Updated on 2024-08-14 GMT+08:00

Feature Comparison Details

Protocols

Table 1 Protocols supported by each load balancer type

Protocol

Description

Dedicated Load Balancer

Shared Load Balancer

TCP/UDP (Layer 4)

After receiving TCP or UDP requests from the clients, the load balancer directly routes the requests to backend servers.

Load balancing at Layer 4 features high routing efficiency.

Supported

Supported

HTTP/HTTPS (Layer 7)

After receiving an access request, the listener needs to identify the request and forward data based on the fields in the HTTP/HTTPS packet header.

Load balancing at Layer 7 provides some advanced features such as encrypted transmission and cookie-based sticky sessions.

Supported

Supported

HTTPS support

HTTPS can be used as both the frontend and backend protocol.

Supported

Not supported

QUIC

If you use UDP and QUIC as the frontend protocol, you can select QUIC as the backend protocol, and select the connection ID algorithm to route requests with the same connection ID to the same backend server.

QUIC has the advantages of low latency, high reliability, and no head-of-line blocking (HOL blocking), and is very suitable for the mobile Internet. No new connections need to be established when you switch between a Wi-Fi network and a mobile network.

Supported

Not supported

HTTP/2

Hypertext Transfer Protocol 2.0 (HTTP/2) is a new version of the HTTP protocol. It is compatible with HTTP/1.X and provides improved performance and security.

Only HTTPS listeners support this feature.

Supported

Supported

WebSocket

WebSocket is a new HTML5 protocol that provides full-duplex communication between the browser and the server. WebSocket saves server resources and bandwidth, and enables real-time communication.

Supported

Supported

Network Configurations

Table 2 Network configuration comparison

Feature

Description

Dedicated Load Balancer

Shared Load Balancer

Public IPv4 network

The load balancer routes requests from the clients to backend servers over the Internet.

Supported

Supported

Private IPv4 network

The load balancer routes requests from the clients to backend servers in a VPC.

Supported

Supported

IPv6 network

Load balancers can route requests from IPv6 clients.

Supported

Not supported

Changing a private IPv4 address

You can change the private IPv4 address into another one in the current subnet or other subnets.

Supported

Not supported

Binding or unbinding an EIP

You can bind an EIP to a load balancer or unbind the EIP from a load balancer based on service requirements.

Supported

Supported

Modifying the bandwidth

You can change the bandwidth of public network load balancers as required.

Supported

Supported

Key Features of Listeners

Table 3 Comparison of key features

Feature

Description

Dedicated Load Balancer

Shared Load Balancer

Access Control

You can add IP addresses to a whitelist or blacklist to control access to a listener.

  • A whitelist allows specified IP addresses to access the listener.
  • A blacklist denies access from specified IP addresses.

Supported

Supported

Mutual Authentication

This feature allows the clients and the load balancer to authenticate each other. Only authenticated clients will be allowed to access the load balancer.

Mutual authentication is supported only by HTTPS listeners.

Supported

Supported

SNI

Server Name Indication (SNI) is an extension to TLS and is used when a server uses multiple domain names and certificates. After SNI is enabled, certificates corresponding to the domain names are required.

SNI can be enabled only for HTTPS listeners.

Supported

Supported

Transfer Client IP Address

This feature allows backend servers to obtain the real IP addresses of the clients.

This feature is enabled for dedicated load balancers by default and cannot be disabled.

Supported

Supported

Advanced features of HTTP/HTTPS listeners

Default Security Policy

Allows you to select appropriate security policies to improve service security when you add HTTPS listeners. A security policy is a combination of TLS protocols and cipher suites.

Supported

Supported

Custom Security Policy

Allows you to select a TLS protocol and cipher suite to custom a security policy when you add HTTPS listeners.

Supported

Not supported

Transfer Load Balancer EIP

Allows you to store the EIP bound to the load balancer in the X-Forwarded-ELB-IP header and pass it to backend servers.

Supported

Supported

Forwarding Capabilities

You can add forwarding policies to HTTP or HTTPS listeners to forward requests to different backend server groups. Advanced forwarding policies are available only for dedicated load balancers.

