REST之中的幂等指的是什么？

delete_message ( **kwargs ) ¶

Deletes the specified message from the specified queue. You specify the message by using the message’s receipt handle and not the MessageId you receive when you send the message. Even if the message is locked by another reader due to the visibility timeout setting, it is still deleted from the queue. If you leave a message in the queue for longer than the queue’s configured retention period, Amazon SQS automatically deletes the message.

Note

The receipt handle is associated with a specific instance of receiving the message. If you receive a message more than once, the receipt handle you get each time you receive the message is different. If you don’t provide the most recently received receipt handle for the message when you use the DeleteMessage action, the request succeeds, but the message might not be deleted.

For standard queues, it is possible to receive a message even after you delete it. This might happen on rare occasions if one of the servers storing a copy of the message is unavailable when you send the request to delete the message. The copy remains on the server and might be returned to you on a subsequent receive request. You should ensure that your application is idempotent, so that receiving a message more than once does not cause issues.

See also: AWS API Documentation

Request Syntax

response = client.delete_message(
    QueueUrl='string',
    ReceiptHandle='string'
)

Parameters

• QueueUrl (string) –

  [REQUIRED]

  The URL of the Amazon SQS queue from which messages are deleted.

  Queue URLs are case-sensitive.

• ReceiptHandle (string) –

  [REQUIRED]

  The receipt handle associated with the message to delete.

Returns

None

PUT方法是幂等的。幂等的方法意味着请求成功执行所得到的的结果不依赖于该方法被执行的次数。