Introduction
Load balancing in simplest terms refers to dynamically distributing application incoming network traffic across a group of backend nodes. It helps to maintain high availability, scalability, fault-tolerance of your application and gives a smooth experience to the application users because applications are serving hundreds of thousands, or millions, of concurrent requests from users or clients and return the correct response as per request. To cost-effectively scale to meet these high volumes, modern computing best practice generally requires adding more servers.
A load balancer acts as a single point of contact for the application. It helps to manage your application servers and to route users/client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance. If a single server goes down, the load balancer redirects traffic to the remaining online servers. When a new server is added to the server group, the load balancer automatically starts to send requests to it.
Load distribution decision is based on the configured process and the traffic that is coming to the application. It checks connection requests from clients, using the protocol and port that you configure for front-end (client to load balancer) connections. It forwards requests to one or more registered backend nodes using the protocol and port number that you set for back-end (load balancer to backend nodes) connections.
The following are the essential characteristics of Load balancer:
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You have the flexibility to add and remove backend nodes from your load balancer to handle traffic load based on requirement changes without interrupting the flow of user requests to your application.
- Registering Nodes adds them to the load balancer, which starts routing requests to them.
- Deregistering Nodes removes them, and they stop receiving traffic, though they remain running. You can re-register them as needed.
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When you create a load balancer, you must choose between an internal load balancer (private IP) and an external load balancer (public IP).
- External load balancers route Internet traffic to backend nodes.
- Internal load balancers route traffic over private subnets.
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E2E Load balancers support various load balancing algorithms, each with specific benefits depending on your needs.
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Monitoring provides real-time health insights and metrics of load balancer operations on the MyAccount portal. Learn more about Monitoring
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Alerts can be configured to notify you about critical load balancer health changes via email. Learn more about Alerts
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Reserved IP can be attached as either:
- An add-on IP associated with the load balancer's primary network interface.
- A primary public IP for the load balancer interface. Learn more about Reserved IP
