Help Center/ FunctionGraph/ User Guide/ Configuring Functions/ Configuring Triggers/ Overview

Updated on 2025-08-19 GMT+08:00

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Overview

Introduction

Triggers are key mechanisms in FunctionGraph for initiating function execution. When other cloud services detect specific events as event sources, triggers automatically invoke the associated function based on predefined rules, enabling real-time event processing. For supported trigger events, see Supported Trigger Events.

When events reach the function, they contain only event data relevant to that trigger. This structured JSON data is converted by FunctionGraph into objects usable by the function. A single function can be configured with one or multiple triggers according to service needs. Each trigger can independently invoke the function.

Function Trigger Invocation Mode

Triggers can be invoked synchronously or asynchronously. For details about function invocation, see Invoking the Function.

Synchronous invocation: After a client invokes a function, FunctionGraph executes the function immediately and returns a response and execution result to the client.
Asynchronous invocation: After a client invokes a function, FunctionGraph queues the requests and directly returns responses to the client without waiting for the function execution result. FunctionGraph processes the queued requests one by one when the server is idle.

**Table 1** Function trigger invocation
Trigger	Invocation Mode
API Gateway (dedicated)	Synchronous. You can change it to asynchronous. For details, see Configuring Asynchronous Invocation.
API Connect (APIC)	Synchronous. You can change it to asynchronous. For details, see Configuring Asynchronous Invocation.
Timer	Synchronous (default and cannot be changed)
Cloud Trace Service (CTS)	Asynchronous (default and cannot be changed)
Document Database Service (DDS)	Asynchronous (default and cannot be changed)
Data Ingestion Service (DIS)	Asynchronous (default and cannot be changed)
DMS (for Kafka)	Asynchronous (default and cannot be changed)
Kafka (Open-Source)	Asynchronous (default and cannot be changed)
DMS (for RabbitMQ)	Asynchronous (default and cannot be changed)
GeminiDB Mongo	Asynchronous (default and cannot be changed)
Log Tank Service (LTS)	Asynchronous (default and cannot be changed)
Simple Message Notification (SMN)	Asynchronous (default and cannot be changed)
EventGrid (EG)	Asynchronous (default and cannot be changed)

Supported Trigger Events

Table 2 lists the supported cloud services and trigger events for FunctionGraph. After an event source trigger is configured, the corresponding function is automatically invoked when an event is detected.

**Table 2** Cloud service events supported by FunctionGraph
Cloud Service/Feature	Trigger Event
Timer	You can schedule a timer (timer example event) to invoke function code based on a fixed rate of minutes, hours, or days or a cron expression. For details, see Using a Timer Trigger.
APIG	FunctionGraph functions are invoked over HTTP or HTTPS by defining REST APIs and endpoints on APIG. You can map each API operation (such as, GET and PUT) to a specific function. APIG invokes the relevant function when an HTTPS request (APIG example event) is sent to the API endpoint. For details, see Using an APIG (Dedicated) Trigger.
APIC	With API operations such as GET and PUT mapped to specific functions, APIC can invoke corresponding functions to perform operations when receiving relevant HTTPS or HTTP requests. For details, see Using an APIC Trigger.
DIS	DIS can ingest large amounts of data in real time. You can create a function to automatically poll a DIS stream and process all new data records, such as website click streams, financial transactions, social media streams, IT logs, and data tracking events (DIS example event). FunctionGraph periodically polls the stream for new data records. For details, see Using a DIS Trigger.
DMS for Kafka	When a message is created in a Kafka topic, FunctionGraph consumes the message and triggers the function to perform other operations (Kafka example event)). For details about how to use Kafka triggers, see: Using a Kafka Trigger Using an Open-Source Kafka Trigger
DMS for RabbitMQ	When a DMS for RabbitMQ trigger is used, FunctionGraph periodically polls for new messages in a specific topic bound to the exchange of a RabbitMQ instance and passes the messages as input parameters to invoke functions (RabbitMQ example event). For details, see Using a DMS (for RabbitMQ) Trigger.
GeminiDB Mongo	If you create a GeminiDB Mongo trigger for a function, any updates (GeminiDB Mongo example event) to the specified database table will trigger the function. For details about how to use GeminiDB Mongo triggers, see Using a GeminiDB Mongo Trigger.
IoTDA	FunctionGraph can use IoTDA trigger to track device properties, message reporting, and status changes as well as analyze, sort out, and measure data flows (IoTDA example event). For details, see Using an IoTDA Trigger.
SMN	Simple Message Notification (SMN) sends messages to email addresses, mobile phones, or HTTP/HTTPS URLs. If you create a function with an SMN trigger, messages published to a specified topic will be passed as a parameter (SMN example event) to invoke the function. Then, the function processes the event, for example, publishing messages to other SMN topics or sending them to other cloud services. For details, see Using an SMN Trigger.
OBS	Create a function for processing OBS events, such as object creation or deletion (OBS example events). When an image is uploaded to a specified bucket, OBS invokes the function to read the image and create a thumbnail. For details, see: Using an OBS Trigger.
EG	EventGrid (EG) receives messages from event sources and passes the message payload as a parameter (EG example event) to invoke a function. Then, the function processes the events, for example, sending messages to other cloud services. EventGrid supports the following event sources: Creating an EG Trigger (OBS Application Service) Using an EG Trigger (RocketMQ custom event source) Using an EG Trigger (RabbitMQ custom event source)

