Customer Reviews

Pattern-Oriented Software Architecture Volume 2: Patterns for Concurrent and Networked Objects

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3 star:		(3)
2 star:		(2)
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The book consists of three sections: a short introduction that outlines the problem space, a section containing a large collection of patterns, and a short final section that talks about weaving patterns into a pattern language and offers a few speculations as to the future of patterns.

The first section is quite short, but covers the problem space nicely and provides the motivation for what follows. The presentation is greatly helped by a case study for applying patterns to a concurrent web server; this illustrates how individual patterns can be used to solve particular problems and provides a practical perspective for how to make use of what is in the remainder of the book.

The second section constitutes the majority of the book and describes a large collection of network and concurrency patterns. Here is where the real meat of the book can be found, with 17 different patterns plus variants. There is something for everyone here, such as interceptor, reactor, acceptor-connector, etc. The patterns are presented clearly, with ample UML diagrams to support the extensive explanations. What I liked particularly is that the presentation is both complete and fair. For example, the double-checked locking pattern isn't just presented as a panacea for singleton initialization. Instead, you get explicit warnings about memory coherency issues, together with examples for how to deal with them, so you don't go and implement something and then wonder why it doesn't work...

The final section of the book shows how to connect patterns into a pattern language, such that each pattern nicely fits into a larger architectural whole. There is also some speculation as to where patterns might be headed next. (According to the authors, we are nowhere near having exhausted the topic.)

Overall, I was really impressed with this book. The text provides extensive references to existing literature, so if you are interested in learning about a particular topic in more detail, you'll find plenty of material for further reading. And there is an index that actually works (which is a rarity these days).

While the language is lucid, the book is probably not something you want to read in a single sitting. Instead, it's the sort of book you browse through, picking up interesting things as you go, and then referring back to them when you need more detail. (I read the book over a number of weeks, digesting a chapter at a time when it suited me.)

Overall, I highly recommend this book. While much of the content has been published previously, it's difficult to find elsewhere and not as up to date. Here, you get everything in one place, presented in a form that works both for learning and as a reference.

If you are interested in programming distributed systems, don't miss this--there is no other book that covers the ground anywhere near as well!

I highly recommend this book! If you've ever wrestled with the varying idiosyncrasies of different operating systems' APIs, the gory details of network programming and/or the complexities of multithreaded programming, then you need this book. Even if you haven't yet and are just now getting into network and concurrent programming, then you will need the tools in this book. The writing style is very very easy to read even though it is tackling a complex subject. You can tell as you read it that it was written by programmers who have been in the trenches of network and concurrent programming.

Almost as important as the patterns presented in the core of the book, are the descriptions of the challenges one faces when architecting and writing concurrent and networked software. For me, getting a clear understanding of these exact challenges and difficulties simplified the entire task of distributed programming. Add to that the patterns themselves and I feel anyone who reads this will have a great deal of confidence and competence in concurrent and networked programming.

Each pattern is clearly laid out and includes real-life examples and sample code. Additionally, there are clear descriptions of how these patterns work together to solve real problems. I was able to put the patterns described in this book into immediate use in the large-scale industrial projects that I was and still am working on. And when I say I was able to put them to use, I mean not just sparingly but rather at the very core of the architecture I was building. I can honestly say that the use of the patterns and techniques described in this book has saved me hundreds of hours of time and headache! This book takes what has been, in the past, the skill of only a few programmers and provides you with tools to tackle the complex tasks of architecting and programming concurrent and networked software.

If your intention is writing a network, concurrent application, the book is both a place to start and the best reference when trying to design your application. It explains each pattern, the context, the problems, the solutions, how to implement, why do we implement that way, examples, variants of the pattern, the advantages and the disadvantages of each pattern, how to combine the patterns together, and more. The book is very very clear and understandable (many books lacks this important feature!). One I have read the book I was able to start and implement a concurrent Server. It is very clear that without that book it was hard to do so! There is no doubt that this book makes the concurrent programming simpler for both, beginners and advanced.

First, the patterns in this book are very good. It was nice to see some coverage of low level networking patterns. As an experienced programmer, I was vaguely familiar with many of the patterns already, but it is really helpful to see the lines drawn in the sand, to hear why the authors chose to break things up as they did, and to understand the ramifications of the patterns in greater detail (eg, their clarification of the difference between Observer and Interceptor was quite helpful). I even got to learn some new patterns! (The Leader / Followers pattern was new to me.)

That said, the writing style about drove me BANANAS! I have never lost my place in a sentence when reading a book so many times. I must have read every line twice. Look, I'm a computer geek - I LOVE dense technical books, but this is something else. It's like reading Shakespear, or Charles Dickens. The authors must have been paid by the word. The specific implies the general! Have mercy! I don't need the difference between an interface and its concrete implementation belabored every time it comes up (and in a patterns book, believe me it's often!)

