New book: Microsoft Application Architecture Guide, Second Edition

We’re happy to announce that Microsoft Application Architecture Guide, 2nd Edition (Patterns & Practices) is available now. You can buy it in hard copy via online retailers (ISBN: 9780735627109) or download it from the Microsoft Download Center.

Here’s the book’s Foreword by S. Somasegar:

Foreword

In using our own technologies to build Microsoft products, and working with customers
and partners every day, we have developed practical guidance on applying
best practices for application architecture and design patterns and principles
using our technologies. This guidance is valuable to both the developer and to
the solution architect. We have built the Microsoft Application Architecture Guide to
consolidate guidance that we have gathered from our internal practices, external
experts, customers, and others in the community in order to share it with you.

The purpose of the guide is to help solution architects and developers to design and
build applications on the Microsoft platform that are more effective, to support key
decision making at the early stages of a new project, as well as providing topic-specific
content to help architects and developers improve their existing solutions. This guidance
incorporates the contributions and reviews from more than 25 external experts and
customers.

By thinking about solutions in terms of architectural patterns and principles, quality
attributes, and crosscutting concerns, you can very quickly determine a baseline application
architecture and the relevant technologies, patterns, and guidance assets that
will help you build your solution. You can then use the guide to identify key areas of
your application architecture so you can refine them for your scenario.

The guide includes reference application architectures for common application types,
such as Web, rich client, RIA, mobile, and services applications; guidelines for quality
attributes and crosscutting concerns; and guidelines on design approaches that can
help you to design and refine your solution architecture.

We are confident that the Microsoft Application Architecture Guide 2nd Edition will help
you choose the right architecture, the right technologies, and the relevant patterns
that will help you make more effective design decisions.

Sincerely,
S. Somasegar
Senior Vice President of Developer Division
Microsoft

And here’s the Foreword Scott Guthrie contributed:

Foreword

Application architecture is a challenging topic, as evidenced by the wide variety of
books, articles, and white papers on the subject. It is still too hard for developers and
architects to understand architecture and best practice design for the Microsoft platform.
The original Application Architecture for .NET: Designing Applications and Services
guide did a great job of covering this topic, but it was written in 2002.

To deal with the many technology additions since then, J. D. Meier, David Hill,
and their team from Microsoft patterns & practices have created a new application
architecture guide to provide insightful guidance for designing applications and
services that run on the Microsoft platform based on the latest best practices and
technologies. The outcome is Microsoft Application Architecture Guide 2nd Edition, a
guide targeted to help solution architects and developers design effective applications
on the Microsoft platform. While the guide provides an overview of the .NET
Framework, the Microsoft platform, and the main technologies and capabilities
within them, it also provides platform-independent, pattern-oriented, principles based
guidance that will help you design your applications on a solid foundation.

The guide is based on a number of key architecture and design principles that provide
structure. It includes guidelines for identifying and dealing with key engineering
decisions, and an explanation of the quality attributes, crosscutting concerns, and
capabilities that shape your application architecture; such as performance, security,
scalability, manageability, deployment, communication, and more.

The guide also describes, at a meta-level, the tiers and layers that a solution architect
should consider. Each tier/layer is described in terms of its focus, function, capabilities,
common design patterns, and technologies. Using these as a backdrop, the guide
then overlays relevant principles, patterns, and practices. Finally, the guide provides
canonical application archetypes to illustrate common application types. Each
archetype is described in terms of the target scenarios, technologies, patterns, and
infrastructure it contains.

The guidance as a whole is based on the combined experience and knowledge of
Microsoft experts, Microsoft partners, customers, and others in the community. It
will help you understand our platform, choose the right architecture and the right
technologies, and build applications using proven practices and lessons learned.

Sincerely,
Scott Guthrie
Corporate Vice President of .NET Developer Platform
Microsoft

And here is the book’s Preface, by David Hill:

Preface

There is an old joke, told amongst mischievous developers, that in order to be
considered an architect you just need to answer every technical question with “it
depends”—Q: What’s the best way to implement authentication and authorization in
my solution? —A: It depends; Q: How should I implement my data access layer?—A:
It depends; Q: Which technology should I use for my solution’s UI?—A: It depends.
Q: How can I make my application scalable?—A: It depends. You get the general idea.