Trigger Event Examples

Timer

TIMER example event. For details about the parameters, see Table 3.

{
    "version": "v2.0",
    "time": "2023-06-01T08:30:00+08:00",
    "trigger_type": "TIMER",
    "trigger_name": "Timer_001",
    "user_event": "User Event"
}

**Table 3** Parameters of a timer example event
Parameter	Category	Description
version	String	Event version
time	String	Event occurrence time, in ISO 8601 format
trigger_type	String	Trigger type
trigger_name	String	Trigger name
user_event	String	Additional information of the trigger

API Gateway (Dedicated)

API Gateway event example. For details about the parameters, see Table 4.

{
    "body": "",
    "requestContext": {
        "apiId": "bc1dcffd-aa35-474d-897c-d53425a4c08e",
        "requestId": "11cdcdcf33949dc6d722640a13091c77",
        "stage": "RELEASE"
    },
    "queryStringParameters": {
        "responseType": "html"
    },
    "httpMethod": "GET",
    "pathParameters": {},
    "headers": {
        "accept-language": "zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2",
        "accept-encoding": "gzip, deflate, br",
        "x-forwarded-port": "443",
        "x-forwarded-for": "103.218.216.98",
        "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "upgrade-insecure-requests": "1",
        "host": "50eedf92-c9ad-4ac0-827e-d7c11415d4f1.apigw.region.cloud.com",
        "x-forwarded-proto": "https",
        "pragma": "no-cache",
        "cache-control": "no-cache",
        "x-real-ip": "103.218.216.98",
        "user-agent": "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0"
    },
    "path": "/apig-event-template",
    "isBase64Encoded": true
}

**Table 4** Parameters of an APIG example event
Parameter	Category	Description
body	String	Actual request in string format
requestContext	Map	Request information, including the API gateway configuration, request ID, authentication information, and source
httpMethod	String	HTTP method
queryStringParameters	Map	Query strings configured in APIG and their actual values
pathParameters	Map	Path parameters configured in APIG and their actual values
headers	Map	Complete headers
path	String	Complete path
isBase64Encoded	Boolean	The default value is true.

Constraints:

When calling a function using APIG, isBase64Encoded is valued true by default, indicating that the request body transferred to FunctionGraph is encoded using Base64 and must be decoded for processing.

The function must return characters strings by using the following structure.

{
    "isBase64Encoded": true|false,
    "statusCode": httpStatusCode,
    "headers": {"headerName":"headerValue",...},
    "body": "..."
}

Cloud Trace Service (CTS)

DDS

DDS example event. For details about the parameters, see Table 5.

