Server group type

Yes

• Select a type for the server group.
• Example value: server type

Name

Yes

• Type a name for the server group for easy management.
• Example value: alb1group1

VPC

Yes

• Select the same VPC for the server group as the ALB instance you want to associate with.
• Example value: ALB-**-VPC2

Load balancing algorithm

Yes

• Specify an algorithm for routing traffic among backend servers in the server group.
• Example value: Weighted Round Robin (WRR). Backend servers with higher weights have more round robin times or higher round robin probability.

Health check

No

• If you enable health checks, after the server group is associated with an ALB instance, the system sends health check requests to backend servers in the server group based on the specified rule to monitor their health status. Use an existing health check template, or customize health checks by configuring health check policies for the server group.
• In this example, health checks are enabled and customized. Specific configurations are as follows:
  • Health check protocol: HTTP is selected in this example.
  • Protocol version：HTTP1.1 is selected in this example.
  • Health check method: Use GET or HEAD requests for health checks.Example value: HEAD.
  • Health check domain name: Type the domain name for health check requests. By default, the parameter is left empty, and the IP address of the backend server is used. In this example, the parameter is left empty.
  • Health check path: The default value is /. Example value: /.
  • Normal status code: The example value is 2XX. A backend server passes a health check if it returns a normal status code.
  • Response timeout: The example value is 2 seconds. A backend server fails a health check if it does not respond within 2 seconds.
  • Detection interval: The example value is 2 seconds. A health check is performed for a backend server every 2 seconds.
  • Healthy threshold: The example value is 3. A backend server must pass health checks for three consecutive times before it is declared healthy.
  • Unhealthy threshold: The example value is 3. A backend server must fail health checks for three consecutive times before it is declared unhealthy.

Session persistence

No

• With the cookie-based session persistence feature, the ALB instance can forward requests from the same client to the same backend server.
• In this example, the feature is disabled.

Description

No

• Add remarks to the server group.
• In this example, no remarks are added.

Project

No

• Projects are cloud resource management units used in Volcano Engine. You can create projects to centrally manage cloud resources.
• In this example, the parameter is left empty, indicating that the instance belongs to the default project.

Tag

No

• A tag consists of a key-value pair used to mark resources, making it easier for you to search and aggregate resources. You can select tags for your server groups, or directly enter tag keys and tag values. For more information, see Using tags to manage ALB resources.

• In this example, no tags are added to the server group.

Port

• Port range: 1–65535
• Example value: 8080 for both backend servers

Weight

• The backend server with a higher weight receives more requests.
• Default: 100. Valid values: integers from 0 through 100. A backend server assigned with the weight of 0 no longer receives new requests. Example value: 100 for both backend servers
• Weight percentage of a backend server = Weight of the backend server / Weight sum of all backend servers in the server group. Example: 100/(100+100) = 50% for both backend servers
• If you set Load balancing algorithm to Source IP Hash for the server group, the specified weight becomes invalid, and the system no longer forwards requests based on the weight specified for the backend servers.

Copy

• Copy a backend server and configure it to receive requests through another port.
• In this example, the feature is disabled.

Remove

• Remove a backend server from the server group.
• In this example, the feature is disabled.