What Is Elastic Load Balance?
Elastic Load Balance (ELB) automatically distributes incoming traffic across multiple backend servers based on a set of rules that you configure. ELB expands the service capabilities of applications and improves their availability by eliminating single points of failure (SPOFs).
Load balancers receive requests from clients and route the requests to backend servers in one or more availability zones (AZs).
After creating a load balancer, you need to add at least one listener to it. Listeners use the protocol and port that you have configured to check requests from clients and forward the requests to backend servers in a backend server group using the selected load balancing algorithm. For HTTP and HTTPs listeners, you can configure forwarding policies to route requests based on domain names or URLs.
Backend server groups each uses the protocol and port that you have specified to forward requests to one or more backend servers.
ELB provides the health check function to check the running status of each backend server. When the health check result of a backend server is Abnormal, ELB automatically stops distributing new requests to this server until it recovers.
Access to ELB
You can use either of the following methods to access ELB:
- Management console
A graphical user interface has been provided for you. To access the service, log in to the management console and choose All Services > Network > Elastic Load Balance, or choose Service List > Network > Elastic Load Balance.
You can make calls to APIs to access ELB. For details, see the Elastic Load Balance API Reference.