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

January 2022

Feature Description Reference
Backend servers can be added to Application Load Balancer (ALB) across virtual private clouds (VPCs) in different regions. Backend servers can be specified for 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 VPC-connected backend servers to an ALB instance across regions
On-premises servers can be added to Application Load Balancer (ALB). Backend servers can be specified in 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. Connect an on-premises server to ALB

November 2021

Feature Description Reference
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 Reference
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. Introduction to ALB resource plans

Purchase an ALB resource plan

August 2021

Feature Description Reference
EIP bandwidth plans can be associated with ALB. An EIP can be associated with an ALB instance and EIP bandwidth plan when you create the ALB instance. After the EIPs are associated with an EIP bandwidth plan, the EIPs share the bandwidth of the EIP bandwidth plan. This reduces bandwidth costs. Quick start

July 2021

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

July 2019

Feature Region Listener Reference
Health checks are supported. China (Hangzhou)

China (Shanghai)

China (Qingdao)

China (Beijing)

China (Zhangjiakou)

China (Hohhot)

China (Shenzhen)

China (Chengdu)

TCP

UDP

HTTP

HTTPS

Execute a health check script
SLB overview page is available. China (Hangzhou)

China (Shanghai)

China (Qingdao)

China (Beijing)

China (Zhangjiakou)

China (Hohhot)

China (Shenzhen)

China (Chengdu)

TCP

UDP

HTTP

HTTPS

-

June 2019

Feature Region Listener Reference
UDP and TCP listeners within the same SLB instance that can listen on the same port are supported in more regions. UAE (Dubai)

Australia (Sydney)

UK (London)

Germany (Frankfurt)

US (Silicon Valley)

US (Virginia)

Indonesia (Jakarta)

Japan (Tokyo)

India (Mumbai)

Singapore (Singapore)

Malaysia (Kuala Lumpur)

China (Hong Kong)

China (Shenzhen)

China (Hohhot)

China (Qingdao)

China (Chengdu)

China (Zhangjiakou)

China (Shanghai)

TCP

UDP

Add a TCP listener

Add a UDP listener

Deletion protection can be enabled for instances. China (Hangzhou)

China (Shanghai)

China (Qingdao)

China (Beijing)

China (Zhangjiakou)

China (Hohhot)

China (Shenzhen)

China (Chengdu)

UDP

TCP

HTTP

HTTPS

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

China (Shanghai)

China (Qingdao)

China (Beijing)

China (Zhangjiakou)

China (Hohhot)

China (Shenzhen)

China (Chengdu)

UDP

TCP

HTTP

HTTPS

Add backend servers by specifying their ENIs

May 2019

Feature Region Listener Reference
A port can be listened by both a UDP and a TCP listener within the same SLB instance. UK (London)

Australia (Sydney)

UAE (Dubai)

Germany (Frankfurt)

US (Silicon Valley)

US (Virginia)

Indonesia (Jakarta)

Japan (Tokyo)

India (Mumbai)

Singapore (Singapore)

UDP

TCP

Add a TCP listener

Add a UDP listener

Elliptic curve keys are supported. UK (London) HTTPS Certificate requirements
TLS 1.3 UK (London) HTTPS Manage TLS security policies
The GET method for health checks are supported by Layer 7 listeners. India (Mumbai)

HTTPS

HTTP

Add an HTTP listener

Add an HTTPS listener

April 2019

Feature Region Listener Reference
Available resources in zones can be queried by calling the API. All regions

HTTPS

HTTP

UDP

TCP

DescribeAvailableResource
IPv6 is supported. Regions and zones that support IPv6 CLB instances

HTTPS

HTTP

UDP

TCP

Overview of IPv6 CLB instances

January 2019

Feature Region Listener Reference
Idle instance management is supported. All regions

HTTPS

HTTP

UDP

TCP

Manage idle instances

December 2018

Feature Region Listener Reference
API Inspector All regions

HTTPS

HTTP

UDP

TCP

API Inspector

November 2018

Feature Region Listener Reference
HTTP requests can be redirected to HTTPS. All regions