With so many patterns books out there written by little pikers who've probably never worked on a codebase of more than a thousand lines, this is a gust of fresh air. The first volume in this series is one of the great patterns books. The only knock I could offer on this book is that it is slanted a little toward the net equivalent of a kernel mechanic: in this day and age of the container as king, not many of us are doing thread locking on sockets (thank you Sun!<g>). That said, these are intelligent examinations of patterns that are very realistic. I just reread the section on asynchronous notification mechanisms and the trade-offs between implementing a 'double observer' and other variations and was struck by the degree to which the material had been thought through and all the logical dependencies intelligently communicated. If you want to see what patterns look like when they are in the hands of seriously bright people, not some book junk of the month JC dropout, tune in here.

This is an excellent book, but the patterns (Connector, Acceptor, Acceptor-Connector, Reactor, Proactor, Half Sync-Half Async .....) are all available in MORE expansive (yes more expansive) form on the ACE site.

Just Google "ACE Framework" and you will see Doug Schmidt and his ACE related papers section which will conveniently list all the patterns in this book plus a ton more (yes more useful patterns NOT in this book). The related papers are ALL in PDF format and can be loaded into a PDF reader (see Altrix Illiad E-Book reader) or printed out to a bind. The sites PDF editions are extensively longer and more detailed than the book editions, so you are better off going to the site instead.

These is indeed an excellent reference, but considering that most of the patterns are now implemented in ACE (see ACE Programmers Guide) or even in Java (see Java 1.5 SE and up in the java.util.concurrent for concurrency).

The books C++ Network Programming Vol 1 and Vol 2 are much better and re-visit these patterns from which you can, again, get on the site for free and in a nice color illustrated edition (PDF).

Save your $70 and visit the ACE site.

#include <review_patterns.h>

This book, it seems has the potential to go down as one of the seminal works in OOP / Patterns along with the works of GoF, Booch, Stroustrup and .... oops!! this review needs to wrap in 1000 words. sorry !

It starts with the motivations and challenges behind networked and concurrent systems and the why/how of the crisis in distributed computing. The book then focusses on 4 major realms of OO concurent and networked pgmg : Service Access and Configuration, Event Handling, Synchronization and Concurrency.

In each of these sections, 4-5 patterns are discussed in an easy format and exhaustive detail. Finally, the book talks about how multiple patterns can collaborate to form meaningful frameworks for systems [and patterns themselves] and the brief chronological rundown of the happenings in the patterns world (including taking a shot at the future <CrystalBall pattern ;-) ?>

I somehow find the style more lucid than the GoF book. Gotta say, love the CRC cards !

And oh ! There is this fantastico case study of a web server [JAWS, essentially]

If you are close to ACE/TAO or love C++ idioms or dig Patterns or writing OO message passing libraries for Linux clusters, beg borrow or steal this book. (Preferably buy ;-) [Thanks to my supportive manager to have got me this ! ]

>> Why you want to buy this <<

* Easy read, inspiring

* Detailed, very focussed. Doesn't try to be everything for everyone (and ending up as nothing for most)

* Some great C++ code / idioms [not to say that this book is incomprehensible for Java folks]

* Insight into pattern languages, collaborations and the future of patterns

* Serves as an insight into much of the architecture and rational behind ACE/TAO

* Monstrous reference section and appendices. Treasure trove !

What I would like to see in the next edition are thought-provokers, questions, exercises which will help the reader on the way forward and find out deviations from patterns.

Finally, you do not _have_ to buy this book because Knowledge is optional.

Warmest regards,

Shourya.Sarcar@geind.ge.com

I recently finished reading Pattern Oriented Software Architecture Vol 2: Patterns for Networked and Concurrent Objects. Believe it or not, it took me just one night to read this book cover to cover. The main reasons behind this are that a) the techniques described in this book are already well known to people working in a company that deals with some of the largest network applications in the world, and b) the book itself is very well written.

The really nice thing about this book is the way in which the patterns are presented. I was thoroughly impressed with how, for each pattern, the authors start with describing the problems and constraints. The solution is then presented with a static, object view. This is follwed by a dynamic view with a UML sequence diagram that shows how the pattern works at run-time. This is followed by detailed textual description of the steps required to implement the pattern, along with code snippets. Lastly, there's a list of real-world software implementations that have used the respective patterns, and one example from real life. The real life example is on occasion so instrumental in understanding the purpose and/or workings of the pattern that it could make you exclaim, "a-ha!".

Many of the patterns, like Wrapper Facade, Scoped Locking Idiom, Thread-safe Interface, Half-Sync/Half-Async, Leader/Followers, etc. are easy to follow and likely already known to people dealing with networked applications. The most insane patterns that I found were Proactor (for asynchronous demultiplexing and handling of events) and Interceptor (for event based access to the internals of a framework in a safe manner). They have the potential of making you start hating frameworks! About half of the patterns were new for me.

Builds extensively upon the foundations laid out by the previous POSA book, and Design Patterns from the notorious "Gang of Four". This is a "must have" for any serious networking and/or concurrent software engineer. Each pattern is explained in detail. Many of the patterns are presented with "real-world" analogs that help to explain the context and the solution. An excellent work, and a much needed reference in my "bag of software tools".

This is a unique book. Design philosophy, programming skills,technical details and use community support all come together in one formula. I get addicted to reading this book and playing with the code. The author is such a nice gentleman he would answer all your questions, silly or brilliant.