Serverless App Engine:Limits of CLB

Limits

SAE uses the Layer 7 load balancing capabilities of CLB. You can configure listeners for CLB instances to implement load balancing.

You can configure settings for ALB instances in the ALB console or in the SAE console. CLB does not protect the settings that you configure for CLB instances in the SAE console, and allows you to modify the settings that are maintained by SAE in the CLB console. This may cause unintended consequences for your business. To ensure that your business on the SAE side is not affected, take note of the following limits:

• If you configure a gateway route in the SAE console, SAE creates a listener or a vServer group for the gateway route. The gateway routing feature of SAE does not exclusively use your CLB instance.

  If you create a listener for the CLB instance in SAE, you can create, configure, and maintain listeners on the CLB instance in the CLB console. These operations are valid.

• The gateway routing feature of SAE also allows you to create a vServer group that can be associated with a listener. You have full permissions to manage the vServer group.
• We recommend that you do not modify or reference the listeners or vServer groups that are created by SAE. Otherwise, your business is affected. If you want to modify the listeners or vServer groups that are created by SAE, check the validity of the operations that you want to perform. The following table describes the validity of common operations.

  Type	Item	Validity	Description
  Instance	Instance name	Y	None.
  	Instance tag	-	Do not perform the following operations: Modify the tags that are created by SAE. Delete the tags that are created by SAE.
  	Elastic IP address (EIP) binding	Y	None.
  	Upgrade or downgrade	Y	None.
  	Bandwidth	Y	None.
  Listener	Listener name	N	None.
  	Bandwidth	Y	None.
  	Scheduling algorithm	Y	None.
  	vServer group ID	N	None.
  	Access control	Y	None.
  	x-forward-for request field	Y	None.
  	Gzip compression	Y	None.
  	Session persistence	Y	None.
  	Health check	Y	None.
  	Timeout period	Y	None.
  	Certificate configuration	-	You can configure or modify the main certificate only in the SAE console. Do not modify the main certificate in the CLB console. Otherwise, the configurations of the main certificate are overwritten by the configurations in SAE. You can configure multiple certificates in the CLB console. For more information, see Configure multiple HTTPS domain names and certificates in CLB.
  vServer group that is automatically created by SAE	Name	N	None.
  	Backend server (weight, instance, and port)	-	Do not delete the IP addresses that are maintained by SAE. Do not modify the port and weight of the IP addresses that are maintained by SAE. You can add the IP address of an Elastic Compute Service (ECS) instance.
  Manually created vServer group	You cannot add IP addressed that are maintained by SAE to a custom vServer group.
  Routing rule	All configuration changes	N	None.