ALB instance upgrade

0.0.201

Starting at 00:00:00 on February 25, 2025 (UTC+8), Alibaba Cloud will upgrade Application Load Balancer (ALB) instances to provide improved application load balancing services. The upgraded ALB instances will not differentiate between IP modes. Instead, they will globally auto-scale virtual IP addresses (VIPs). After the upgrade, each ALB instance will be able to handle up to one million QPS.

Upgrade details

ALB instances created at or after 00:00:00 on February 25, 2025 (UTC+8) are upgraded versions. If you want to start using upgraded ALB instances sooner, click here to apply for the privilege. For more information about the privilege, see ALB quotas.
For non-upgraded ALB instances, Alibaba Cloud will upgrade them on the backend sometime after 00:00:00 on February 25, 2025 (UTC+8). We will notify you before the backend upgrade is performed.
There are no extra fees for this upgrade.

Main differences before and after the upgrade

Item	Before	After

Item

Before

After

IP mode

ALB instances differentiate between static IP and dynamic IP modes.

In static IP mode, the VIP used by an ALB instance is fixed. In dynamic IP mode, more VIPs can be used as the load escalates.

ALB instances no longer differentiate between IP modes. They can auto-scale VIPs as the load escalates. Each instance can handle up to one million QPS.

Health check or origin IP address of an ALB instance

An IP address in the 100.64.0.0/10 CIDR block is used, which may cause IP address conflicts in cross-region deployment scenarios.

A private IP address in the CIDR block of the vSwitch to which an ALB instance is connected is used.

Details of upgraded ALB instances

Each upgraded ALB instance is allocated with three IP addresses from the vSwitch to which the instance is connected: One acts as a VIP to provide load balancing services, and the other two as local IP addresses to communicate with backend servers and perform health checks. If a specified vSwitch does not have enough available IP addresses, an error is reported and ALB instances cannot be created. For more information about creating an ALB instance, see Create an ALB instance.
If security policies such as iptables rules are configured on your backend servers, ensure that the backend servers allow the health check IP address of an upgraded ALB instance, which is in the CIDR block of the vSwitch to which the ALB instance is connected. For information about this, see Troubleshoot ALB health check issues.
Upgraded ALB instances provide the following additional features:
- IPv6 addresses can be added to IP-type server groups, enabling them to provide both IPv4 and IPv6 backend services.
- QUIC listeners support the X-Forwarded-For header to retain the IP address of the original client that sends a request.
- Both security groups and access control lists (ACLs) can be used to filter incoming requests.
- Within the same region, SLB instances can be added to IP-type server groups, working as backend servers for ALB instances.
Upgraded ALB instances cannot be rolled back.

Contact us

This upgrade will not impact your business operations. Should you have any questions, require technical support, or need further clarification, please submit a ticket or reach out to your account manager.

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