Help Center/ Elastic Load Balance/ Drawer/ Buying a Load Balancer/ Differences Between Dedicated and Shared Load Balancers
Updated on 2025-07-25 GMT+08:00

Differences Between Dedicated and Shared Load Balancers

Introduction

Elastic Load Balance (ELB) automatically distributes incoming traffic across multiple backend servers based on the configured routing rules. ELB expands the service capabilities of your applications and improves their availability by eliminating single points of failure (SPOFs).

Load Balancer Types

ELB provides shared load balancers and dedicated load balancers.

  • Dedicated load balancers: A dedicated load balancer gets dedicated resources. Its performance is never affected by the loads on other load balancers. In addition, there are elastic and fixed specifications available for you to choose from.
  • Shared load balancers: They are deployed in clusters and share resources with other instances. If the number of connections exceeds that defined by guaranteed performance, their performance may be affected by the loads on other load balancers.

Available specifications are displayed on the console and may vary by region.

Feature Comparison

Item

Dedicated Load Balancer

Shared Load Balancer

Capabilities

They have powerful capabilities to process Layer 4 and Layer 7 requests and support advanced forwarding policies and the following protocols:

  • Frontend protocols: TCP, UDP, HTTP, HTTPS, and TLS
  • Backend protocols: TCP, UDP, HTTP, HTTPS, QUIC, and TLS

They have basic capabilities to process Layer 4 and Layer 7 requests and support the following protocols:

  • Frontend protocols: TCP, UDP, HTTP, and HTTPS
  • Backend protocols: TCP, UDP, and HTTP

Application scenarios

High-traffic and high-concurrency services, such as large websites, cloud native applications, IoV, e-commerce, social and content platforms, gaming and entertainment, and multi-AZ DR applications

Services with low traffic, such as small websites and common HA applications

Deployment mode

The performance of a dedicated load balancer is never affected by the loads on other load balancers. There are elastic and fixed specifications available for you to choose from.

A dedicated load balancer in an AZ can establish up to 20 million concurrent connections. If you deploy a dedicated load balancer in multiple AZs, the number of concurrent connections will multiply.

Shared load balancers are deployed in clusters and share resources with other instances. They support guaranteed performance.

If you enable the guaranteed performance option, a shared load balancer can handle up to 50,000 concurrent connections, 5,000 new connections per second, and 5,000 queries per second. If the number of connections exceeds that defined by guaranteed performance, their performance is not guaranteed.

Forwarding capabilities

They forward requests based on the following:

  • Forwarding rules: domain name, path, HTTP request method, HTTP header, query string, and CIDR block
  • Actions: forward to a backend server group, redirect to another listener, redirect to another URL, rewrite, and return a specific response body

They forward requests based on the following:

  • Forwarding rules: domain name and path
  • Actions: forward to a backend server group and redirect to another listener

Backend type

  • ECS
  • IP as backend server
  • Supplementary network interface
  • BMS
  • CCE Turbo cluster
  • ECS
  • BMS
  • CCE Turbo cluster

For more information, see Feature Comparisons Details.

FAQ