Udi Dahan   Udi Dahan – The Software Simplist
Enterprise Development Expert & SOA Specialist
 
   
    Blog Consulting Training Articles Speaking About
  

Archive for the ‘BizTalk’ Category



BizTalk Blogs and UdiDahan.com, strange bedfellows?

Wednesday, December 19th, 2007

So, it turns out that Microsoft has quietly launched a new community-style site.

Titled "BizTalk Blogs", I wasn’t quite sure what my blog was doing there. It’s not that I never write about BizTalk – every once in a while I even find something nice to say about it :-) My quick post on BizTalk and Performance is one such example. But, let’s face it, a lot of the work I do is to provide BizTalk-like features like routing, transaction-management, and choreography (orchestration) without the actual product.

Apparently, I’m not the only non-BizTalk-only blogger there.

Including such names as Christian Weyer and Michelle Leroux Bustamante , there is a veritable who’s who in the Microsoft Connected Systems ecosystem and, quite frankly, I’m surprised the bouncer let me in the door.

So, this post is for my readers who, like me, have pretty much ignored anything looking like BizTalk for the past few years. Don’t let the name fool you. BizTalk Blogs is a valuable resource even for people who don’t care about BizTalk – and hey, you might even like what you start hearing about the future directions Microsoft is taking it.

But that’s enough of that. We’ll be back with your regularly scheduled BizTalk bashing right after this break…



NServiceBus Distributed Topology Q&A

Saturday, August 25th, 2007

I’ve been receiving more and more questions about how NServiceBus fits in distributed systems and wanted to share them:

My question is about distributed topology.

The EAI-hub-and-spoke model is all about the central server. It’s useful sometimes, but there are a lot of reasons why I’m not gung-ho on using a hub as the center of the integration universe.

The ESB distributed model puts code on the endpoints. That code solves some of the messaging problems that apps face, so that apps don’t have to face them. It also solves some of the messaging problems that enterprises face, so that enterprises don’t have to face them. (I need both).

Those problems include simple coding and deployment model, pub-sub routing, reliable transport, simple transformation, and orchestration. I wonder which of these you can do in your tool, and which you are planning to do.

I’m also interested in management. How do you insure that the endpoints are correctly configured? Do you have a central configuration store? How do you propagate changes from the center to the messaging endpoints?

And here’s my response:

The important parts of NServiceBus that are independent of the distributed topology are the API and the connection to long-running workflow. This code is indeed on the endpoint. However, if you wanted to you could easily connect to something like BizTalk and do whatever you wanted there. This general idea though is to support the ESB distributed model since there’s no such things as a centralized ESB.

In terms of the capabilities you’ve mentioned, I’ve seen developers pick up the coding model in a day or two. The deployment model is just a bunch of DLLs you deploy with each endpoint. Dependency Injection is supported by www.SpringFramework.net but you can replace that with something else easily as another implementation of the ObjectBuilder interfaces.

Currently pub/sub routing is supported over regular point-to-point transports in a transport agnostic way. You also have the ability to have subscriptions be persisted so that even if a server restarts (and clients don’t, and can’t know about that) all the subscriptions will be remembered.

The reliable transport that is currently supported is MSMQ, with the option of defining per-message type if you want durable messaging (using the [Recoverable] attribute).

In terms of orchestration you get a nice model for long-running workflow that gets kicked off by messages decorated with the [StartsWorkflow] attribute, and messages that implement the IWorkflowMessage interface get automatically routed to the persistent workflow instance. You have the ability to change the storage of workflow instances easily as well. Workflows are simple classes which are easily unit-testable in that they expose a “void Handle(T message);” method for every message type (T) that is involved in the workflow.

I haven’t done anything in terms of simple transformation yet but am currently looking for the right place in the message processing pipeline to put it. I also haven’t done anything yet in terms of management.

What is currently being done management-wise on the projects that use it are the commercial options for managing configuration files in distributed environments coupled with the regular ability to restart windows services and IIS applications. I haven’t seen anything lacking in that solution yet.


If you have any questions, please don’t hesitate to send them my way – NServiceBus@UdiDahan.com.



No such thing as a centralized ESB

Saturday, June 30th, 2007

Via David McGhee’s Q&A with Dr. Don Ferguson, but read the whole thing.

Q: Could you tell you your thoughts or preference for a distributed or centralized ESB?

DON: there is no such thing as a centralized ESB.

