This topic describes the release notes for Server Load Balancer (SLB) and provides links to the relevant references.

March 2022

Feature Description References
Functions of Function Compute can be specified as backend servers of ALB. Functions of Function Compute can be specified as backend servers of ALB. ALB can be configured to forward requests from ALB to Function Compute. Specify a function from Function Compute as a backend server of ALB

January 2022

Feature Description References
Servers across virtual private clouds (VPCs) in different regions can be added to Application Load Balancer (ALB). Backend servers can be specified for the server groups of Application Load Balancer (ALB) by IP address. Requests received by ALB can be routed to servers in other regions by using Cloud Enterprise Network (CEN) transit routers. Add ECS instances in a VPC to an ALB instance in a different region
On-premises servers can be added to Application Load Balancer (ALB). Backend servers can be specified for the server groups of Application Load Balancer (ALB) by IP address. Requests received by ALB can be routed to on-premises servers by using CEN transit routers and other services. Specify an on-premises server as a backend server of ALB

November 2021

Feature Description References
A higher level of service uptime is guaranteed for Application Load Balancer (ALB) instances that support multi-zone deployment. The service uptime guaranteed for Application Load Balancer (ALB) instances that support multi-zone deployment is improved from 99.95% to 99.995%. SLB Service Level Agreement

September 2021

Feature Description References
ALB resource plans (subscription) are supported. Subscription resource plans are provided by ALB. After an ALB resource plan takes effect, it can automatically offset the Load Balancer Capacity Unit (LCU) fees and instance fees for ALB. Compared with the pay-as-you-go billing method, ALB resource plans are more cost-effective. You can specify the time when you want a resource plan to take effect as needed. ALB resource plans are suitable for enterprises on a fixed budget.

August 2021

Feature Description References
EIP bandwidth plans can be associated with ALB. An existing EIP and an EIP bandwidth plan can be associated with an ALB instance when you create the ALB instance. After the ALB instance is associated with an EIP bandwidth plan, the ALB instance shares the bandwidth of the EIP bandwidth plan. This reduces bandwidth costs. ALB quick start

July 2021

Feature Description References
Proxy Protocol can be used by CLB to retrieve client IP addresses. Proxy Protocol can be used by Layer 4 listeners of CLB to pass client IP addresses to backend servers. After Proxy Protocol is enabled, CLB adds a TCP header to the request without modifying the existing headers. The TCP header carries information such as the source IP address, destination IP address, source port, and destination port. Enable Proxy Protocol for a Layer 4 listener to retrieve client IP addresses

March 2021

Feature Description References
Mutual authentication is supported by ALB. Mutual authentication is supported by HTTPS listeners of ALB. Add an HTTPS listener

Manage certificates

Outbound forwarding rules are supported by ALB. Inbound and outbound forwarding rules are both supported by ALB. Manage forwarding rules for a listener

January 2021

Feature Description References
The monitoring feature of CLB is optimized. The monitoring feature of CLB is optimized. By default, the health check data of forwarding rules is no longer displayed. Set alert rules in the CloudMonitor console

October 2020

Feature Description References
ALB is released for public preview. A free trial of ALB, a load balancing service intended for Layer 7, is available. What is Application Load Balancer (ALB)?

July 2019

Feature Listener References
Health checks are supported.

TCP

UDP

HTTP

HTTPS

Execute a health check script
The Overview page of SLB is available.

TCP

UDP

HTTP

HTTPS

-

June 2019

Feature Listener References
UDP and TCP listeners that belong to the same SLB instance and listen on the same port are supported in more regions.

TCP

UDP

Add a TCP listener

Add a UDP listener

Backend servers can be added by specifying secondary IP addresses of elastic network interfaces (ENIs) that are attached to ECS instances.

UDP

TCP

HTTP

HTTPS

Add backend servers by specifying their ENIs

May 2019

Feature Listener References
A port can be listened by both a UDP and a TCP listener within the same SLB instance.

UDP

TCP

Add a TCP listener

Add a UDP listener

Elliptic curve keys are supported. HTTPS Certificate requirements
TLS 1.3 is supported. HTTPS TLS security policies
The GET method for health checks is supported by Layer 7 listeners.

HTTPS

HTTP

Add an HTTP listener

Add an HTTPS listener

April 2019

Feature Listener References
Available resources in zones can be queried by calling the API.

HTTPS

HTTP

UDP

TCP

DescribeAvailableResource
IPv6 is supported.

HTTPS

HTTP

UDP

TCP

Overview of IPv6 CLB instances

January 2019

Feature Listener References
Idle instance management is supported.

