Application Scenarios

Heavy-Traffic Applications

For an application with heavy traffic, such as a large portal or mobile app store, ELB evenly distributes incoming traffic across backend servers, balancing the load while ensuring steady performance.

Sticky sessions ensure that requests from one client are always forwarded to the same backend server for fast processing.

Figure 1 Session stickiness

Applications with Predictable Peaks and Troughs in Traffic

For an application that has predictable peaks and troughs in traffic volumes, ELB works with Auto Scaling to automatically add servers during promotions when there are sudden traffic spikes, and then remove them when traffic returns to normal. This helps you improve resource availability and reduce IT costs.

Figure 2 Flexible scalability

Zero SPOFs

ELB routinely performs health checks on backend servers to monitor their health. If any backend server is detected unhealthy, ELB will not route requests to this server until it recovers.

This makes ELB a good choice for running services that require high reliability, such as websites.

Figure 3 Eliminating SPOFs

Cross-AZ Load Balancing

ELB can distribute traffic across AZs. When an AZ becomes faulty, ELB distributes traffic across backend servers in other AZs.

ELB is ideal for banking, policing, and large application systems that require high availability.

Figure 4 Traffic distribution to servers in one or more AZs