This is the problem with a lot of the products that call themselves ESBs. They are centralized brokers which may be clustered for availability. But they are in no way an implementation of the Bus Architectural Pattern. Please check this before cutting a check to your vendor.

Also, understand that if you do security related things in your ESB, possibly as a part of your routing rules, that if the security infrastructure is centralized that means your ESB is too. Even if it really was distributed to begin with.

Buyer beware.



BizTalk and Performance

Wednesday, May 2nd, 2007

I know I bad-talk BizTalk a lot, but I do it somewhat tongue-in-cheek and to get a rise out of people. BizTalk is a tool, something of a swiss army knife, you know, those huge, honking ones that have everything but the kitchen sink in them. One of the main areas where BizTalk gets a bad rap is in performance and scalability. On the other hand, the number of systems that I come in to assist with performance issues, that don’t use BizTalk, is still quite large. A systematic approach is needed in all cases.

I ran into another BizTalk optimization story online that once again points out that disk IO is a good first place to look, as I wrote about in my Database performance optimization article.

In closing, you need to be aware of the full environment. For instance, in BizTalk, it’s not just about messages per second. Session contention (multiple parties hitting the same session) can just lock things up tighter than, well, a tight thing. Designing for these things “up front” can save you very costly rewrites later.



Request/Service state affinity – don’t.

Sunday, February 18th, 2007

I saw this question today on the one of the blogs I follow, and seeing that it’s a question that variations of it pop up all the time, I thought that I’d chip in with my 2 cents.

How do I store some state about the current request so that I can use it later during the same service operation?

One analysis I read came at it from a technological angle – how to do this with WCF. I want to take a look at two other angles here.

The first has to do with one interpretation of the question – in the course of handling that request, there are numerous objects involved. How can we make it so that all of them have access to the request data? From a technological perspective, the answer is simple – make it thread-static (in .net this is done by applying the ThreadStaticAttribute to it), or store it in some thread-local-storage. From a design perspective, though, things aren’t all that clear. Which property of which class contains the request data, so that we can mark it with such an attribute, or under what key is the data stored in the thread-local-storage?

What I usually do is use my “IBus” interface, which exposes a “MessageBeingHandled” thread-static property. Any object that needs state about the current request makes sure to get an instance of “IBus” injected. The classic example of objects that need this data include message handlers (implementing the “IMessageHandler” interface). For more information about this design, take a look at this.

The second interpretation looks at having that request data available to the service on subsequent invocations. Personally, I don’t like the idea of having this data in-memory on the object that serviced the original request. One reason I don’t like it is that it creates an affinity between the client and the specific server handling its requests. Those of you who know me already are expecting this…

What if the server restarts?

Will that client’s state be lost? Well, not if we persisted it somewhere durable instead of just in memory. Will we stop servicing requests from that client until the original server becomes available again? Well, if the data was durably persisted, then any server could pick it up. And this is exactly what BizTalk does. You don’t want to implement BizTalk again, do you?

I can tell that some of you are surprised to hear me say this. Such a small requirement, and already we need BizTalk? Did Udi really say that?

Well, there is another, simpler way. If what you have is some kind of back-and-forth between the client and the service, you could use the Message History pattern and pack up the previous request data into the messages being sent. Although we’re increasing the message size, we’ve made it so that any server can handle any request and have access to all the previous data without creating some sort of durable contention area within the service like a database. Another option is to look at long-running workflow to model these interactions.

Finally, when it comes to ultra-scalable systems, I strongly suggest keeping the network dumb and pushing the smarts out to the edges – the clients. If you don’t need to have one client pick up where another client left off, this could be the ultimate solution. It combines with the Message History pattern and ends up sending only the data necessary on subsequent requests, thus keeping message size to a minimum. Also, your service doesn’t have to handle the state any more making it capable of handling more concurrent clients.

State management is the heart of any distributed systems development effort. Unfortunately, there aren’t any easy answers to it, but it’s important not to gloss over it if you want to have any hope of scalability in the future. Patterns help, but eventually we have to make the tradeoffs ourselves. Just don’t go running to one product or another in the hopes that it will make everything magically better.



.Net 2.0 no big deal?

Thursday, October 5th, 2006

Jesse seems to be swallowing the Microsoft party line without missing a drop in his latest post Screw 2.0, I’m Going Straight to 3.0.