HTTPS

HTTP

UDP

TCP

Manage idle CLB instances

December 2018

November 2018

Feature Listener References
HTTP requests can be redirected to HTTPS.

HTTP

Redirect HTTP requests to HTTPS

October 2018

Feature Listener References
Backend servers can be added by specifying ENIs that are attached to ECS instances in the console.

HTTPS

HTTP

UDP

TCP

Add backend servers by specifying their ENIs

September 2018

Feature Listener References
Certificates provided by Alibaba Cloud Certificate Management Service can be used.

HTTPS

HTTP

UDP

TCP

Overview
IPv6 is supported.

HTTPS

HTTP

UDP

TCP

Overview of IPv6 CLB instances
Advanced configurations can be used in forwarding rules, including custom scheduling algorithms, session persistence, and health checks.

HTTP

HTTPS

Forward requests based on domain names or URLs

August 2018

Feature Listener References
The ports and weights of multiple backend servers can be modified at a time.

HTTPS

HTTP

UDP

TCP

Add an ECS instance to the default server group

Create and manage a vServer group

July 2018

Feature Listener References
Resource quotas can be queried by calling the API.

HTTPS

HTTP

UDP

TCP

-
The console on the Alibaba Cloud China site is updated.

HTTPS

HTTP

UDP

TCP

Create and manage a CLB instance
Consistent hash algorithms are supported. The QUIC protocol and UDP session persistence are supported by Layer 4 listeners.

UDP

TCP

Add a TCP listener

Add a UDP listener

June 2018

Feature Listener References
Custom TLS versions are supported. HTTPS TLS security policies

Add an HTTPS listener

IPv6 is supported.

HTTPS

HTTP

UDP

TCP

Overview of IPv6 CLB instances

May 2018

Feature Listener References
HTTP/2 is supported. HTTPS Add an HTTPS listener
Server Name Indication (SNI) is supported to allow multiple certificates to be associated with SLB. HTTPS Configure a CLB instance to serve multiple domain names over HTTPS
Blacklists and whitelists can be configured to enforce access control.

HTTPS

HTTP

UDP

TCP

Overview

Enable access control

Access logs are supported.

HTTP

HTTPS

Configure access logs
Backend servers can be added by specifying ENIs that are attached to ECS instances in OpenAPI Explorer.

HTTPS

HTTP

UDP

TCP

AddBackendServers

April 2018

Feature Listener References
Custom timeout periods can be specified for Layer 7 listeners.

HTTP

HTTPS

Add an HTTP listener

Add an HTTPS listener

February 2018

Feature Listener References
The WS and WSS protocols are supported.

HTTP

HTTPS

Overview of WebSocket and WebSocket Secure
HTTP/2 is supported.

HTTPS

Add an HTTP listener

November 2017

Feature Listener References
Alibaba Cloud Security thresholds of SLB instances can be viewed.

HTTPS

HTTP

UDP

TCP

Anti-DDoS Origin (Basic Edition)
High-performance SLB instances are available.

HTTPS

HTTP

UDP

TCP

FAQ about high-performance CLB instances

August 2017

Feature Listener References
Layer 7 monitoring metrics such as QPS are supported.

HTTP

HTTPS

View monitoring data in the console
Custom timeout periods can be specified for Layer 4 listeners.

TCP

Add a TCP listener
The bandwidth of an SLB instance can be shared by its listeners.

HTTPS

HTTP

UDP

TCP

Add a TCP listener

Add a UDP listener

Add an HTTP listener

Add an HTTPS listener

February 2017

Feature Listener References
Primary/secondary server groups are supported.

UDP

TCP

Create and manage a primary/secondary server group

November 2016

Feature Listener References
HTTP headers can be added.

HTTP

HTTPS

Add an HTTP listener

Add an HTTPS listener

March 2016

Feature Listener References
Domain name-based and URL-based forwarding rules are supported.

HTTP

HTTPS

Forward requests based on domain names or URLs

December 2015

Feature Listener References
Cross-zone deployment is supported.

HTTPS

HTTP

UDP

TCP

Regions that support CLB

July 2015

Feature Listener References
HTTP health checks are supported by TCP listeners.

TCP

Add a TCP listener

April 2015

Feature Listener References
VPCs are supported.

HTTPS

HTTP

UDP

TCP

Create and manage a CLB instance

January 2015

Feature Listener References
HTTPS is supported. HTTPS Add an HTTPS listener

February 2014

Feature Listener References
SLB is released.

HTTP

TCP

CLB overview