Book Image

Microsoft Azure: Enterprise Application Development

Book Image

Microsoft Azure: Enterprise Application Development

Overview of this book

Microsoft's Azure platform has proved itself to be a highly scalable and highly available platform for enterprise applications. Despite a familiar development model, there is a difference between developing for Azure and moving applications and data into the cloud. You need to be aware of how to technically implement large-scale elastic applications. In this book, the authors develop an Azure application and discuss architectural considerations and important decision points for hosting an application on Azure. This book is a fast-paced introduction to all the major features of Azure, with considerations for enterprise developers. It starts with an overview of cloud computing in general, followed by an overview of Microsoft's Azure platform, and covers Windows Azure, SQL Azure, and AppFabric, discussing them with the help of a case-study. The book guides you through setting up the tools needed for Azure development, and outlines the sample application that will be built in the later chapters. Each subsequent chapter focuses on one aspect of the Azure platform—web roles, queue storage, SQL Azure, and so on—discussing the feature in greater detail and then providing a programming example by building parts of the sample application. Important architectural and security considerations are discussed with each Azure feature. The authors cover topics that are important to enterprise development, such as transferring data from an on-premises database to SQL Azure using SSIS, securing an application using AppFabric access control, blob and table storage, and asynchronous messaging using Queue Storage. Readers will learn to leverage the use of queues and worker roles for the separation of responsibilities between web and worker roles, enabling linear scale out of an Azure application through the use of additional instances. A truly "elastic" application is one that can be scaled up or down quickly to match resources to demand as well as control costs; with the practices in this book you will achieve application elasticity.
Table of Contents (23 chapters)
Microsoft Azure: Enterprise Application Development
Credits
About the Authors
Acknowledgement
Acknowledgement
About the Reviewer
Preface
Index

The ins and outs of queues


Looking at the following diagram, we can see where Queue Storage fits in with the rest of Windows Azure:

As one of the three simple storage options, Queue Storage is created when a storage service is added to an account. The Queue Storage endpoint is listed with the others when we view a storage service, as shown here:

A single Azure account can have any number of queues. Each queue is composed of messages, each of which carries the data or processing instructions that need to be acted upon by the back-end servers (refer to the next diagram).

There is no enforced limit to the number of messages in a queue, although there is a practical limit to the number of messages we'd want stacked up at any given time. Messages with a long latency in the queue are an indication that either the back-end processes need to be further optimized, or we need to scale out some additional back-end servers.

Each message is simply an XML document, in Atom format; messages are limited...