions for your scenarios.

Azure load balancing services can be categorized in two ways:

• Global versus regional.
• HTTP(S) versus non-HTTP(S).

The table below summarizes these categorizations for each Azure load balancing service.

Azure Load Balancer ​

See detailed information about [Azure Load Balancer here]insert link to Azure Load Balancer article

High-performance, ultra-low-latency Layer 4 load-balancing service (inbound and outbound) for all UDP and TCP protocols. It is built to handle millions of requests per second while ensuring your solution is highly available. Azure Load Balancer is zone-redundant, ensuring high availability across Availability Zones.

Summary:

• Ultra-low-latency
• Regional or Global
• non-HTTP(S)
• Layer 4
• Zone redundant
  • HA across Availability Zones

Traffic manager ​

See detailed information about [Traffic manager here]insert link to traffic manager article

If you're looking to do DNS based global routing and do not have requirements for Transport Layer Security (TLS) protocol termination ("SSL offload"), per-HTTP/HTTPS request or application-layer processing, review Traffic Manager.

Summary:

• Global
• non-HTTP(S)
• DNS-based traffic load balancer
• load-balances only at the domain level
• Can't fail over as quickly as Front Door

Azure Application Gateway ​

See detailed information about [Azure Application Gateway]insert link to Azure Application Gateway article

Summary:

• Regional
• HTTP(S)
• Application delivery controller (ADC) as a service
• Layer 7 load-balancing
• Offload CPU-intensive SSL terminations to the gateway.

Azure Front Door ​

See detailed information about [Azure Front Door here]insert link to Azure Front Door article

Summary:

• Global
• HTTP(S)
• Application delivery network (ADN)
• Global load balancing
• Site acceleration service
• Layer 7 capabilities
  • SSL offload
  • Path-based routing
  • Fast failover
  • Caching

Global load-balancing services ​

Distribute traffic across:

• Regional backends
• Clouds
• Hybrid on-premises services

These services route end-user traffic to the closest available backend. They also react to changes in service reliability or performance, in order to maximize availability and performance. You can think of them as systems that load balance between application stamps, endpoints, or scale-units hosted across different regions/geographies.

Regional load-balancing services ​

Distribute traffic within:

• Virtual networks across virtual machines (VMs)
• Zonal and zone-redundant service endpoints within a region.

You can think of them as systems that load balance between VMs, containers, or clusters within a region in a virtual network.

HTTP(S) versus non-HTTP(S) ​

HTTP(S) load-balancing services

• Layer 7 load balancers that only accept HTTP(S) traffic
• Intended for web applications or other HTTP(S) endpoints
• Include features such as:
  • SSL offload
  • Web application firewall
  • Path-based load balancing
  • Session affinity

non-HTTP(S) load-balancing services

• Can handle non-HTTP(S) traffic
• Recommended for non-web workloads.

Choosing a load balancing option for Azure ​

When choosing an appropriate load balancing option, there are some key factors to consider:

Type of traffic

• is it for a web application? Is it a public-facing or private application?

Scope

• Do you need to load balance virtual machines and containers within a virtual network, or load balance across regions, or both? (see 'Global versus regional' above)

Availability

• What is the Service Level Agreement (SLA) for the service?

Cost

• In addition to the cost of the actual service itself, consider the operational cost to manage and maintain a solution built on that service.

Features and limitations

• What features and benefits does each service provide, and what are its limitations?

The flowchart below will help you to select the most appropriate load-balancing solution for your application, by guiding you through a set of key decision criteria in order to reach a recommendation.

As every application will have its own unique requirements, you should only use this flowchart and the suggested recommendation as a starting point, and then perform a more detailed evaluation yourself in order to select the best option for your environment.

If your application consists of multiple workloads, evaluate each workload separately. A complete solution may incorporate two or more load-balancing solutions.

Selecting a load balancing solution by using the Azure portal ​

You can use the Azure Load Balancing page in the Azure portal to help you guide to the right load-balancing solution for your business need. Azure Load Balancing includes the decision-making queries described in the workflow diagram above.

Sign into the Azure portal at https://portal.azure.com.

1. In the search box at the top of the page, type load balancing. When Load balancing - help me choose (Preview) appears in the search results, click it.

2. Answer the Yes or No questions on this page to get a recommended solution. Note, that the final recommended solution may be a combination of multiple load balancing services.

3. Depending on what answers you give, the list of potential load balancing services will change.

4. Optionally, you can also click the Service comparison or Tutorial tabs for more information and training on the different load balancing services.