{
    "records": [
        {
            "event_source": "dds",
            "event_name": "insert",
            "region": "region",
            "event_version": "1.0",
            "dds": {
                "size_bytes": "100",
                "token": "{\"_data\": \"825D8C2F4D0000001529295A100474039A3412A64BA89041DC952357FB4446645F696400645D8C2F8E5BECCB6CF5370D6A0004\"}",
                "full_document": "{\"_id\": {\"$oid\": \"5d8c2f8e5beccb6cf5370d6a\"},\"name\": \"dds\",\"age\": {\"$numberDouble\": \"52.0\"}}",
                "ns": "{\"db\": \"functiongraph\",\"coll\": \"person\"}"
            },
            "event_source_id": "e6065860-f7b8-4cca-80bd-24ef2a3bb748"
        }
    ]
}

**Table 5** Parameters of a DDS example event
Parameter	Category	Description
region	String	Region where the DDS instance is located
event_version	String	Event version
event_source	String	Event source
event_name	String	Event name
size_bytes	Int	Message bytes
token	String	Base64-encoded data
full_document	String	Complete file information
ns	String	Column name
event_source_id	String	Event source ID

Data Ingestion Service (DIS)

DIS example event. For details about the parameters, see Table 6.

{
    "ShardID": "shardId-0000000000",
    "Message": {
        "next_partition_cursor": "eyJnZXRJdGVyYXRvclBhcmFtIjp7InN0cmVhbS1uYW1lIjoiZGlzLXN3dGVzdCIsInBhcnRpdGlvbi1pZCI6InNoYXJkSWQtMDAwMDAwMDAwMCIsImN1cnNvci10eXBlIjoiVFJJTV9IT1JJWk9OIiwic3RhcnRpbmctc2VxdWVuY2UtbnVtYmVyIjoiNCJ9LCJnZW5lcmF0ZVRpbWVzdGFtcCI6MTUwOTYwNjM5MjE5MX0",
        "records": [
            {
                "partition_key": "shardId_0000000000",
                "data": "d2VsY29tZQ==",
                "sequence_number": "0"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "dXNpbmc=",
                "sequence_number": "1"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "RnVuY3Rpb25TdGFnZQ==",
                "sequence_number": "2"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "c2VydmljZQ==",
                "sequence_number": "3"
            }
        ],
        "millis_behind_latest": ""
    },
    "Tag": "latest",
    "StreamName": "dis-swtest"
}

**Table 6** Parameters of a DIS example event
Parameter	Category	Description
ShardID	String	Partition ID
next_partition_cursor	String	Next partition cursor
Records	Map	Data records stored in a DIS stream
partition_key	String	Partition key
data	String	Data blocks, which are added by the data producer to the stream
sequence_number	Int	Record ID, which is automatically allocated by DIS
Tag	String	Stream tag
StreamName	String	Stream name

DMS (for Kafka)/Kafka (Open-Source)

Kafka example event. For details about the parameters, see Table 7.

{
    "event_version": "v1.0",
    "event_time": 1576737962,
    "trigger_type": "KAFKA",
    "region": "region",
    "instance_id": "81335d56-b9fe-4679-ba95-7030949cc76b",
    "records": [
        {
            "messages": [
                "kafka message1",
                "kafka message2",
                "kafka message3",
                "kafka message4",
                "kafka message5"
            ],
            "topic_id": "topic-test"
        }
    ]
}

**Table 7** Parameters of a Kafka example event
Parameter	Category	Description
event_version	String	Event version
event_time	String	Time when an event occurs
trigger_type	String	Event type
region	String	Region where a Kafka instance resides
instance_id	String	Kafka instance ID
messages	String	Message content
topic_id	String	Message ID

DMS (for RabbitMQ)

DMS for RabbitMQ example event. For details about the parameters, see Table 8.