You can set forwarding rules and actions for a forwarding policy. For details, see Table 4 and Table 5.

Table 4 Forwarding rules supported by each load balancer type

Forwarding Rule

Description

Dedicated Load Balancer

Shared Load Balancer

Domain name

Route requests based on the domain name. The domain name in the request must exactly match that in the forwarding policy.

Supported

Supported

URL

Route requests based on the URLs.

There are three URL matching rules: exact match, prefix match, and regular expression match.

Supported

Supported

HTTP request method

Route requests based on the HTTP method.

The options include GET, POST, PUT, DELETE, PATCH, HEAD, and OPTIONS.

Supported

Not supported

HTTP header

Route requests based on the HTTP header.

An HTTP header consists of a key and one or more values. You need to configure the key and values separately.

Supported

Not supported

Query string

Route requests based on the query string.

Supported

Not supported

CIDR block

Route requests based on source IP addresses from where the requests originate.

Supported

Not supported

Table 5 Actions supported by each load balancer type

Action

Description

Dedicated Load Balancer

Shared Load Balancer

Forward to a backend server group

Forward requests to the specified backend server group.

Supported

Supported

Redirect to another listener

Redirect requests to an HTTPS listener, which then routes the requests to its associated backend server group.

Supported

Not supported

Redirect to another URL

Redirect requests to the configured URL.

When clients access website A, the load balancer returns 302 or any other 3xx status code and automatically redirects the clients to website B. You can custom the redirection URL that will be returned to the clients.

Supported

Not supported

Return a specific response body

Return a fixed response to the clients.

You can custom the status code and response body that load balancers directly return to the clients without the need to route the requests to backend servers.

Supported

Not supported

Key Features of Backend Server Groups

Table 6 Key features supported by each load balancer type

Key Feature

Description

Dedicated Load Balancer

Shared Load Balancer

Health check

ELB periodically sends requests to backend servers to check their running statuses. This process is called health check. You can perform health checks to determine whether a backend server is available.

Supported

Supported

Sticky session

Requests from the same client will be routed to the same backend server during the session.

Supported

Supported

Slow start

The load balancer linearly increases the proportion of requests to the new backend servers added to the backend server group.

Slow start gives applications time to warm up and respond to requests with optimal performance.

Supported

Not supported

Active/Standby forwarding

The load balancer routes the traffic to the active server if it works normally and to the standby server if the active server becomes unhealthy.

You must add two backend servers to the backend server group, one acting as the active server and the other as the standby server.

Supported

Not supported

Load Balancing Algorithms

Table 7 Load balancing algorithm comparison

Load Balancing Algorithm

Description

Dedicated Load Balancer

Shared Load Balancer

Weighted round robin

Route requests to backend servers using the round robin algorithm. Backend servers with higher weights receive proportionately more requests, whereas equal-weighted servers receive the same number of requests.

Supported

Supported

Weighted least connections

Route requests to backend servers with the smallest ratio (current connections divided by weight).

Supported

Supported

Source IP hash

Route requests from the same client to the same backend server within a period of time.

Supported

Supported

Connection ID

Calculate the source IP address of each request using the consistent hashing algorithm to obtain a unique hash key and route the requests to the particular server based on the generated key.

Supported

Not supported

Backend Server Type

Table 8 Supported backend server types

Backend Server Type

Description

Dedicated Load Balancer

Shared Load Balancer

IP as backend server

You can add servers in a peer VPC, in a VPC that is in another region and connected through a cloud connection, or in an on-premises data center at the other end of a Direct Connect or VPN connection, by using the server IP addresses.

Supported

Not supported

Supplementary network interface

You can attach supplementary network interfaces to backend servers.

Supported

Not supported

ECS

You can use load balancers to distribute incoming traffic across ECSs.

Supported

Supported

BMS

You can use load balancers to distribute incoming traffic across BMSs.

Supported

Supported

CCE Turbo cluster

You can use load balancers to distribute incoming traffic across CCE Turbo clusters. For details, see the Cloud Container Engine User Guide.

Supported

Supported