Subscription operations - DataHub - Alibaba Cloud Documentation Center

This topic describes how to manage subscriptions using the Go SDK of DataHub.

Create a subscription

Parameters

Name	Type	Description
projectName	string	The project name.
topicName	string	The topic name.
comment	string	The subscription comment.

Error descriptions

Class name	Error code	Description
ResourceNotFoundError	`ResourceNotFound` `NoSuchProject` `NoSuchTopic` `NoSuchShard` `NoSuchSubscription` `NoSuchConnector` `NoSuchMeteringInfo`	The requested resource does not exist. This error may occur if you send another request immediately after a Split/Merge operation.
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Code example

func createSubscription() {
    csr, err := dh.CreateSubscription(projectName, topicName, "sub comment")
    if err != nil {
        fmt.Println("create subscription failed")
        fmt.Println(err)
        return
    }
    fmt.Println("create subscription successful")
    fmt.Println(*csr)
}

Delete a subscription

Parameters

Name	Type	Description
projectName	string	The project name.
topicName	string	The topic name.
subId	string	The ID of the subscription.

Error descriptions

Class name	Error code	Description
ResourceNotFoundError	`ResourceNotFound` `NoSuchProject` `NoSuchTopic` `NoSuchShard` `NoSuchSubscription` `NoSuchConnector` `NoSuchMeteringInfo`	The requested resource does not exist. This error may occur if you send another request immediately after a Split/Merge operation.
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Code example

func delSubscription(dh datahub.DataHub, projectName, topicName string) {
    subId := "1565577384801DCN0O"
    if err := dh.DeleteSubscription(projectName, topicName, subId); err != nil {
        fmt.Println("delete subscription failed")
        return
    }
    fmt.Println("delete subscription successful")
}

Query a subscription

Parameters

Name	Type	Description
projectName	string	The project name.
topicName	string	The topic name.
subId	string	The ID of the subscription.

Response example

 type GetSubscriptionResult struct {
     SubscriptionEntry
 }

Error descriptions

Class name	Error code	Description
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Code example

func getSubscription(dh datahub.DataHub, projectName, topicName string) {
    subId := "1565577384801DCN0O"
    gs, err := dh.GetSubscription(projectName, topicName, subId)
    if err != nil {
        fmt.Println("get subscription failed")
        fmt.Println(err)
        return
    }
    fmt.Println("get subscription successful")
    fmt.Println(gs)
}

List subscriptions

Retrieve a list of subscriptions by specifying pageIndex and pageSize.

pageIndex = 1, pageSize = 10 returns subscriptions 1–10.
pageIndex = 2, pageSize = 5 returns subscriptions 6–10.

Parameters

Class name	Error code	Description
projectName	string	The project name.
topicName	string	The topic name.
pageIndex	int	The page index to start the listing from.
pageSize	int	The number of subscriptions per page.

Response example

type ListSubscriptionResult struct {
    TotalCount    int64               `json:"TotalCount"`
    Subscriptions []SubscriptionEntry `json:"Subscriptions"`
}

Error descriptions

Class name	Error code	Description
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Code example

func listSubscription(dh datahub.DataHub, projectName, topicName string) {
    pageIndex := 1
    pageSize := 5
    ls, err := dh.ListSubscription(projectName, topicName, pageIndex, pageSize)
    if err != nil {
        fmt.Println("get subscription list failed")
        fmt.Println(err)
        return
    }
    fmt.Println("get subscription list successful")
    for _, sub := range ls.Subscriptions {
        fmt.Println(sub)
    }
}

Update a subscription

Parameters

Name	Type	Description
projectName	string	The project name.
topicName	string	The topic name.
subId	string	The ID of the subscription.
comment	string	The subscription comment.

Error descriptions

Class name	Error code	Description
ResourceNotFoundError	`ResourceNotFound` `NoSuchProject` `NoSuchTopic` `NoSuchShard` `NoSuchSubscription` `NoSuchConnector` `NoSuchMeteringInfo`	The requested resource does not exist. This error may occur if you send another request immediately after a Split/Merge operation.
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Sample code

func updateSubscription(dh datahub.DataHub, projectName, topicName string) {
    subId := "1565580329258VXSY8"
    if err := dh.UpdateSubscription(projectName, topicName, subId, "new sub comment"); err != nil {
        fmt.Println("update subscription comment failed")
        fmt.Println(err)
        return
    }
    fmt.Println("update subscription comment successful")
}

Update subscription status

Parameters

Parameter	Type	Description
projectName	String	The project name.
topicName	string	The topic name.
subId	string	The ID of the subscription.
state	SubscriptionState	The desired state to apply to the subscription.

Error descriptions

Class name	Error code	Description
ResourceNotFoundError	`ResourceNotFound` `NoSuchProject` `NoSuchTopic` `NoSuchShard` `NoSuchSubscription` `NoSuchConnector` `NoSuchMeteringInfo`	The requested resource does not exist. This error may occur if you send another request immediately after a Split/Merge operation.
AuthorizationFailedError	`Unauthorized`	Failed to parse the authorization signature. Check whether the AccessKey is valid.
InvalidParameterError	`InvalidParameter` `InvalidCursor`	Invalid parameters.
DatahubClientError	-	The base class for all other exceptions.

Code example

func updateSubState(dh datahub.DataHub, projectName, topicName string) {
    subId := "1565580329258VXSY8"
    if err := dh.UpdateSubscriptionState(projectName, topicName, subId, datahub.SUB_OFFLINE); err != nil {
        fmt.Println("update subscription state failed")
        fmt.Println(err)
        return
    }
    fmt.Println("update subscription state successful")
}