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[Article] EDA: SOA through the looking glass

Tuesday, September 29th, 2009.

Microsoft Architecture Journal

My latest article has been published in issue 21 of the Microsoft Architecture Journal:

EDA: SOA Through The Looking Glass

While event-driven architecture (EDA) is a broadly known topic, both giving up ACID integrity guarantees and introducing eventual consistency make many architects uncomfortable. Yet it is exactly these properties that can direct architectural efforts toward identifying coarsely grained business-service boundaries—services that will result in true IT-business alignment.

Business events create natural temporal boundaries across which there is no business expectation of immediate consistency or confirmation. When they are mapped to technical solutions, the loosely coupled business domains on either side of business events simply result in autonomous, loosely coupled services whose contracts explicitly reflect the inherent publish/subscribe nature of the business.

This article will describe how all of these concepts fit together, as well as how they solve thorny issues such as high availability and fault tolerance.

UPDATE: Unfortunately, Microsoft has removed a bunch of their older stuff, so I’m reposting the content here:

Download as PDF


While event-driven architecture (EDA) is a broadly known topic, both giving up ACID integrity guarantees and introducing eventual consistency make many architects uncomfortable. Yet it is exactly these properties that can direct architectural efforts toward identifying coarsely grained business-service boundaries—services that will result in true IT-business alignment.

Business events create natural temporal boundaries across which there is no business expectation of immediate consistency or confirmation. When they are mapped to technical solutions, the loosely coupled business domains on either side of business events simply result in autonomous, loosely coupled services whose contracts explicitly reflect the inherent publish/subscribe nature of the business.

This article will describe how all of these concepts fit together, as well as how they solve thorny issues such as high availability and fault tolerance.

Commands and Events

To understand the difference in nature between “classic” service- oriented architecture (SOA) and event-driven architecture (EDA), we must examine their building blocks: the command in SOA, and the event in EDA.

In the commonly used request/response communication pattern of service consumer to service provider in SOA, the request contains the action that the consumer wants to have performed (the command), and the response contains either the outcome of the action or some reaction to the expressed request, such as “action performed” and “not authorized.”

Commands are often named in imperative, present-tense form—for example, “update customer” and “cancel order.”

In EDA, the connection between event emitters and event consumers is reversed from the previously described SOA pattern. Consumers do not initiate communication in EDA; instead, they receive events that are produced by emitters. The communication is also inherently unidirectional; emitters do not depend on any response from consumers to continue performing their work.

Events are often named in passive, past-tense form—for example, “customer updated” and “order cancelled”—and can represent state changes in the domain of the emitter.

Events can be thought of as mirror images of the commands in a system. However, there might be cases in which the trigger for an event is not an explicit command, but something like a timeout.

Business Processes with Commands and Events

The difference between commands and events becomes even more pronounced as we look at each one as the building block in various business processes.

When we consider commands such as “create customer” and “create order,” we can easily understand how these commands can be combined to create more involved scenarios, such as: “When creating an order, if a customer is not provided, create a new customer.” This can be visualized as services that operate at different layers, as shown in Figure 1.

Figure 1: Commands and service orchestration

Figure 1. Commands and service orchestration

One can also understand the justification for having activity services perform all of their work transactionally, thus requiring one service to flow its transactional context into other lower-level services. This is especially important for commands that deal with the updating of data.

When working with commands, in each step of the business process, a higher-level service orchestrates the work of lower-level services.

When we try to translate this kind of orchestration behavior into events, we must consider the fact that events behave as mirror images of commands and represent our rules by using the past tense.

Instead of: “When creating an order, if a customer is not provided, create a new customer.”

We have: “When an order has been created, if a customer was not provided, create a new customer.”

It is clear that these rules are not equivalent. The first rule implies that an order should not be created unless a customer—whether provided or new—is associated with it. The second rule implies that an order can be created even if a customer has not been provided—stipulating the creation as a separate and additional activity.

To make use of EDA, it is becoming clear that we must think about our rules and processes in an event-driven way, as well as how that affects the way in which we structure and store our data.

Event-Driven Business Analysis and Database Design

When we analyze the “When an order has been created, if a customer was not provided, create a new customer” rule, we can see that a clear temporal boundary splits it up into two parts. In a system that has this rule, what we will see is that at a given point in time, an order might exist that does not have a corresponding customer. The rule also states the action that should be taken in such a scenario: the creation of a new customer. There might also be a nonfunctional requirement that states the maximum time that should be allowed for the action to be completed.