{
    "event_version": "v1.0",
    "event_time": 1576737962,
    "trigger_type": "RABBITMQ",
    "region": "region",
    "records": [
        {
            "messages": [
                "rabbitmq message1",
                "rabbitmq message2",
                "rabbitmq message3",
                "rabbitmq message4",
                "rabbitmq message5"
            ],
            "instance_id": "81335d56-b9fe-4679-ba95-7030949cc76b",
            "exchange": "exchange-test"
        }
    ]
}

**Table 8** DMS for RabbitMQ parameters
Parameter	Category	Description
event_version	String	Event version
region	String	Region where a RabbitMQ instance resides
instance_id	String	RabbitMQ instance ID

GeminiDB Mongo

GeminiDB Mongo example event. For details about the parameters, see Table 9.

{
    "records": [
        {
            "event_name": "\"insert\"",
            "event_version": "1.0",
            "event_source": "gauss_mongo",
            "region": "cn-north-xx",
            "gauss_mongo": {
                "full_document": "{\"_id\": {\"$oid\":\"5f61de944778db5fcded3f87\"},\"zhangsan\": \"zhangsan\"}",
                "ns": "{\"db\": \"zhangsan\",\"coll\": \"zhangsan\"}",
                "size_bytes": "100",
                "token": "{\"_data\": \"825F61DE940000000129295A1004A2D9AE61206C43A5AF47CAF7C5C00C5946645F696400645F61DE944778DB5FCDED3F870004\"}"
            },
            "event_source_id": "51153d19-2b7d-402c-9a79-757163258a36"
        }
    ],
    "vernier": "{\"_data\": \"825F61DE940000000129295A1004A2D9AE61206C43A5AF47CAF7C5C00C5946645F696400645F61DE944778DB5FCDED3F870004\"}"
}

**Table 9** Parameters of a GeminiDB Mongo example event
Parameter	Category	Description
region	String	Region where a GeminiDB instance resides
event_source	String	Event source
event_version	String	Event version
full_document	String	Complete file information
size_bytes	Int	Message bytes
token	String	Base64-encoded data
event_source_id	String	Event source ID
vernier	String	Cursor

GeminiDB DynamoDB

IoTDA example event. For details about the parameters, see Table 10.

{
	"resource" : "device",
	"event" : "create",
	"event_time" : "20240919T011335Z",
	"event_time_ms" : "2024-09-19T01:13:35.854Z",
	"request_id" : "75127474-1a26-4578-8847-3128d6101954",
	"notify_data" : {
		"body" : {
			"app_id" : "3d40caf3ddfc4e83815b54b50f13aad7",
			"app_name" : "DefaultApp_6439vdv2",
			"device_id" : "66eb7a0ffa8d9c36870c6892_ttytytytytytyt",
			"node_id" : "ttytytytytytyt",
			"gateway_id" : "66eb7a0ffa8d9c36870c6892_ttytytytytytyt",
			"node_type" : "GATEWAY",
			"auth_info" : {
				"auth_type" : "SECRET",
				"secure_access" : false,
				"timeout" : 0
			},
			"product_id" : "66eb7a0ffa8d9c36870c6892",
			"product_name" : "test",
			"status" : "INACTIVE",
			"create_time" : "20240919T011335Z"
		}
	}
}

**Table 10** Parameters of an IoTDA example event
Parameter	Category	Description
resource	string	Data source, which includes device, device property, device message, device message status, device status, batch task, product, and device asynchronous command status and run log.
event	string	Triggering event.
event_time	string	Event triggering time in the character string format.
event_time_ms	string	Event triggering time in datetime format.
request_id	string	Request ID.
notify_data	Object. For details, see Table 11.	Message to push.