From his post:


“The 2.0 framework doesn’t really give you a massive amount of really new really cool features. There is one-click, which we probably wouldn’t use anyway, generics (which are useful as a time saver, but don’t really do much that you can’t do without them), and some other little features… but the best part about the 2.0 framework is probably the IDE/dev experience, not what customers get out of it.”

Granted, One-Click is nothing to write home about, but the runtime level additions, they just totally changed the way I write code. I’m talking about generics, anonymous methods, delegate inference, and the rest. The rest of 2.0, like the enhancements of the provider model in ASP.Net, well you would have developed the same kind of framework yourself if you were doing serious web development.

The whole 3.0 story, I’ve got to tell you, I’m pretty underwhelmed. Everybody seems to be jumping up and down about WPF, and yes, it’s new and shiny, but there still the clunkety Windows message pump in the background. No real changes in how you’re going to write multi-threaded UIs, which seem to be the real future given the rise in multi-core processing. The visual aspects of client side code in the systems I write run at around 5% of the overall effort. So the UI will look better, I dunno, 4D buttons and stuff, sorry for not falling over with enthusiasm.

And then there’s WCF. Ah, wait, no publish/subscribe. Bummer, most of my systems being asynchronous in nature are built on the pub/sub model. An OO interface for interprocess communication? Who wants it – I need a message-based interface.

Don’t forget WF – what was that for again? The main place where WF can fit my needs is for handling long-running workflows between systems, since I don’t use Biztalk. But the performance of WF doesn’t seem to fit this environment, it seems to be more suited for human workflow times.

If anything, I’d have to say that .Net 2.0 was a relatively big deal. 3.0 will probably be just as important with the runtime level enhancements like lambda expressions, extension methods, anonymous types, and implicitly typed variables. All the rest of the hyped up stuff in 3.0, I don’t really expect it to change anything in how I work today.



A broker ain’t a bus – it just ain’t

Friday, September 23rd, 2005

I’ve been perusing the PDC material and ran into one of the presentations on BizTalk 2006 where the issue of communication between several services was raised. Obviously the N-square problem was shown, and then BizTalk was introduced in the middle with all communication going to and from it. So far, so good. But then, instead of calling the rose by its name, BizTalk was called a bus.

This is a call to the architecture folks at Microsoft: If something is in the middle of all communication, it is a broker. It cannot be a bus, by definition. And don’t even get me started on the single point of failure issue.

I don’t have a problem with people marketing BizTalk as the replacement of 42, however, when the technical guys start talking, well, I expect them to tell the truth.



What I want out of Biztalk

Friday, May 27th, 2005

Give me as many of the patterns out of the EIP book as you can and make it run fast. Is that too much to ask?



BizTalk’s as fast as they come (or is that go?)

Thursday, May 5th, 2005

Aaron Skonnard is blogging quite a bit about BizTalk these days. An earlier post that caught my eye quoted Mike Woods, the Sr. Technical Product Manager on the BizTalk team:

“… Finally on performance; if you’re truly seeing 1 transaction per second then something isn’t right. The SOAP adapter and heavy use of orchestration will knock your transaction rates down. Depending on what you’re doing you should be able to get that up over a hundred Tx/sec. on a well tuned BizTalk server farm.”

Isn’t one of the major selling points of BizTalk the whole webservices thing (SOAP) and the ability to express complex workflow (orchestration)? If it can’t do these things at a high transaction rate, then why do I need it? If the logic is simple, why don’t I just hand code it? I could probably get over 100 Tx/s on a single server, let alone “a well tuned … server farm”.



   


Don't miss my best content
 
Locations of visitors to this page

Recommendations

Sam Gentile Sam Gentile, Independent WCF & SOA Expert
“Udi, one of the great minds in this area.
A man I respect immensely.”





Ian Robinson Ian Robinson, Principal Consultant at ThoughtWorks
"Your blog and articles have been enormously useful in shaping, testing and refining my own approach to delivering on SOA initiatives over the last few years. Over and against a certain 3-layer-application-architecture-blown-out-to- distributed-proportions school of SOA, your writing, steers a far more valuable course."

