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Create a Server Pool

A Server Pool is a group of backend servers responsible for distributing traffic to improve performance, availability, and reliability of the service.

A default Server Pool is created automatically when you create a Load Balancer.

1. Create a Server Pool

Step 1: Go to the Load Balancer Details page by selecting the Load Balancer name in the Load Balancer Management dashboard.

Step 2: Select the Server pool tab, then click Create server pool.

Step 3: Enter the Server Pool information:

  • Server pool name: Enter a name for the Server Pool.
  • Description: Optional description.
  • Protocol: Select the protocol for connecting to backend servers — HTTP, HTTPS, PROXY, PROXYV2, TCP, or UDP.
  • Add server: Select virtual machines from the list. For each member:
    • Port: The port on which the member listens for requests.
    • Weight: Priority weight for request distribution. Members with higher weight receive more requests.

Advanced settings:

  • Algorithm: Select the load balancing algorithm:
    • Round Robin: Distributes requests to members in sequence, cycling back to the first after the last.
    • Least Connection: Forwards requests to the member with the fewest active connections.
    • Source IP: Uses a hash of the client and server IP addresses to consistently route requests to the same server.
  • Sticky session: Ensures requests from the same user always go to the same server for a period of time, maintaining session state. Select App Cookie, HTTP Cookie, or Source IP. Select None to disable. For App Cookie, also enter a Cookie name.

Health check:

Select the health check protocol based on the Server Pool protocol:

Health Monitor \ PoolHTTPHTTPSPINGSCTPTCPTLS-HELLOUDP-CONNECT
HTTPYYYNYYN
HTTPSYYYNYYN
PROXYYYYNYYN
PROXYV2YYYNYYN
SCTPYNNYYNY
TCPYYYNYYN
UDPYNNYYNY

For HTTP/HTTPS health checks, also configure:

  • Path: The path to check. Must start with /.
  • HTTP method: The HTTP method used for health check requests (GET, HEAD, CONNECT, DELETE, etc.).
  • Expected Code: The HTTP status code the backend must return to be considered healthy. Can be a single value (e.g. 200), a list (e.g. 200, 202), or a range (e.g. 200-204).

Advanced selection:

  • Max retries down: Number of consecutive failed health checks before a member is marked unhealthy. Range: 1–10. Default: 3.
  • Max retries: Number of consecutive successful health checks required to mark a member healthy. Range: 1–10. Default: 3.
  • Delay (s): Time interval between health check requests.
  • Timeout (s): Maximum wait time before a health check is considered failed.

Click Create server pool to create, or Cancel to discard.