Best practices for asynchronous tasks

Scenarios

For more information about asynchronous tasks, see Asynchronous tasks.

Preparations

• Install Serverless Devs and dependencies

• Configure Serverless Devs

• Create a Simple Message Queue (SMQ, formerly MNS) queue. For more information, see Create a queue.

• Create a Resource Access Management (RAM) role and attach the following policy to the RAM role. You can also directly use the AliyunFCDefaultRolePolicy policy. For more information, see Create a RAM role for a trusted Alibaba Cloud service.

  {
      "Version": "1",
      "Statement": [
          {
              "Action": [
                  "fc:InvokeFunction",
                  "mns:SendMessage",
                  "mns:PublishMessage",
                  "log:*"
              ],
              "Resource": "*",
              "Effect": "Allow"
          }
      ]
  }

Procedure

1. Run the following command to clone the project:

   git clone https://github.com/awesome-fc/Stateful-Async-Invocation.git

2. Run the following command to go to the project directory:

   cd Stateful-Async-Invocation

3. Modify the s.yaml file.

   The following code snippet provides a complete example of the s.yaml file. Change the value of {accountid} to the ID of your Alibaba Cloud account, and the value of {myqueue} to the destination Simple Message Queue (formerly MNS) queue that you configured for asynchronous invocations.

   edition: 3.0.0
   name: stateful-async-inovcation-demo
   access: default
   resources:
     fc-job:
       component: fc3
       props:
         region: cn-hangzhou
         description: this is test
         handler: index.handler
         memorySize: 128
         runtime: python3
         instanceConcurrency: 1
         timeout: 60
         internetAccess: true
         role: acs:ram::{accountid}:role/aliyunfcdefaultrole
         functionName: my-fc-job
         code: ./code
         asyncInvokeConfig:
           maxAsyncEventAgeInSeconds: 172800
           maxAsyncRetryAttempts: 1
           asyncTask: true
           qualifier: LATEST
           destinationConfig:
             onSuccess:
               destination: acs:mns:cn-hangzhou:{accountid}:/queues/{myqueue}/messages
             onFailure:
               destination: acs:mns:cn-hangzhou:{accountid}:/queues/{myqueue}/messages

4. Run the following command in the project directory to deploy the function:

   sudo s deploy

   After the function is deployed, you can log on to the Function Compute console to check whether the function is created and whether the asynchronous task feature is enabled for the function.

Verify configurations

1. You can use Serverless Devs to invoke the function that is deployed in the previous step. The following sample code provides an example:

   sudo s invoke --invocation-type Async -e '{"failure":true}'

   You can view and manage asynchronous invocations in the Function Compute console. For more information, see Task management.

   Note

   To view the detailed information such as the execution logs of a function, you must configure Simple Log Service for the function. For more information, see Configure the logging feature.

2. After a function is invoked, you can go to the specified destination, if configured, to view the push records.

   In this example, an Simple Message Queue (formerly MNS) queue is specified as the destination. You can receive the messages that are pushed to the destination in the SMQ console. The following code snippet shows an example:

   {
       "timestamp": 1728465119433,
       "requestContext": {
           "requestId": "1-670648a1-15197d0b-d07710222f9d",
           "functionArn": "acs:fc:cn-hangzhou:1034354682****:functions/my-fc-job",
           "condition": "InvocationError",
           "approximateInvokeCount": 2
       },
       "requestPayload": "{\"failure\":true}",
       "responseContext": {
           "statusCode": 200,
           "functionError": "InvocationError"
       },
       "responsePayload": "{\"errorMessage\":\"Function timed out after 60 seconds (maxMemoryUsage: 8MB)\"}"
   }

   Note

   If an asynchronous invocation fails or is stopped, you can obtain information about the error in SMQ.