Enable Sticky Sessions for Function Compute Instance Routing - Function Compute - Alibaba Cloud - Function Compute

Creates an explicit session resource. The system automatically generates a unique SessionID, pre-allocates a function instance, and binds it to the session. You can specify TTL and IdleTimeout. This operation applies to the HEADER_FIELD or GENERATED_COOKIE affinity types, enabling session warm-up and configuration initialization. After the call, you can include the session in InvokeFunction requests for request routing.

Try it now

Try this API in OpenAPI Explorer, no manual signing needed. Successful calls auto-generate SDK code matching your parameters. Download it with built-in credential security for local usage.

Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.
API: The API that you can call to perform the action.
Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.
Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.
- For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.
- For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.
Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.
Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

fc:CreateSession

create

*All Resource

*

None

Request syntax

POST /2023-03-30/functions/{functionName}/sessions HTTP/1.1

Path Parameters

Parameter	Type	Required	Description	Example
functionName	string	No	The name of the function for which to create the session.	my-func

Request parameters

Parameter	Type	Required	Description	Example
qualifier	string	No	The version or alias of the function to which the session belongs.	aliasName1
body	CreateSessionInput	No	The session configuration.

Response elements

Element	Type	Description	Example
	Session	The session resource information.

Examples

Success response

JSON format

{
  "sessionId": "81f70ae156904eb9b7d43e12f511fe58",
  "functionName": "functionName1",
  "sessionAffinityType": "HEADER_FIELD",
  "sessionTTLInSeconds": 21600,
  "sessionIdleTimeoutInSeconds": 1800,
  "createdTime": "2025-04-01T08:15:27Z",
  "lastModifiedTime": "2025-04-01T18:15:27Z",
  "sessionStatus": "Active",
  "containerId": "c-68999e02-16a1955c-d2a03d1ccs",
  "qualifier": "AliasName1",
  "nasConfig": {
    "groupId": 100,
    "mountPoints": [
      {
        "enableTLS": true,
        "mountDir": "/home/test",
        "serverAddr": "***-uni85.cn-hangzhou.nas.com:/"
      }
    ],
    "userId": 100
  },
  "disableSessionIdReuse": false,
  "ossMountConfig": {
    "mountPoints": [
      {
        "bucketName": "my-bucket",
        "bucketPath": "/my-dir",
        "endpoint": "http://oss-cn-shanghai.aliyuncs.com",
        "mountDir": "/mnt/dir",
        "readOnly": true
      }
    ]
  },
  "polarFsConfig": {
    "groupId": 0,
    "userId": 0,
    "mountPoints": [
      {
        "instanceId": "",
        "mountDir": "",
        "remoteDir": "",
        "readOnly": false
      }
    ]
  },
  "juiceFsConfig": {
    "mountPoints": [
      {
        "volumeName": "",
        "mountDir": "",
        "remoteDir": "",
        "token": "",
        "args": [
          ""
        ]
      }
    ],
    "envs": {
      "key": ""
    }
  },
  "enableAutoPause": false,
  "enableAutoResume": false
}

Error codes

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.