The truth is, of course, that it really does depend. Ultimately, every solution is
different and there are many factors, both technical and non-technical, that can
significantly affect the architecture and design of a solution at both the small and
the large scales. The role of the developer and solution architect is to balance the
(frequently contradictory) requirements and constraints imposed by the business,
the end user, the organization’s IT environment and management infrastructure, the
economic environment, and of course the technologies and tools that are used to
build the solution.

And, to make life really interesting, these requirements and constraints are constantly
evolving as new opportunities arise or as new demands are imposed on the system.
Changes to business rules or the emergence of new business areas can affect both new
and existing applications. Over time, users expect richer, more consistent and more
highly integrated user experiences. New compliance requirements might emerge. Or
new IT infrastructure technologies might appear that can reduce costs or improve
availability or scalability. And, of course new technologies, frameworks, and tools are
being released all the time with promises to reduce development costs, or to enable
scenarios that were previously difficult to implement.

Clearly, making sense of all of this and at the same time delivering an effective solution
on budget and to schedule is not an easy task. It requires that the developer or
solution architect have to account for a whole host of competing and overlapping
factors (some of which are non-technical) and strike a pragmatic balance between
them all. Trying to account for too many factors can result in over-engineered,
complex solutions that take a long time to build and nevertheless fail to deliver
on promises of improved longevity or flexibility. On the other hand, consideration
of too few factors can result in constrained, inflexible, and improvised solutions that
are difficult to evolve or that do not scale well. In other words, developers and solution
architects often have to walk the path between a “golden solution” on the one
hand, and a “point-in-time solution” on the other.

This, to me, is what application architecture is all about—it’s about using today’s
tools and technologies to create as much business value as possible whilst keeping
one eye on the requirements and constraints imposed by the business today, and one
eye looking to tomorrow to maximize ongoing value through scalability, flexibility
and maintainability. A good understanding of architectural principles and patterns
allows the developer or solution architect to understand and factor into the overall
design process the important design issues that can have a big impact on the overall
success of their solution. Armed with this knowledge, they can make more informed
decisions, better balance competing or overlapping requirements and constraints,
and make sure that the solution not only meets or exceeds its business goals but it
does so in way that is cost effective and scalable, maintainable and flexible.

You’ll notice that I refer to both developers and solution architects. I believe that
both can benefit greatly from a solid understanding of the architectural patterns
and principles outlined in this guide. Some might argue that the implementation
details are less important than the overall design. In my experience this is not the
case. Small decisions accumulate over time. Implementation-level details can have
a very large impact on the overall solution architecture and on its scalability, maintainability,
and flexibility, so a solid understanding by both developers and solution
architects is essential. In addition, a shared understanding leads to better communication
between developers and architects, which is a good thing.

This guide aims to provide an overview of the application architecture and design
principles and patterns that will help you make better decisions and build more
successful solutions. The guide is structured in a way that allows you to read it
from start to finish, or use as a reference resource so you can jump directly to the
most relevant sections. The first half of the guide is focused on generally applicable
architecture and design principles and apply to any type of solution. The last half
is focused on common application types—such as Web applications, rich client
application, or mobile applications—and describes the typical architecture and key
design considerations for each. It’s likely that your particular solution won’t map
directly to these, but they can serve to provide a baseline architecture that you can
take and evolve for your particular situation. The guide provides advice on how to
identify the key elements of your architecture so you can refine it over time.

There is a particular focus throughout the guide on developing solutions on the
Microsoft platform with the .NET Framework so the guide contains references to
articles and resources that provide details on relevant technologies and tools. You’ll
find though that the underlying principles and patterns are generally applicable to
any platform. It is also worth noting that the guide is not meant to be a complete and
comprehensive reference to every aspect of application architecture and design—that
would require either a much larger guide, or multiple volumes—so the guide aims to
provide a pragmatic overview of the most important topics along with links to more
detailed guidance or in-depth material.

The field of application architecture and design is dynamic and constantly evolving. The
foundations on which successful solutions have been built in the past will continue
to serve us well into the foreseeable future, but we should also expect that the pace
of innovation, in both technologies and new design approaches, will not decrease.
The Microsoft platform and the .NET Framework and the range of technologies and
scenarios that they support are both deep and wide, and getting deeper and wider
all the time. On the other hand, we don’t need to wait for what might be. We can
build compelling valuable solutions right now, and hopefully this guide will help
you do just that.

David Hill
patterns and practices
September 2009

Finally, here’s some more information about the guide from David.

Use it!