Upgrade Description

Upgrade Overview

Dedicated load balancers work better than shared load balancers. Dedicated load balancers support a wider range of protocols and can route Layer 7 requests based on advanced forwarding policies you configure. You can upgrade a shared load balancer to a dedicated load balancer.

After an upgrade is complete, the IP address and ID of the load balancer remain unchanged. Transfer Client IP Address is enabled for Layer 4 listeners and advanced forwarding enabled for Layer 7 listeners.

You can roll back upgrades as long as they are not finished. Once completed, you cannot roll back the dedicated load balancer to a shared load balancer.

Upgrade Restrictions

• Only pay-per-use shared load balancers can be upgraded.
• Only shared load balancers created on the ELB console or through API calls can be upgraded. To upgrade load balancers created using other methods, submit a service ticket.

Upgrade Impacts

You are advised to perform upgrades during off-peak hours as each upgrade may have the following impacts:

• How fast each upgrade can finish depends on how complex the load balancer is configured. In general, each upgrade takes about 5 minutes to finish.
• During an upgrade, persistent connections may be disconnected for 1 to 2 seconds. Clients can try again to establish connections with backend servers.
• During an upgrade, no operations can be performed on the load balancer and associated resources.
• A dedicated load balancer uses an IP address in its backend subnet to send requests to backend servers and verify their health.

  Make sure that the security group rules and the network ACL rules allow traffic from the backend subnet of the dedicated load balancer to the backend servers.

  For details, see Configuring Security Group Rules for Backend Servers (Dedicated Load Balancers).

• ELB monitoring data may fluctuate or be inaccurate during the upgrade. Watch your services carefully. The monitoring data will return to normal once the upgrade completes.
• If a load balancer is used by a CCE Turbo cluster, traffic to nodes will be switched to pods associated with Services or ingresses during the upgrade. This may interrupt backend services for 1 to 2 seconds.
• After an upgrade is complete, sticky sessions are applied on the dedicated load balancer, which then routes the requests from the same client to the same backend server.

Billing

• After an upgrade is complete, you will be billed based on the standard pricing of dedicated load balancers. Evaluate whether commercial discounts can be used.
• Shared load balancers can be upgraded to dedicated load balancers with elastic specifications. For their billing rules, see Billing Items (Dedicated Load Balancers).

Upgrade Precautions

• Do not upgrade shared load balancers if UDP packets are broken into smaller pieces during transmission. This could disconnect your services.
• Upgrading load balancers does not change the priorities of the existing forwarding policies. You can adjust the priorities by referring to Sorting Forwarding Policies.
• Do not modify associated cloud resources during an upgrade.