**Table 11** NotifyData
Parameter	Category	Description
body	Object. For details, see Table 12.	Message content.

**Table 12** NotifyDataBody
Parameter	Category	Description
app_id	string	Resource space ID.
app_name	string	Resource space name.
device_id	string	Device ID, used to uniquely identify a device. The value of this parameter is specified during device registration or allocated by the platform. If the value is allocated by the platform, the value is in the format of [product_id]_[node_id]. Maximum length: 256 characters
node_id	string	Device identifier. This parameter is set to the IMEI, MAC address, or serial number. Maximum length: 64 characters
gateway_id	string	Gateway ID, which is the device ID of the parent device. The gateway ID is the same as the device ID if the device is a directly connected device. If the device is an indirectly connected device, the gateway ID is the device ID of the directly connected device with which it associates.
node_type	string	Device node type.
product_id	string	Unique ID of the product associated with the device.
product_name	string	Name of the product associated with the device.
status	string	Device status. ONLINE: The device is online. OFFLINE: The device is offline. ABNORMAL: The device is abnormal. INACTIVE: The device is not activated. FREEZED: The device is frozen.
create_time	string	Time when the device was registered on the platform. The value is in the format of yyyyMMdd'T'HHmmss'Z', for example, 20151212T121212Z.
auth_info	Object. For details, see Table 13.	Access authentication information about the device.

**Table 13** AuthInfo
Parameter	Category	Description
auth_type	string	Authentication mode. Secret authentication (SECRET) and certificate authentication (CERTIFICATES) are supported. If secret authentication is used, fill in secret. If certificate authentication is used, fill in fingerprint. If auth_type is not set, secret authentication is used by default.
secure_access	Boolean	Whether the device is connected to the platform using a secure protocol. The default value is true. true: The device is connected to the platform using a secure protocol. false: The device is connected to the platform using an insecure protocol.
timeout	Integer	Validity period of the device verification code, in seconds. The default value is 0. If the device has not been connected to the platform within the validity period, the platform deletes the registration information of the device. If this parameter is set to 0, the verification code is always valid. The recommended value is 0. Note: This parameter is returned only when timeout is modified in the device registration or modification API. Minimum value: 0 Maximum value: 2147483647 Default value: 0

For details about device messages, see the IoTDA official website. For example, device addition notification.

Log Tank Service (LTS)

Simple Message Notification (SMN)

SMN example event. For details about the parameters, see Table 14.

{
    "record": [
        {
            "event_version": "1.0",
            "smn": {
                "topic_urn": "topicUrn",
                "timestamp": "2018-01-09T07:11:40Z",
                "message_attributes": null,
                "message": "this is smn message content",
                "type": "notification",
                "message_id": "a51671f77d4a479cacb09e2cd591a983",
                "subject": "this is smn message subject"
            },
            "event_subscription_urn": "functionUrn",
            "event_source": "smn"
        }
    ],
    "functionname": "test",
    "requestId": "7c307f6a-cf68-4e65-8be0-4c77405a1b2c",
    "timestamp": "Tue Jan 09 2018 15:11:40 GMT+0800 (CST)"
}

**Table 14** Parameters of an SMN example event
Parameter	Category	Description
event_version	String	Event version
topic_urn	String	Unique ID of an SMN event, which is generated by the SMN service
type	String	Event type
requestId	String	Request ID, which is generated by FunctionGraph. The ID of each request is unique.
message_id	String	Message ID, which is generated by SMN. The ID of each message is unique.
message	String	Message
event_source	String	Event source
event_subscription_urn	String	Function URN. The value is unique and can be obtained from the function details page.
timestamp	String	Time when an event occurs

Object Storage Service (OBS)

OBS example event. For details about the parameters, see Table 15.

{
    "Records": [
        {
            "eventVersion": "2.0",
            "eventTime": "2018-01-09T07:50:50.028Z",
            "requestParameters": {
                "sourceIPAddress": "103.218.216.125"
            },
            "s3": {
                "configurationId": "UK1DGFPYUKUZFHNQ00000160CC0B471D101ED30CE24DF4DB",
                "object": {
                    "eTag": "9d377b10ce778c4938b3c7e2c63a229a",
                    "sequencer": "00000000160D9E681484D6B4C0000000",
                    "key": "job.png",
                    "size": 777835
                },
                "bucket": {
                    "arn": "arn:aws:s3:::syj-input2",
                    "name": "functionstorage-template",
                    "ownerIdentity": {
                        "PrincipalId": "0ed1b73473f24134a478962e631651eb"
                    }
                }
            },
            "Region": "{region}",
            "eventName": "ObjectCreated:Post",
            "userIdentity": {
                "principalId": "9bf43789b1ff4b679040f35cc4f0dc05"
            }
        }
    ]
}