From a technical/database perspective, it might appear that we have allowed our data to get into an inconsistent state; however, that is only if we had modeled our database so that the Orders table had a non-nullable column that contained CustomerId—a foreign key to the Customers table. While such an entity-relationship design would be considered perfectly acceptable, we should consider how appropriate it really is, given the requirements of business consistency.

The rule itself indicates the business perspective of consistency; an order that has no connection to a customer is valid, for a certain period of time. Eventually, the business would like a customer to be affiliated with that order; however, the time frame around that can be strict (to a level of seconds) or quite lax (to a level of hours or days). It is also understandable that the business might want to change these time frames in cases in which it might provide a strategic advantage. An entity-relationship design that would reflect these realities would likely have a separate mapping table that connected Orders to Customers—leaving the Orders entity free of any constraint that relates to the Customers entity.

That is the important thing to understand about eventual consistency: It starts by identifying the business elements that do not have to be 100-percent, up-to-the-millisecond consistent, and then reflecting those relaxed constraints in the technical design.

In this case, we could even go so far as to have each of these transactions occur in its own database, as shown in Figure 2.

Figure 2: Event-driven data flows

Figure 2. Event-driven data flows

Benefits of Event-Driven Architecture

Given that EDA requires a rethinking of the core rules and processes of our business, the benefits of the approach must be quite substantial to make the effort worthwhile— and, indeed, they are. By looking at Figure 2, we can see very loose coupling between the two sides of the temporal boundary. Other than the structure of the event that passes from left to right, nothing is shared. Not only that, but after the event is published, the publisher no longer even needs to be online for the subscriber to process the event, so long as we use a durable transport (such as a queue).

These benefits become even more pronounced when we consider integration with other systems. Consider the case in which we want to integrate with a CRM, whether it is onsite or hosted in the cloud. In the EDA approach, if the CRM is unavailable (for whatever reason), the order will still be accepted. Contrasting this with the classic command- oriented service-composition approach, we would see there that the unavailability of the CRM would cause the entire transaction to time out and roll back. The same is true during integration of mainframes and other constrained resources: Even when they are online, they can process only N concurrent transactions (see Figure 3). Because the event publisher does not need to wait for confirmation from any subscriber, any transactions beyond those that are currently being processed by the mainframe wait patiently in the queue, without any adverse impact on the performance of order processing.

Figure 3: Load-leveling effect of queues between publishers and subscribers

Figure 3. Load-leveling effect of queues between publishers and subscribers

If all systems had to wait for confirmation from one another—as is common in the command-oriented approach—to bring one system to a level of 5 nines of availability, all of the systems that it calls would need to have the same level of availability (as would the systems that they call, recursively). While the investment in infrastructure might have business justification for one system (for example, order processing), it can be ruinous to have to multiply that level of investment across the board for nonstrategic systems (for example, shipping and billing).

In companies that are undergoing mergers or acquisitions, the ability to add a new subscriber quickly to any number of events from multiple publishers without having to change any code in those publishers is a big win (see Figure 4). This helps maintain stability of the core environment, while iteratively rolling out bridges between the systems of the two companies. When we look practically at bringing the new subscriber online, we can take the recording of all published events from the audit log and play them to the new subscriber, or perform the regular ETL style of data migration from one subscriber to another.

Figure 4: Adding new subscriber to existing publisher

Figure 4. Adding new subscriber to existing publisher

IT-Business Alignment, SOA, and EDA

One of the more profound benefits that SOA was supposed to bring was an improved alignment between IT and business. While the industry does not appear to have settled on how this exactly is supposed to occur, there is broad agreement that IT is currently not aligned with business. Often, this is described under the title of application “silos.”

To understand the core problem, let us try to visualize this lack of alignment, as shown in Figure 5.

Figure 5. Lack of IT/Business Alignment

Figure 5. Lack of IT/Business Alignment

What we see in this lack of alignment is that IT boundaries are different from business boundaries, so that it is understandable that the focus of SOA on explicit boundaries (from the four tenets of service orientation) would lead many to believe that it is the solution.

Yet the problem that we see here is while there are explicit technical boundaries between App 1 and App 2, the mapping to business boundaries is wrong.

If SOA is to have any chance of improving IT-business alignment, the connection between the two needs to look more like the one that is shown in Figure 6.

Figure 6. Services aligned with business boundaries

Figure 6. Services aligned with business boundaries

One could describe such a connection as a service “owning” or being responsible for a single business domain, so that anything outside the service could not perform any actions that relate to that domain. Also, any and all data that relates to that domain also would be accessible only within the service. The EDA model that we saw earlier enabled exactly that kind of strict separation and ownership— all the while, providing mechanisms for interaction and collaboration.

