Querying a Topic

Function

This API is used to query a topic.

URI

GET /v2/{project_id}/instances/{instance_id}/topics/{topic}

**Table 1** Path Parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Definition Project ID. For details about how to obtain it, see Obtaining a Project ID. Constraints N/A Range N/A Default Value N/A
instance_id	Yes	String	Definition Instance ID. You can call the API for querying all instances to obtain the instance ID. The instance ID is in the response body. Constraints N/A Range N/A Default Value N/A
topic	Yes	String	Topic name.

Request Parameters

None

Response Parameters

Status code: 200

**Table 2** Response body parameters
Parameter	Type	Description
name	String	Definition Topic name. Range N/A
total_read_queue_num	Number	Definition Total number of read queues. Range N/A
total_write_queue_num	Number	Definition Total number of write queues. Range N/A
permission	String	Definition Permission. Range sub: subscribe permissions. pub: publish permissions. all: subscribe and publish permissions.
brokers	Array of brokers objects	Definition Associated broker.
message_type	String	Definition Message type (available only for RocketMQ 5.x instances). Range NORMAL: normal messages. FIFO: ordered messages. DELAY: scheduled messages. TRANSACTION: transactional messages.

**Table 3** brokers
Parameter	Type	Description
broker_name	String	Definition Broker name. Range N/A
read_queue_num	Number	Definition Number of read queues. Range N/A
write_queue_num	Number	Definition Number of write queues. Range N/A

Example Requests

Querying details about a specified topic

GET https://{endpoint}/v2/{project_id}/instances/{instance_id}/topics/{topic}

Example Responses

Status code: 200

Topic queried successfully.

{
  "name" : "topic",
  "total_read_queue_num" : 3,
  "total_write_queue_num" : 3,
  "permission" : "all",
  "brokers" : [ {
    "broker_name" : "broker-0",
    "read_queue_num" : 3,
    "write_queue_num" : 3
  } ],
  "message_type" : "NORMAL"
}