Function Compute:RocketMQ triggers

How it works

When you create an ApsaraMQ for RocketMQ trigger in the Function Compute console, Function Compute automatically creates event streams in EventBridge based on your trigger configuration. After the trigger is active, messages arriving in the source topic are delivered to your function — individually or in batches, depending on your batch configuration.

ApsaraMQ for RocketMQ triggers are designed for end-to-end streaming data processing scenarios.

Limits

• The ApsaraMQ for RocketMQ instance must reside in the same region as the Function Compute function.

• If the number of event streams in your account reaches the upper limit, you cannot create additional ApsaraMQ for RocketMQ triggers. For quota information, see Limits.

Prerequisites

Before you begin, ensure that you have:

• Activated EventBridge and granted the required permissions. See Activate EventBridge and grant permissions to a RAM user.

• Created an event function in Function Compute. See Create an event function.

• Activated ApsaraMQ for RocketMQ and granted the required permissions. See Activate and grant permissions on ApsaraMQ for RocketMQ.

• Created an ApsaraMQ for RocketMQ instance, topic, and group ID. See Create an instance, a topic, and a group ID.

Step 1: Create a trigger

1. Log on to the Function Compute console and go to the function details page.

2. Click the Configurations tab, then click Create Trigger on the Triggers page.

3. Configure the trigger parameters described in the following table, then click OK.

For advanced settings such as push configuration, retry policies, and dead-letter queues, see Advanced features of triggers.

Step 2: (Optional) Configure test parameters

ApsaraMQ for RocketMQ delivers messages to your function as an event array. Before sending real messages, simulate trigger events to verify your function code.

1. On the Code tab of the function details page, click the icon next to Test Function and select Configure Test Parameters.

2. In the Configure Test Parameters panel, click Create New Test Event or Modify Existing Test Event, enter a name and the event content, then click OK.

The following is a sample event payload containing two messages:

[
    {
        "id": "94ebc15f-f0db-4bbe-acce-56fb72fb****",
        "source": "RocketMQ-Function-rocketmq-trigger",
        "specversion": "1.0",
        "type": "mq:Topic:SendMessage",
        "datacontenttype": "application/json; charset=utf-8",
        "subject": "acs:mq:cn-hangzhou:164901546557****:MQ_INST_164901546557****_BXhFHryi%TopicName",
        "time": "2021-04-08T06:01:20.766Z",
        "aliyunaccountid": "164901546557****",
        "aliyunpublishtime": "2021-10-15T02:05:16.791Z",
        "aliyunoriginalaccountid": "164901546557****",
        "aliyuneventbusname": "RocketMQ-Function-rocketmq-trigger",
        "aliyunregionid": "cn-chengdu",
        "aliyunpublishaddr": "42.120.XX.XX",
        "data": {
            "topic": "TopicName",
            "systemProperties": {
                "MIN_OFFSET": "0",
                "TRACE_ON": "true",
                "MAX_OFFSET": "8",
                "MSG_REGION": "cn-hangzhou",
                "KEYS": "systemProperties.KEYS",
                "CONSUME_START_TIME": 1628577790396,
                "TAGS": "systemProperties.TAGS",
                "INSTANCE_ID": "MQ_INST_164901546557****_BXhFHryi"
            },
            "userProperties": {},
            "body": "TEST"
        }
    },
    {
        "id": "94ebc15f-f0db-4bbe-acce-56fb72fb****",
        "source": "RocketMQ-Function-rocketmq-trigger",
        "specversion": "1.0",
        "type": "mq:Topic:SendMessage",
        "datacontenttype": "application/json; charset=utf-8",
        "subject": "acs:mq:cn-hangzhou:164901546557****:MQ_INST_164901546557****_BXhFHryi%TopicName",
        "time": "2021-04-08T06:01:20.766Z",
        "aliyunaccountid": "164901546557****",
        "aliyunpublishtime": "2021-10-15T02:05:16.791Z",
        "aliyunoriginalaccountid": "164901546557****",
        "aliyuneventbusname": "RocketMQ-Function-rocketmq-trigger",
        "aliyunregionid": "cn-chengdu",
        "aliyunpublishaddr": "42.120.XX.XX",
        "data": {
            "topic": "TopicName",
            "systemProperties": {
                "MIN_OFFSET": "0",
                "TRACE_ON": "true",
                "MAX_OFFSET": "8",
                "MSG_REGION": "cn-hangzhou",
                "KEYS": "systemProperties.KEYS",
                "CONSUME_START_TIME": 1628577790396,
                "TAGS": "systemProperties.TAGS",
                "INSTANCE_ID": "MQ_INST_164901546557****_BXhFHryi"
            },
            "userProperties": {},
            "body": "TEST"
        }
    }
]

Each element in the array is a CloudEvents-formatted message. The top-level fields (id, source, specversion, and so on) follow the CloudEvents specification. For details, see Overview. The data object contains the RocketMQ message content:

Step 3: Write and test your function

After the trigger is created, write your function code and test it.

'use strict';

exports.handler = (event, context, callback) => {
  console.log("event: %s", event);
  // Parse the event parameters and process the event.
  callback(null, 'return result');
}

Test the function

Two methods are available:

Method 1: Simulate with test parameters

If you configured a test event in Step 2, click Test Function on the Code tab.

Method 2: Send a real message

Log on to the ApsaraMQ for RocketMQ console, select the topic you created, and click Send Message.

After the function runs, view the output in Real-time Logs.

What's next

• To modify or delete this trigger, see Manage triggers.

• To view the event streams created by this trigger, log on to the EventBridge console. See Overview.