Use BatchPeekMessage to query multiple messages without changing their state - Simple Message Queue (formerly MNS)

Peeks at multiple messages in a queue without changing their state.

Description

BatchPeekMessage retrieves up to 16 messages from a queue in a single request. This operation is non-destructive -- messages remain in the Active state and are still available for other consumers to view or receive.

Unlike [BatchReceiveMessage], which moves messages to the Inactive state and hides them from other consumers for the VisibilityTimeout period, BatchPeekMessage leaves all message states unchanged.

Authorization

By default, only Alibaba Cloud accounts can call this operation. RAM users must be granted the required permissions first. For details, see Permission policies and examples.

Item	Value
API operation	BatchPeekMessage
Action	`mns:BatchPeekMessage`
Resource	`acs:mns:$region:$accountid:/queues/$queueName/messages`

Request syntax

GET /queues/$queueName/messages?peekonly=true&numOfMessages=<num> HTTP/1.1
Host: $AccountId.mns.<region>.aliyuncs.com
Date: <date>
x-mns-version: 2015-06-06
Authorization: MNS <AccessKeyId>:<Signature>

URI parameters

Parameter	Type	Required	Example	Description
peekonly	Boolean	Yes	true	Fixed to `true`. Indicates that messages are viewed without state changes.
numOfMessages	Integer	No	16	The maximum number of messages that can be viewed at a time.

Request headers

No operation-specific headers. For common headers, see [Common parameters].

Request body

None.

Response syntax

HTTP/1.1 200 OK
Content-Type: text/xml;charset=utf-8
x-mns-request-id: <request-id>
x-mns-version: 2015-06-06

<?xml version="1.0" encoding="UTF-8"?>
<Messages xmlns="http://mns.aliyuncs.com/doc/v1/">
  <Message>
    <MessageId>...</MessageId>
    <MessageBodyMD5>...</MessageBodyMD5>
    <MessageBody>...</MessageBody>
    <EnqueueTime>...</EnqueueTime>
    <FirstDequeueTime>...</FirstDequeueTime>
    <DequeueCount>...</DequeueCount>
    <Priority>...</Priority>
  </Message>
  <!-- Additional <Message> elements -->
</Messages>

Response parameters

The response body is in XML format. Each <Message> element contains the following fields:

Parameter	Type	Example	Description
MessageId	String	D6D5F7C9C12D14A4-1-14D953EFC72-20000****	Unique identifier of the message within the queue.
MessageBody	String	This is a test message.	Body of the message.
MessageBodyMD5	String	F9360F391579E71CA77BC5D50242****	MD5 hash of the message body.
EnqueueTime	Long	1250700979248	Time when the message entered the queue. UNIX timestamp in milliseconds since January 1, 1970, 00:00:00 UTC.
FirstDequeueTime	Long	1250700979348	Time when the message was first consumed. UNIX timestamp in milliseconds. Equals `EnqueueTime` if `DequeueCount` is 0.
DequeueCount	Integer	5	Total number of times the message has been consumed.
Priority	Integer	8	Priority of the message.

Examples

Sample request

GET /queues/$queueName/messages?peekonly=true&numOfMessages=16 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 response

HTTP/1.1 200 OK
Connection: close
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"?>
<Messages xmlns="http://mns.aliyuncs.com/doc/v1/">
  <Message>
    <MessageId>D6D5F7C9C12D14A4-1-14D953EFC72-20000****</MessageId>
    <MessageBodyMD5>F9360F391579E71CA77BC5D50242****</MessageBodyMD5>
    <MessageBody>This is a test message.</MessageBody>
    <EnqueueTime>1250700979248</EnqueueTime>
    <FirstDequeueTime>1250700979348</FirstDequeueTime>
    <DequeueCount>5</DequeueCount>
    <Priority>8</Priority>
  </Message>
  <Message>
    <MessageId>B4D5E8A7F23C19B5-2-15E064AFC83-30001****</MessageId>
    <MessageBodyMD5>A1B2C3D4E5F6A7B8C9D0E1F2A3B4****</MessageBodyMD5>
    <MessageBody>This is a test message.</MessageBody>
    <EnqueueTime>1250700979250</EnqueueTime>
    <FirstDequeueTime>1250700979352</FirstDequeueTime>
    <DequeueCount>5</DequeueCount>
    <Priority>8</Priority>
  </Message>
</Messages>

Error codes

Error code	Error message	HTTP status code	Description
QueueNotExist	The queue name you provided is not exist.	404	The specified queue does not exist. Verify the queue name or create the queue first.
MessageNotExist	Message not exist.	404	No visible messages exist in the queue.

Simple Message Queue (formerly MNS):BatchPeekMessage