An event is a data record of status changes. This topic describes the details of event parameters in EventBridge.
Event sources can publish only events that comply with the CloudEvents specification to EventBridge. For more information about the CloudEvents specification, see CloudEvents 1.0.
The following sample code provides an example of an event that an event source publishes to EventBridge:
{
"data":{
"meetingName":"swqd",
"groupId":"456",
"action":"camera_off",
"time":1590592527490,
"userId":"199525",
"meetingUUID":"hz-20864c8f-b10d-45cd-9935-884bca1b****"
},
"id":"45ef4dewdwe1-7c35-447a-bd93-fab****",
"source":"acs:aliyuncvc",
"specversion":"1.0",
"subject":"acs.aliyuncvc:cn-hangzhou:{AccountId}:215672",
"time":"2020-11-19T21:04:41+08:00",
"type":"aliyuncvc:MeetingEvent:MemberOperate",
"aliyunaccountid":"123456789098****",
"aliyunpublishtime":"2020-11-19T21:04:42.179PRC",
"aliyuneventbusname":"default",
"aliyunregionid":"cn-hangzhou",
"aliyunpublishaddr":"172.25.XX.XX"
}
The following table describes the parameters in the preceding event.
Parameter | Type | Required | Example | Description |
id | String | Yes | 45ef4dewdwe1-7c35-447a-bd93-fab**** | The event ID. The ID is the unique identifier of an event. Producers must ensure that the values of the source and id parameters are unique for each event. If the event is re-sent due to exceptions such as network errors, two events that have the same id value may be received. Receivers consider events in which the values of the source and id parameters are identical as duplicated events. When an event is routed to and processed by an event target, the system uses the ID to track the event. |
source | String | Yes | acs:aliyuncvc | The event source, which is the service that produces the event and identifies the context in which the event occurs. The value of this parameter includes information such as the type of the event source and the publishing mechanism or producing process of the event. Producers must ensure that the values of the source and id parameters are unique for each event. |
specversion | String | Yes | 1.0 | The version of the CloudEvents specification. |
type | String | Yes | aliyuncvc:MeetingEvent:MemberOperate | The event type. This parameter is related to the event source. This parameter is used to route events, query events, and implement policies. The format of this parameter is defined by the producer and includes information such as the version number. |
datacontenttype | String | No | application/json;charset=utf-8 | The content type of the data parameter. Only the application/json content type is supported. |
dataschema | URI | No | None | The format of the data parameter. |
subject | String | No | acs.aliyuncvc:cn-hangzhou:{AccountId}:215672 | The event subject. JSON data contains Alibaba Cloud Resource Names (ARNs) that identify the resources that are involved in the event. In the publish-subscribe model, a subscriber subscribes to events from an event source. However, if the source parameter contains a sub-structure, the source parameter alone is insufficient to identify the event. If the data content cannot be interpreted, the subject parameter can be used to identify the subject of the event in subscription filtering scenarios. |
time | Timestamp | No | 2020-11-19T21:04:41+08:00 | The time when the event occurred. If the event occurred at an unknown time, the producer of the event in the CloudEvents format can set the time parameter to another value such as the current time. However, all producers of the same source must set the source parameter to the same value. |
data | Struct | No |
| The event content. The value is a JSON object, which is determined by the event source that produces the event. CloudEvents may contain the context given by the event producer when the event occurs. This information is encapsulated in the data parameter. |
aliyunaccountid | String | No | 123456789098**** | The ID of the Alibaba Cloud account. This parameter is not defined in the CloudEvents specification and is added to an event after an event source publishes the event to EventBridge. |
aliyunpublishtime | Timestamp | No | 2020-11-19T21:04:42.179PRC | The time when the event was received. This parameter is not defined in the CloudEvents specification and is added to an event after an event source publishes the event to EventBridge. |
aliyuneventbusname | String | Yes | default | The name of the event bus that receives the event. This parameter is not defined in the CloudEvents specification and is added to an event after an event source publishes the event to EventBridge. |
aliyunregionid | String | No | cn-hangzhou | The region where the event was received. This parameter is not defined in the CloudEvents specification and is added to an event after an event source publishes the event to EventBridge. |
aliyunpublishaddr | String | No | 172.25.XX.XX | The IP address of the server that receives the event. This parameter is not defined in the CloudEvents specification and is added to an event after an event source publishes the event to EventBridge. |
Events that event sources publish to EventBridge are divided into the following types:
Alibaba Cloud service events
Alibaba Cloud services automatically connect to EventBridge as event sources. For information about the types of Alibaba Cloud service events that are supported by EventBridge, see Alibaba Cloud service event sources.
Custom application events
If you use your application as an event source, you must connect your application to EventBridge by using an SDK.