Shy Cohen Shy Cohen, Senior Program Manager at Microsoft
“Udi is a world renowned software architect and speaker. I met Udi at a conference that we were both speaking at, and immediately recognized his keen insight and razor-sharp intellect. Our shared passion for SOA and the advancement of its practice launched a discussion that lasted into the small hours of the night.
It was evident through that discussion that Udi is one of the most knowledgeable people in the SOA space. It was also clear why – Udi does not settle for mediocrity, and seeks to fully understand (or define) the logic and principles behind things.
Humble yet uncompromising, Udi is a pleasure to interact with.”

Karl Wannenmacher Karl Wannenmacher, Senior Lead Expert at Frequentis AG
“I have been following Udi’s blog and podcasts since 2007. I’m convinced that he is one of the most knowledgeable and experienced people in the field of SOA, EDA and large scale systems.
Udi helped Frequentis to design a major subsystem of a large mission critical system with a nationwide deployment based on NServiceBus. It was impressive to see how he took the initial architecture and turned it upside down leading to a very flexible and scalable yet simple system without knowing the details of the business domain. I highly recommend consulting with Udi when it comes to large scale mission critical systems in any domain.”

Simon Segal Simon Segal, Independent Consultant
“Udi is one of the outstanding software development minds in the world today, his vast insights into Service Oriented Architectures and Smart Clients in particular are indeed a rare commodity. Udi is also an exceptional teacher and can help lead teams to fall into the pit of success. I would recommend Udi to anyone considering some Architecural guidance and support in their next project.”

Ohad Israeli Ohad Israeli, Chief Architect at Hewlett-Packard, Indigo Division
“When you need a man to do the job Udi is your man! No matter if you are facing near deadline deadlock or at the early stages of your development, if you have a problem Udi is the one who will probably be able to solve it, with his large experience at the industry and his widely horizons of thinking , he is always full of just in place great architectural ideas.
I am honored to have Udi as a colleague and a friend (plus having his cell phone on my speed dial).”

Ward Bell Ward Bell, VP Product Development at IdeaBlade
“Everyone will tell you how smart and knowledgable Udi is ... and they are oh-so-right. Let me add that Udi is a smart LISTENER. He's always calibrating what he has to offer with your needs and your experience ... looking for the fit. He has strongly held views ... and the ability to temper them with the nuances of the situation.
I trust Udi to tell me what I need to hear, even if I don't want to hear it, ... in a way that I can hear it. That's a rare skill to go along with his command and intelligence.”

Eli Brin, Program Manager at RISCO Group
“We hired Udi as a SOA specialist for a large scale project. The development is outsourced to India. SOA is a buzzword used almost for anything today. We wanted to understand what SOA really is, and what is the meaning and practice to develop a SOA based system.
We identified Udi as the one that can put some sense and order in our minds. We started with a private customized SOA training for the entire team in Israel. After that I had several focused sessions regarding our architecture and design.
I will summarize it simply (as he is the software simplist): We are very happy to have Udi in our project. It has a great benefit. We feel good and assured with the knowledge and practice he brings. He doesn’t talk over our heads. We assimilated nServicebus as the ESB of the project. I highly recommend you to bring Udi into your project.”

Catherine Hole Catherine Hole, Senior Project Manager at the Norwegian Health Network
“My colleagues and I have spent five interesting days with Udi - diving into the many aspects of SOA. Udi has shown impressive abilities of understanding organizational challenges, and has brought the business perspective into our way of looking at services. He has an excellent understanding of the many layers from business at the top to the technical infrstructure at the bottom. He is a great listener, and manages to simplify challenges in a way that is understandable both for developers and CEOs, and all the specialists in between.”

Yoel Arnon Yoel Arnon, MSMQ Expert
“Udi has a unique, in depth understanding of service oriented architecture and how it should be used in the real world, combined with excellent presentation skills. I think Udi should be a premier choice for a consultant or architect of distributed systems.”

Vadim Mesonzhnik, Development Project Lead at Polycom
“When we were faced with a task of creating a high performance server for a video-tele conferencing domain we decided to opt for a stateless cluster with SQL server approach. In order to confirm our decision we invited Udi.

After carefully listening for 2 hours he said: "With your kind of high availability and performance requirements you don’t want to go with stateless architecture."

One simple sentence saved us from implementing a wrong product and finding that out after years of development. No matter whether our former decisions were confirmed or altered, it gave us great confidence to move forward relying on the experience, industry best-practices and time-proven techniques that Udi shared with us.
It was a distinct pleasure and a unique opportunity to learn from someone who is among the best at what he does.”