HTTP

Redirect HTTP requests to HTTPS

October 2018

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

HTTPS

HTTP

UDP

TCP

Add backend servers by specifying their ENIs

September 2018

Feature Region Listener Reference
Certificates provided by Alibaba Cloud Certificate Management Service can be used. All regions

HTTPS

HTTP

UDP

TCP

Certificate overview
IPv6 is supported. China (Beijing): Zone F and Zone G

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. All regions

HTTP

HTTPS

Forward requests based on domain names or URLs

August 2018

Feature Region Listener Reference
The ports and weights of multiple backend servers can be modified at a time. All regions

HTTPS

HTTP

UDP

TCP

Add a default backend server

Create a vServer group

July 2018

Feature Region Listener Reference
Resource quotas can be queried by calling the API. All regions

HTTPS

HTTP

UDP

TCP

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

HTTPS

HTTP

UDP

TCP

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

Japan (Tokyo)

Australia (Sydney)

Malaysia (Kuala Lumpur)

Indonesia (Jakarta)

Germany (Frankfurt)

US (Silicon Valley)

US (Virginia)

UAE (Dubai)

China (Hohhot)

UDP

TCP

Add a TCP listener

Add a UDP listener

June 2018

Feature Region Listener Reference
Custom TLS versions are supported. All regions HTTPS Manage TLS security policies

Add an HTTPS listener

IPv6 is supported. China (Hangzhou): Zone E and Zone F

HTTPS

HTTP

UDP

TCP

Overview of IPv6 CLB instances

May 2018

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

HTTPS

HTTP

UDP

TCP

Overview

Enable access control

Access logs are supported. All regions

HTTP

HTTPS

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

HTTPS

HTTP

UDP

TCP

AddBackendServers

April 2018

Feature Region Listener Reference
Custom timeout periods can be specified for Layer 7 listeners. All regions

HTTP

HTTPS

Add an HTTP listener

Add an HTTPS listener

February 2018

Feature Region Listener Reference
The WS and WSS protocols are supported. All regions

HTTP

HTTPS

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

HTTPS

Add an HTTP listener

November 2017

Feature Region Listener Reference
Alibaba Cloud Security thresholds of SLB instances can be viewed. All regions

HTTPS

HTTP

UDP

TCP

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

HTTPS

HTTP

UDP

TCP

FAQ about high-performance CLB instances

August 2017

Feature Region Listener Reference
Layer 7 monitoring metrics such as QPS are supported. All regions

HTTP

HTTPS

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

TCP

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

HTTPS

HTTP

UDP

TCP

Add a TCP listener

Add a UDP listener

Add an HTTP listener

Add an HTTPS listener

February 2017

Feature Region Listener Reference
Primary/secondary server groups are supported. All regions

UDP

TCP

Create a primary/secondary server group

November 2016

Feature Region Listener Reference
HTTP headers can be added. All regions

HTTP

HTTPS

Add an HTTP listener

Add an HTTPS listener

March 2016

Feature Region Listener Reference
Domain name-based and URL-based forwarding rules are supported. All regions

HTTP

HTTPS

Forward requests based on domain names or URLs

December 2015

Feature Region Listener Reference
Cross-zone deployment is supported. All regions

HTTPS

HTTP

UDP

TCP

Regions and zones that support CLB

July 2015

Feature Region Listener Reference
HTTP health checks are supported by TCP listeners. All regions

TCP

Add a TCP listener

April 2015

Feature Region Listener Reference
VPCs are supported. All regions

HTTPS

HTTP

UDP

TCP

Create a CLB instance

January 2015

Feature Region Listener Reference
HTTPS is supported. All regions HTTPS Add an HTTPS listener

February 2014

Feature Region Listener Reference
SLB is released. All regions

HTTP

TCP

Overview