Simple Message Queue (formerly MNS):ReceiveMessage

Authorization information

By default, you can use only an Alibaba Cloud account to call this operation. You can call this operation as a Resource Access Management (RAM) user only after you grant the required permissions to the RAM user. The following table describes the authorization information of this operation. For more information, see Permission policies and examples.

Usage notes

You can call this operation to receive a message from a queue. After a message is received, the message changes to the Inactive state. The message remains in the Inactive state within the period that is specified by the VisibilityTimeout parameter of the queue. For more information about the VisibilityTimeout parameter, see CreateQueue.

During the period that is specified by the VisibilityTimeout parameter, you must call the DeleteMessage operation to delete the message. Otherwise, the message changes to the Active state and can be consumed again after the specified period ends.

Request

A request consists of the following parts:

• Request line

  GET /queues/$queueName/messages?waitseconds=10 HTTP/1.1

• Operation-specific URI parameters

  Parameter	Type	Required	Example	Description
  waitseconds	Integer	No	0	The maximum period for which the request waits if no message is available in the queue. Unit: seconds.

  Note

  • If you specify the waitseconds parameter for the ReceiveMessage operation and no message is available in the queue, the request waits for the specified period. If you do not specify the waitseconds parameter, the system uses the PollingWaitSeconds parameter that is specified for the queue. For more information, see CreateQueue.

  • We recommend that you reduce the number of concurrent long polling requests and specify an appropriate waiting period. For more information, see Limits. Simple Message Queue (SMQ, formerly MNS) determines the maximum number of concurrent long polling requests based on the number of requests, the waiting period of requests, and the number of IP addresses. If the limit is exceeded, SMQ does not hold the request and returns the 404MessageNotExist error. In this case, you are charged based on the number of requests. To extend the limit and prevent unnecessary costs, submit a ticket.

• Operation-specific request headers

  None.

• Request body

  None.

Response

A response consists of the following parts:

• HTTP status code

  HTTP/1.1 200 OK

• Operation-specific response headers

  None.

• Response body

  The response body is in the XML format. The body and parameters of the message are returned.

  Parameter	Type	Example	Description
  MessageId	String	5F290C926D472878-2-14D9529A8FA-20000****	The ID of the message. The message ID is unique in the queue.
  ReceiptHandle	String	1-ODU4OTkzNDU5My0xNDMyNzI3ODI3LTItOA==	The receipt handle that was generated after the message was consumed. You can use the receipt handle of the message to modify or delete the message that is in the Inactive state. The receipt handle is valid before the time that is specified by the NextVisibleTime parameter.
  MessageBody	String	This is a test message	The body of the message.
  MessageBodyMD5	String	C5DD56A39F5F7BB8B3337C6D11B6****	The MD5 hash of the message body.
  EnqueueTime	Long	1250700979248	The time when the message was sent to the queue. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC.
  NextVisibleTime	Long	1250700799348	The next time when the message can be consumed. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC.
  FirstDequeueTime	Long	1250700779318	The first time when the message was consumed. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC.
  DequeueCount	Integer	1	The total number of times the message was consumed.

Examples

Sample request

GET  /queues/$queueName/messages HTTP/1.1
Host: $AccountId.mns.cn-hangzhou.aliyuncs.com
Date: Wed, 28 May 2012 22:32:00 GMT
x-mns-version: 2015-06-06
Authorization: MNS 15B4D3461F177624206A:xQE0diMbLRepdf3YB+FIEXA****

Sample success response

HTTP/1.1 200 OK
Content-Type=text/xml;charset=utf-8
Content-Length:500
x-mns-request-id:512B2A634403E52B1956****
x-mns-version: 2015-06-06

<?xml version="1.0" encoding="UTF-8"?>
<Message xmlns="http://mns.aliyuncs.com/doc/v1/">
    <MessageId>5F290C926D472878-2-14D9529A8FA-20000****</MessageId>
    <ReceiptHandle>1-ODU4OTkzNDU5My0xNDMyNzI3ODI3LTItOA==</ReceiptHandle>
    <MessageBodyMD5>C5DD56A39F5F7BB8B3337C6D11B6****</MessageBodyMD5>
    <MessageBody>This is a test message</MessageBody>
    <EnqueueTime>1250700979248</EnqueueTime>
    <NextVisibleTime>1250700799348</NextVisibleTime>
    <FirstDequeueTime>1250700779318</FirstDequeueTime >
    <DequeueCount>1</DequeueCount >
    <Priority>8</Priority>
</Message>

Error codes