Retrieving messages from a queue
The CloudQueue class in the Windows Azure Storage Client Library provides both synchronous and asynchronous methods to retrieve messages from a queue. The GetMessage() method retrieves a message from a queue while the GetMessages() method retrieves up to 32 messages at a time. GetMessages() reduces the number of storage operations used to access a queue and can improve scalability of a Windows Azure Hosted Service.
Messages retrieved in this way have a visibility timeout during which they cannot be retrieved by additional calls to the Windows Azure Queue Service. The maximum visibility timeout for a message is 2 hours and the default is 30 seconds. This visibility timeout enhances the durability of a hosted service. If a consumer fails while processing a message, then the expiration of the visibility timeout causes the message to be visible once again on the queue from which another consumer can retrieve it.
One consequence of the visibility timeout is that...