Jack Van Hoof Jack Van Hoof, Enterprise Integration Architect at Dutch Railways
“Udi is a respected visionary on SOA and EDA, whose opinion I most of the time (if not always) highly agree with. The nice thing about Udi is that he is able to explain architectural concepts in terms of practical code-level examples.”

Neil Robbins Neil Robbins, Applications Architect at Brit Insurance
“Having followed Udi's blog and other writings for a number of years I attended Udi's two day course on 'Loosely Coupled Messaging with NServiceBus' at SkillsMatter, London.

I would strongly recommend this course to anyone with an interest in how to develop IT systems which provide immediate and future fitness for purpose. An influential and innovative thought leader and practitioner in his field, Udi demonstrates and shares a phenomenally in depth knowledge that proves his position as one of the premier experts in his field globally.

The course has enhanced my knowledge and skills in ways that I am able to immediately apply to provide benefits to my employer. Additionally though I will be able to build upon what I learned in my 2 days with Udi and have no doubt that it will only enhance my future career.

I cannot recommend Udi, and his courses, highly enough.”

Nick Malik Nick Malik, Enterprise Architect at Microsoft Corporation
You are an excellent speaker and trainer, Udi, and I've had the fortunate experience of having attended one of your presentations. I believe that you are a knowledgable and intelligent man.”

Sean Farmar Sean Farmar, Chief Technical Architect at Candidate Manager Ltd
“Udi has provided us with guidance in system architecture and supports our implementation of NServiceBus in our core business application.

He accompanied us in all stages of our development cycle and helped us put vision into real life distributed scalable software. He brought fresh thinking, great in depth of understanding software, and ongoing support that proved as valuable and cost effective.

Udi has the unique ability to analyze the business problem and come up with a simple and elegant solution for the code and the business alike.
With Udi's attention to details, and knowledge we avoided pit falls that would cost us dearly.”

Børge Hansen Børge Hansen, Architect Advisor at Microsoft
“Udi delivered a 5 hour long workshop on SOA for aspiring architects in Norway. While keeping everyone awake and excited Udi gave us some great insights and really delivered on making complex software challenges simple. Truly the software simplist.”

Motty Cohen, SW Manager at KorenTec Technologies
“I know Udi very well from our mutual work at KorenTec. During the analysis and design of a complex, distributed C4I system - where the basic concepts of NServiceBus start to emerge - I gained a lot of "Udi's hours" so I can surely say that he is a professional, skilled architect with fresh ideas and unique perspective for solving complex architecture challenges. His ideas, concepts and parts of the artifacts are the basis of several state-of-the-art C4I systems that I was involved in their architecture design.”

Aaron Jensen Aaron Jensen, VP of Engineering at Eleutian Technology
Awesome. Just awesome.

We’d been meaning to delve into messaging at Eleutian after multiple discussions with and blog posts from Greg Young and Udi Dahan in the past. We weren’t entirely sure where to start, how to start, what tools to use, how to use them, etc. Being able to sit in a room with Udi for an entire week while he described exactly how, why and what he does to tackle a massive enterprise system was invaluable to say the least.

We now have a much better direction and, more importantly, have the confidence we need to start introducing these powerful concepts into production at Eleutian.”

Gad Rosenthal Gad Rosenthal, Department Manager at Retalix
“A thinking person. Brought fresh and valuable ideas that helped us in architecting our product. When recommending a solution he supports it with evidence and detail so you can successfully act based on it. Udi's support "comes on all levels" - As the solution architect through to the detailed class design. Trustworthy!”

Chris Bilson Chris Bilson, Developer at Russell Investment Group
“I had the pleasure of attending a workshop Udi led at the Seattle ALT.NET conference in February 2009. I have been reading Udi's articles and listening to his podcasts for a long time and have always looked to him as a source of advice on software architecture.
When I actually met him and talked to him I was even more impressed. Not only is Udi an extremely likable person, he's got that rare gift of being able to explain complex concepts and ideas in a way that is easy to understand.
All the attendees of the workshop greatly appreciate the time he spent with us and the amazing insights into service oriented architecture he shared with us.”