**Table 15** Parameters of an OBS example event
Parameter	Category	Description
eventVersion	String	Event version
eventTime	String	Time when an event occurs. The ISO-8601 time format is used.
sourceIPAddress	String	Source IP address
s3	Map	OBS event content
object	Map	object parameter description
bucket	Map	bucket parameter description
arn	String	Bucket ID
ownerIdentity	Map	ID of the user who creates the bucket
Region	String	Region where the bucket is located
eventName	String	Event name
userIdentity	Map	ID of the Huawei Cloud account that initiates the request

EventGrid (EG)

EG example event. For details about the parameters, see Table 16.

Custom RocketMQ event source

{
    "datacontenttype": "application/json",
    "data": {
        "context": "yyyyy"
    },
    "subject": "ROCKETMQ:region:domainId/projectId:ROCKETMQ:eventSourceName",
    "specversion": "1.0",
    "id": "016d5bd3-6231-4e9e-86ef-e451a070d598",
    "source": "eventSourceName",
    "time": "2023-04-07T11:51:10Z",
    "type": "ROCKETMQ:CloudTrace:RocketmqCall"
}

Custom RabbitMQ event source

{
"datacontenttype": "application/json",
    "data": {
        "context": "yyyyy"
    },
    "subject": "RABBITMQ:region:domainId/projectId:RABBITMQ:eventSourceName",
    "specversion": "1.0",
    "id": "016d5bd3-6231-4e9e-86ef-e451a070d598",
    "source": "eventSourceName",
    "time": "2023-04-07T11:51:10Z",
    "type": "RABBITMQ:CloudTrace:RabbitmqCall"
}

OBS application service event source

{
    "channel_id":"b65779ed-d9d0-4a6c-b312-c767226964cf",
    "description":"",
    "name":"subscription-xeak",
    "sources":[
        {
            "id":null,
            "name":"HC.OBS.DWR",
            "detail":{
                "bucket":"eventbucket",
                "objectKeyEncode":true
            },
            "filter":{
                "source":[
                    {
                        "op":"StringIn",
                        "values":[
                            "HC.OBS.DWR"
                        ]
                    }
                ],
                "type":[
                    {
                        "op":"StringIn",
                        "values":[
                            "OBS:DWR:ObjectCreated:PUT",
                            "OBS:DWR:ObjectCreated:POST"
                        ]
                    }
                ],
                "subject":{
                    "and":[
                        {
                            "op":"StringStartsWith",
                            "values":[
                                "/ddd"
                            ]
                        }
                    ]
                },
                "data":{
                    "obs":{
                        "bucket":{
                            "name":[
                                {
                                    "op":"StringIn",
                                    "values":[
                                        "output-your"
                                    ]
                                }
                            ]
                        }
                    }
                }
            },
            "provider_type":"OFFICIAL"
        }
    ],
    "targets":[
        {
            "id":null,
            "name":"HC.FunctionGraph",
            "detail":{
                "urn":"urn:fss:cn-north-7:c53626012ba84727b938ca8bf03108ef:function:A-nodejs-lqz:pylog:latest",
                "agency_name":"EG_AGENCY"
            },
            "dead_letter_queue":null,
            "provider_type":"OFFICIAL",
            "transform":{
                "type":"ORIGINAL",
                "value":""
            }
        }
    ]
}

**Table 16** Parameters of an EG example event
Parameter	Category	Description
datacontenttype	String	Data type
data	Map	Data
subject	String	Target value
specversion	String	Version
id	String	Unique key
source	String	Event source name
time	String	Subscription time
type	String	Subscription type