We should consider this strong connection when we look at rules such as: “When an order has been created, if a customer was not provided, create a new customer.” The creation of the order as an object or a row in a database has no significance in the business domain. From a business perspective, it could be the acceptance or the authorization of an order that matters.

What SOA brings to EDA in terms of IT-business alignment is the necessity of events to represent meaningful business occurrences.

For example, instead of thinking of an entity that is being deleted as an event, you should look for the business scenario around it— for example, a product that is being discontinued, a discount that is being revoked, or a shipment that is being canceled. Consider introducing a meaningful business status to your entities, instead of the technically common “deleted” column. While the business domain of sales will probably not be very interested in discontinued products and might treat them as deleted, the support domain might need to continue troubleshooting the problems that clients have with those products—for a while, at least. Modern-day collaborative business- analysis methodologies such as value networks can help identify these domains and the event flows between them.

What an EDA/SOA Service Looks Like

In the context of combined EDA and SOA, the word “service” is equivalent to a logical “thing” that can have a database schema, Web Services, and even user-interface (UI) code inside it. This is a very different perspective from the classic approach that considers services as just another layer of the architecture. In this context, services cut across multiple layers, as shown in Figure 7.

Figure 7. Services logically connecting code from different layers

Figure 7. Services logically connecting code from different layers

In this model, the processes that are running on various computers serve as generic, composite hosts of service code and have no real logical “meat” to them.

When we look at the code in each of the layers in light of the business domain that it addresses, we tend to see fairly tight coupling between a screen, its logic, and the data that it shows. The places in which we see loose coupling is between screens, logic, and data from different business domains; there is hardly any coupling (if at all) between the screen that shows employee details and the one that is used to cancel an order. The fact that both are screens and are categorized in the UI “layer” appears not to have much technical significance (if any business significance). Much the same can be said for the code that hooks those screens to the data, as well as the data structures themselves.

Any consistency concerns that might have arisen by this separation have already been addressed by the business acceptance of eventual consistency. If there are business demands that two pieces of data that have been allocated to different services always be consistent, this indicates that service boundaries are not aligned with business boundaries and must be changed.

This is extremely valuable. Architects can explain to the business the ramifications of their architectural decisions in ways that the business can understand—“There might be a couple of seconds during which these two bits of data are not in sync. Is that a problem?”—and the answer to those kinds of question is used to iterate the architecture, so as to bring it into better alignment with the business.

As soon as service boundaries reflect business boundaries, there is great flexibility within each service; each can change its own database schema without having to worry about breaking other services, or even choose to change vendors and technology to such things as object or XML databases. Interoperability between services is a question of how event structures are represented, as well as how publish/subscribe is handled. This can be done by using basic enterprise service bus (ESB) functionality, such things as the Atom Publishing Protocol, or a mix.

Integration of legacy applications in this environment occurs within the context of a service, instead of identifying them as services in their own right. Use of Web Services to ease the cost of integration continues to make sense; however, from the perspective of a business domain, it really is nothing more than an implementation detail.


EDA is not a technical panacea to Web Services–centric architectures. In fact, attempting to employ EDA principles on purely technical domains that implement command-centric business analysis will almost certainly fail. The introduction of eventual consistency without the ratification of business stakeholders is poorly advised.

However, if in the process of architecture we work collaboratively with the business, map out the natural boundaries that are inherent in the organization and the way in which it works, and align the boundaries of our services to them, we will find that the benefits of EDA bring substantial gains to the business in terms of greater flexibility and shorter times to market, while its apparent disadvantages become addressed in terms of additional entity statuses and finer-grained events.

By itself, EDA ignores the IT-business alignment of SOA—so critical to getting boundaries and events right. Classic SOA has largely ignored the rock-solid foundation of publish/subscribe events—dead Web Services eventing and notification standards notwithstanding. It is only in the fusing of these two approaches that they overcome the weaknesses of each other and create a whole that is greater than the sum of its parts.

Interestingly enough, even though we have almost literally turned the classic command-driven services on their heads, the service- oriented tenets of autonomy and explicit boundaries have only become more pronounced, and the goal of IT-business alignment is now within our grasp.