Alexey Shestialtynov Alexey Shestialtynov, Senior .Net Developer at Candidate Manager
“I met Udi at Candidate Manager where he was brought in part-time as a consultant to help the company make its flagship product more scalable. For me, even after 30 years in software development, working with Udi was a great learning experience. I simply love his fresh ideas and architecture insights.
As we all know it is not enough to be armed with best tools and technologies to be successful in software - there is still human factor involved. When, as it happens, the project got in trouble, management asked Udi to step into a leadership role and bring it back on track. This he did in the span of a month. I can only wish that things had been done this way from the very beginning.
I look forward to working with Udi again in the future.”

Christopher Bennage Christopher Bennage, President at Blue Spire Consulting, Inc.
“My company was hired to be the primary development team for a large scale and highly distributed application. Since these are not necessarily everyday requirements, we wanted to bring in some additional expertise. We chose Udi because of his blogging, podcasting, and speaking. We asked him to to review our architectural strategy as well as the overall viability of project.
I was very impressed, as Udi demonstrated a broad understanding of the sorts of problems we would face. His advice was honest and unbiased and very pragmatic. Whenever I questioned him on particular points, he was able to backup his opinion with real life examples. I was also impressed with his clarity and precision. He was very careful to untangle the meaning of words that might be overloaded or otherwise confusing. While Udi's hourly rate may not be the cheapest, the ROI is undoubtedly a deal. I would highly recommend consulting with Udi.”

Robert Lewkovich, Product / Development Manager at Eggs Overnight
“Udi's advice and consulting were a huge time saver for the project I'm responsible for. The $ spent were well worth it and provided me with a more complete understanding of nServiceBus and most importantly in helping make the correct architectural decisions earlier thereby reducing later, and more expensive, rework.”

Ray Houston Ray Houston, Director of Development at TOPAZ Technologies
“Udi's SOA class made me smart - it was awesome.

The class was very well put together. The materials were clear and concise and Udi did a fantastic job presenting it. It was a good mixture of lecture, coding, and question and answer. I fully expected that I would be taking notes like crazy, but it was so well laid out that the only thing I wrote down the entire course was what I wanted for lunch. Udi provided us with all the lecture materials and everyone has access to all of the samples which are in the nServiceBus trunk.

Now I know why Udi is the "Software Simplist." I was amazed to find that all the code and solutions were indeed very simple. The patterns that Udi presented keep things simple by isolating complexity so that it doesn't creep into your day to day code. The domain code looks the same if it's running in a single process or if it's running in 100 processes.”

Ian Cooper Ian Cooper, Team Lead at Beazley
“Udi is one of the leaders in the .Net development community, one of the truly smart guys who do not just get best architectural practice well enough to educate others but drives innovation. Udi consistently challenges my thinking in ways that make me better at what I do.”

Liron Levy, Team Leader at Rafael
“I've met Udi when I worked as a team leader in Rafael. One of the most senior managers there knew Udi because he was doing superb architecture job in another Rafael project and he recommended bringing him on board to help the project I was leading.
Udi brought with him fresh solutions and invaluable deep architecture insights. He is an authority on SOA (service oriented architecture) and this was a tremendous help in our project.
On the personal level - Udi is a great communicator and can persuade even the most difficult audiences (I was part of such an audience myself..) by bringing sound explanations that draw on his extensive knowledge in the software business. Working with Udi was a great learning experience for me, and I'll be happy to work with him again in the future.”

Adam Dymitruk Adam Dymitruk, Director of IT at Apara Systems
“I met Udi for the first time at DevTeach in Montreal back in early 2007. While Udi is usually involved in SOA subjects, his knowledge spans all of a software development company's concerns. I would not hesitate to recommend Udi for any company that needs excellent leadership, mentoring, problem solving, application of patterns, implementation of methodologies and straight out solution development.
There are very few people in the world that are as dedicated to their craft as Udi is to his. At ALT.NET Seattle, Udi explained many core ideas about SOA. The team that I brought with me found his workshop and other talks the highlight of the event and provided the most value to us and our organization. I am thrilled to have the opportunity to recommend him.”

Eytan Michaeli Eytan Michaeli, CTO Korentec
“Udi was responsible for a major project in the company, and as a chief architect designed a complex multi server C4I system with many innovations and excellent performance.”


Carl Kenne Carl Kenne, .Net Consultant at Dotway AB
“Udi's session "DDD in Enterprise apps" was truly an eye opener. Udi has a great ability to explain complex enterprise designs in a very comprehensive and inspiring way. I've seen several sessions on both DDD and SOA in the past, but Udi puts it in a completly new perspective and makes us understand what it's all really about. If you ever have a chance to see any of Udi's sessions in the future, take it!”

