Most Helpful Customer Reviews
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4 of 4 people found the following review helpful:
2.0 out of 5 stars
General web services, little on finance specifics, November 19, 2004
Given the specificity of the title I had expected to see financial web services standards covered, as well as regulatory impact of Sarbanes Oaxley and other measures. But there was little of that. What is there instead is a fairly high level walkthrough of web services standards that is reasonable well written.
This book acts as a field guide of sorts, illuminating a path but not providing enough depth to serve as a guide for implementation. Illustrations were under-used and the small amounts of code that were provided weren't given much in the way of annotation.
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2 of 4 people found the following review helpful:
3.0 out of 5 stars
minimise bandwidth usage, November 16, 2004
Watters suggests that developers should build applications that use relatively less CPU and relatively more bandwidth, to keep the network busy. He gives an example where a task takes 10 minutes to compute 1Gb of data and then takes 1 second to transmit it. So that CPU only uses its network for 1 second out of 600 seconds. He sees this as undesirable.
On the contrary. The example shows an excellent optimisation of computation versus bandwidth. You WANT this situation. Also, if you are coding that application, and you can change it so that out of every 10 minutes of computation, it takes only 0.5 seconds to transmit that data, then you should do so. That is an improvement.
In the example cited, the network is only using 0.16% of its capacity. "Idleness of 99.84% is not effective resource utilisation". He is quite correct about that. But wrong to suggest that therefore there is something wrong with that application. Rather, this lets many other computers, running instances of this application or other applications, share the network. In fact, purely from the vantage point of this application, it is good, because it helps the application scale to many instances of it on the same network.
Plus, there is also the issue of latency. Even if the application puts out data at 1Gb/s, that data takes time to reach its destination. Even at the speed of light, this gives rise to times that are often long compared to those times for onboard computation on modern CPUs. Notice also that in many realistic cases, the data has to pass through switches and routers. Adds to the latency. Furthermore, the application would typically expect a reply from where ever it is sending the data so. More delays.
Watters gives his example in the context of quoting George Gilder's law about bandwidth tripling every year. Gilder is famous for saying this, and also saying that bandwidth is effectively free and infinite (or words to that effect). But this is often misunderstood by others, who ignore latency.
All this goes to the core of the book. Web Services are fundamentally a distributed computation, often on machines at different companies, possibly separated by large distances. If you use this book to design a Web Service, it still behooves you to minimise the sizes of packets going on the net, between the different parties. And also to minimise the occasions (frequencies) on which these packets need to be sent. Both factors reduce the overall bandwidth usage and latency. Helps the scaling of your application.
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0 of 2 people found the following review helpful:
5.0 out of 5 stars
Practical approach to developing Web Services, August 1, 2005
Dr. Watters takes a practical approach at developing Web Services application - rather than theoretical conceptual approach to the topic. He approached the topic from both the J2EE and .NET programmer's point of view, and provides examples throughout the text that demonstrates both A) strengths and weaknesses of each platform for developing Web services, B) broad and yet finance-industry focused application of Web services. Examples demonstrated throughout the text are easy to follow and relate to. One example that is referred to often in the text related to checking balance of a band account and a more complicated stock trading application which the author used to demonstrate WDSL and UDDI examples.
I had read a number of books on SOA and Web services in general, but I found the "how-to" approach of this book very helpful. Not that the author does not cover the basics of Web services, but he does so with demonstrating the concepts thru code samples and workable programs throughout the chapters. Background information on how and why Web services fit into the finance industry start the book - followed by an introduction to why the current systems such as CORBA and various MOM's are not doing the job right now. He follows up with the basics of data representation: XML, DTD and XML Schema. These topics are covered very briefly, and can be skipped over.
Messaging with SOAP is an essential part of Web services. All other protocols and layers rest atop of SOAP - and messaging. Two subtopics are worth highlighting: SOAP binding with HTTP and the available software packages in .NET and Java. Later in the text, the author discusses other SOAP binding protocols such as SMTP, POP, JavaMail and IMAP. WSDL is needed to define the endpoints that represent services. Examples from the SOAP chapter are expanded to take into account WSDL and UDDI, in the chapter that follows.
Security is an important topic and much more so in the finance industry. Authentication, Authorization, Secrecy and trust are some of the requirements that Web services security protocols need to fulfill. The problem with security standard is that there are too many of them: 7 protocols that cover the security aspects of Web services to be exact. The author covers these topics as they pertain to the finance industry and follows each discussion with the appropriate example.
In about 200 or so pages, Paul covers the topic of Web services quite well. His examples are applicable to the finance industry and are very easy to follow. Even if you have read other books on Wed services, I highly recommend this book to you as it will make a very good edition to your book collection.
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