Beyond just being a sound theoretical foundation, this architecture has weathered the trials of production in domains such as finance, travel and hospitality, aerospace, and many others—each with its own challenging constraints and nonfunctional demands. Organizations have maximized the effectiveness of their development teams by structuring them in accordance with these same service boundaries, instead of the more common technical specialization that corresponds to layered architectures. These loosely coupled service teams were able to wring the most out of their agile methodologies, as competition for specialized shared resources was eliminated.

Oracle once named this approach SOA 2.0. Maybe it really is the next evolutionary step.

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  1. Ameer Says:

    Nice piece. Bill Poole blogged along the same lines too. As an added benefit to Business / IT alignment, this is a view of SOA that seems to put some sanity into SOA solution development because coarser grained services allows us to better leverage OO and DDD.

    I have always felt that command-based layered service architecture, as advocated by Thomas Erl and others, will ultimately impede enterprise agility by increasing the cost and risk of change.

    Hugh Taylor published a book on SOA and EDA this year, I haven’t read it yet, but the TOC suggests it supports and elaborates on the same arguments.

    Is it possible that we’re witnessing a maturer SOA being born? Something that will finally removes Fowler’s (A)mbiguity from SO(A). Should we give it its own name? Perhaps EDSOA, or maybe SOEDA!


  2. udidahan Says:


    Glad you liked it. I share your hope for a more viable SOA/EDA approach that will gain broad industry adoption.

  3. Chris Deweese Says:

    What timing! I just delivered this presentation to a government info sharing conference: http://www.slideshare.net/cdeweese/integrating-systems-with-niem-using-soa

    EDA has been milling around my head for a few months now and it clicked. I think I get it and the more I conceptualize about systems and problems I’m having I see a good fit for EDA. EDA is a much better model for the real-world, a cleaner abstraction because things don’t happen request-response or in the order you want them to. The last 35 minutes of my presentation was Q&A and there were several people doing SOA implementations saying the same thing – when you conceptualize things in events it’s a better model. You can account for all kinds of things you couldn’t before, including time. Which, in justice & LE is ever prevalent.

    There must be some sort of awesome EDA energy lighting up the web because the more people I talk to the more sense it makes. I’ve got a long way to go, but the gears are turnin.

    Keep up the great work man, it’s shaping thoughts to a better way to deal with the real-world and align business with IT!

  4. Olav Rask Says:

    Great article! One question:

    Continuing with your example of an order service and a customer service – who would hold the ordercustomer data? If a requirment was for a list of orders with associated customers to be printed (or used for some other purpose), would the printing service simply request data from both services or would this be pre-cached by listening for order and customer events?

  5. udidahan Says:


    Synchronicities abound 🙂

  6. udidahan Says:


    Glad you liked the article. To your question:

    > Who would hold the ordercustomer data?

    The sales service would hold the order data indexed by customer Id.

    Printing isn’t a service and can be thought of as a physical endpoint on which multiple services can run – each contributing the part of the data it owns.

    As a goal, we should see services not requiring each others data beyond just IDs.

    Does that answer your question?

  7. Olav Rask Says:

    I think i focused too much on data types instead of business meaning – i had my mind set on a many to many relation with meaning to both sides. It makes perfect sense that the “Sales” service would hold the order->customer information. Thinking about it, such info would not fit very well in the Customer service 🙂

    I’m not quite sure i understand the second part of your answer. Could a concrete implementetion be two services each collecting data and storing this in a common database from where reports could be generated and printed?

  8. udidahan Says:


    About the printing – no, there wouldn’t need to be a common database. Both services would be involved in the printing, as well as another layout service.

    Hope that makes sense.

  9. Olav Says:

    It does – thank you for taking the time 🙂

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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.”

Eran Sagi, Software Architect at HP
“So far, I heard about Service Oriented architecture all over. Everyone mentions it – the big buzz word. But, when I actually asked someone for what does it really mean, no one managed to give me a complete satisfied answer. Finally in his excellent course “Advanced Distributed Systems”, I got the answers I was looking for. Udi went over the different motivations (principles) of Services Oriented, explained them well one by one, and showed how each one could be technically addressed using NService bus. In his course, Udi also explain the way of thinking when coming to design a Service Oriented system. What are the questions you need to ask yourself in order to shape your system, place the logic in the right places for best Service Oriented system.

I would recommend this course for any architect or developer who deals with distributed system, but not only. In my work we do not have a real distributed system, but one PC which host both the UI application and the different services inside, all communicating via WCF. I found that many of the architecture principles and motivations of SOA apply for our system as well. Enough that you have SW partitioned into components and most of the principles becomes relevant to you as well. Bottom line – an excellent course recommended to any SW Architect, or any developer dealing with distributed system.”

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