Avi Nehama, R&D Project Manager at Retalix
“Not only that Udi is a briliant software architecture consultant, he also has remarkable abilities to present complex ideas in a simple and concise manner, and...
always with a smile. Udi is indeed a top-league professional!”

Ben Scheirman Ben Scheirman, Lead Developer at CenterPoint Energy
“Udi is one of those rare people who not only deeply understands SOA and domain driven design, but also eloquently conveys that in an easy to grasp way. He is patient, polite, and easy to talk to. I'm extremely glad I came to his workshop on SOA.”

Scott C. Reynolds Scott C. Reynolds, Director of Software Engineering at CBLPath
“Udi is consistently advancing the state of thought in software architecture, service orientation, and domain modeling.
His mastery of the technologies and techniques is second to none, but he pairs that with a singular ability to listen and communicate effectively with all parties, technical and non, to help people arrive at context-appropriate solutions. Every time I have worked with Udi, or attended a talk of his, or just had a conversation with him I have come away from it enriched with new understanding about the ideas discussed.”

Evgeny-Hen Osipow, Head of R&D at PCLine
“Udi has helped PCLine on projects by implementing architectural blueprints demonstrating the value of simple design and code.”

Rhys Campbell Rhys Campbell, Owner at Artemis West
“For many years I have been following the works of Udi. His explanation of often complex design and architectural concepts are so cleanly broken down that even the most junior of architects can begin to understand these concepts. These concepts however tend to typify the "real world" problems we face daily so even the most experienced software expert will find himself in an "Aha!" moment when following Udi teachings.
It was a pleasure to finally meet Udi in Seattle Alt.Net OpenSpaces 2008, where I was pleasantly surprised at how down-to-earth and approachable he was. His depth and breadth of software knowledge also became apparent when discussion with his peers quickly dove deep in to the problems we current face. If given the opportunity to work with or recommend Udi I would quickly take that chance. When I think .Net Architecture, I think Udi.”

Sverre Hundeide Sverre Hundeide, Senior Consultant at Objectware
“Udi had been hired to present the third LEAP master class in Oslo. He is an well known international expert on enterprise software architecture and design, and is the author of the open source messaging framework nServiceBus. The entire class was based on discussion and interaction with the audience, and the only Power Point slide used was the one showing the agenda.
He started out with sketching a naive traditional n-tier application (big ball of mud), and based on suggestions from the audience we explored different solutions which might improve the solution. Whatever suggestions we threw at him, he always had a thoroughly considered answer describing pros and cons with the suggested solution. He obviously has a lot of experience with real world enterprise SOA applications.”

Raphaël Wouters Raphaël Wouters, Owner/Managing Partner at Medinternals
“I attended Udi's excellent course 'Advanced Distributed System Design with SOA and DDD' at Skillsmatter. Few people can truly claim such a high skill and expertise level, present it using a pragmatic, concrete no-nonsense approach and still stay reachable.”

Nimrod Peleg Nimrod Peleg, Lab Engineer at Technion IIT
“One of the best programmers and software engineer I've ever met, creative, knows how to design and implemet, very collaborative and finally - the applications he designed implemeted work for many years without any problems!

Jose Manuel Beas
“When I attended Udi's SOA Workshop, then it suddenly changed my view of what Service Oriented Architectures were all about. Udi explained complex concepts very clearly and created a very productive discussion environment where all the attendees could learn a lot. I strongly recommend hiring Udi.”

Daniel Jin Daniel Jin, Senior Lead Developer at PJM Interconnection
“Udi is one of the top SOA guru in the .NET space. He is always eager to help others by sharing his knowledge and experiences. His blog articles often offer deep insights and is a invaluable resource. I highly recommend him.”

Pasi Taive Pasi Taive, Chief Architect at Tieto
“I attended both of Udi's "UI Composition Key to SOA Success" and "DDD in Enterprise Apps" sessions and they were exceptionally good. I will definitely participate in his sessions again. Udi is a great presenter and has the ability to explain complex issues in a manner that everyone understands.”

Consult with Udi

Guest Authored Books
Chapter: Introduction to SOA    Article: The Enterprise Service Bus and Your SOA

97 Things Every Software Architect Should Know



Creative Commons License  © Copyright 2005-2009, Udi Dahan. email@UdiDahan.com    Freely hosted by Weblogs.us