Click here to close now.



Welcome!

Microservices Expo Authors: Jason Bloomberg, Elizabeth White, Pat Romanski, Liz McMillan, Anders Wallgren

Related Topics: Microservices Expo

Microservices Expo: Article

Exclusive SOA Web Services Journal Briefing – Thomas Erl On SOA

The Principles of Service-Orientation

With the unwavering prominence of service-oriented architecture (SOA) there is an increasing interest in understanding what exactly it means for something to be considered "service-oriented." Thomas Erl recently completed a lengthy research project for SOA Systems Inc. into the origins of SOA and the current state of service-orientation among all primary SOA technology platforms. This body of work contributed to the mainstream SOA methodology developed by SOA Systems and was also documented in Thomas's new book, Service-Oriented Architecture: Concepts, Technology, and Design. We caught up with Thomas (a previous contributor to WSJ) to ask him to share some of the insights he gained from his work with SOA and service-orientation.

There's no need to mention that SOA has become a major focal point of the IT industry and a primary consideration on numerous corporate agendas. Nor is there a need to get into how SOA has been so heavily promoted that the term has already reached hall-of-fame status as one of the most recognized acronyms in IT history.

What is more important than the term itself is the impact its perceived meaning continues to have on how automation solutions are constructed. Its popularity to date is largely the result of vendors advertising SOA support or capability as part of their product lines. Because SOA has been so vendor-driven, its meaning has been somewhat divergent, skewed by proprietary technology that is still identified with common characteristics that transcend proprietary boundaries.

These common characteristics are critical to defining and understanding an abstract technology architecture classified as "service-oriented." Viewing SOA in abstract is what establishes an agnostic reference point from which proprietary implementations can be measured and, ultimately, unified.

Vendor-Oriented Service-Orientation
Vendors and other organizations in the SOA space have published numerous papers, blueprints, and even frameworks. Most such documents serve the dual purpose of educating readers about SOA while marketing related products or services. This is nothing new. Past variations of client-server and distributed architecture models have varied significantly in both technology and design, depending mostly on who and what was used to implement them.

However, because a core expectation of SOA is its ability to harmonize and streamline diverse technical environments, preserving an abstract viewpoint is required to achieving its potential. This is because SOA, when elevated to an enterprise level, can be used to establish an ecosystem in which an agnostic, overarching framework transcends proprietary environments and constraints.

How the components and elements within this framework are shaped and standardized is of critical importance. This underlines the need for a design paradigm that is sufficiently generic so that it can be applied to solutions regardless of implementation, while remaining in alignment with where powerhouse vendors and organizations are currently taking the technology that is fueling the service-oriented computing platform.

Service-Orientation and Object-Orientation
Design paradigms have played an important role in the evolution of technology and application architecture. The most widely recognized paradigm for distributed business automation has been object-orientation. The system-wide implementation technology for object-oriented solutions has traditionally been proprietary, where, despite the use of the agnostic principles of object-orientation, objects or components are designed to function and interact by using technology and protocols specific to a computing and/or vendor platform.

Service-orientation owes much of its existence to object-orientation. Like traditional multitiered architectures, SOA is based on a model wherein solution logic is distributed. As with object-orientation, concepts such as encapsulation, abstraction, and reusability are fundamental to the design of distributed units of automation logic (services) within SOA. Key differences in these approaches are focused on how these units relate to each other and the scope at which the respective paradigms can be applied.

See Figure 1

Service-Orientation and the Separation of Concerns
I have yet to find a better means of explaining service-orientation than to reach back to that fundamental software engineering theory known as the "separation of concerns." This theory essentially proposes that larger problems be decomposed into a series of individually identifiable problems or "concerns." The logic required to address or solve the larger problem can then also be broken down into individual units of logic that address specific concerns.

Past design paradigms and development platforms have applied this theory in different ways. Component-based and object-oriented designs, for example, provide specific approaches for the decomposition of concerns and the design of corresponding solution logic. Service-orientation establishes a new and distinct means of realizing a separation of concerns. As a design paradigm, it is an evolution of past approaches, augmented and extended in support of the overall goals and characteristics of SOA.

See Figure 2

Common Service-Orientation Principles
Service-orientation began with a modest scope - a basic set of principles centered on an architectural model focused primarily on distinguishing services as reusable and discoverable resources. However, technology architecture in support of service-orientation is making significant strides, and extending its reach into key realms of enterprise computing.

Expectations are being raised surrounding a new era of business automation composed of services as adaptive, shared software assets that promise to infuse an enterprise with organization-level agility, federated interoperability, and vendor independence. These expectations have placed demands on what a distributed automation solution classified as "service-oriented" should be capable of, expanding the breadth of the service-oriented paradigm and adding to and further shaping its principles.

So far, eight common and fundamental principles have been identified. Note that these are classified as "common" in that they represent a cross-section of the most widely accepted design approaches and best practices promoted and practiced by the organizations most responsible for realizing the contemporary SOA movement.

Here then are the common principles of service-orientation:

  • services are loosely coupled
  • services share a formal contract
  • services abstract underlying logic
  • services are composable
  • services are reusable
  • services are autonomous
  • services are stateless
  • services are discoverable

More Stories By Thomas Erl

Thomas Erl is a best-selling IT author and founder of Arcitura Education Inc., a global provider of vendor-neutral educational services and certification that encompasses the Cloud Certified Professional (CCP) and SOA Certified Professional (SOACP) programs from CloudSchool.com™ and SOASchool.com® respectively. Thomas has been the world's top-selling service technology author for nearly a decade and is the series editor of the Prentice Hall Service Technology Series from Thomas Erl, as well as the editor of the Service Technology Magazine. With over 175,000 copies in print world-wide, his eight published books have become international bestsellers and have been formally endorsed by senior members of many major IT organizations and academic institutions. To learn more, visit: www.thomaserl.com

Comments (3) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
erl 10/29/05 06:17:48 AM EDT

{{{ have yet to find a better means of explaining service-orientation than to reach back to that fundamental software engineering theory known as the "separation of concerns." }}}

I'd not heard this one before. Useful phrase.

queZZtion 10/29/05 05:36:51 AM EDT

||| technology architecture in support of service-orientation is making significant strides, and extending its reach into key realms of enterprise computing |||

The age of SOA will last much longer than the age of client/server. How long though?

Short&Sweet 10/29/05 05:32:53 AM EDT

Erl's book on this subject, Service-Oriented Architecture: Concepts, Technology, and Design has 792 pages - helpful to have this boiled down to just 3 pages here!

@MicroservicesExpo Stories
The battle over bimodal IT is heating up. Now that there’s a reasonably broad consensus that Gartner’s advice about bimodal IT is deeply flawed – consensus everywhere except perhaps at Gartner – various ideas are springing up to fill the void. The bimodal problem, of course, is well understood. ‘Traditional’ or ‘slow’ IT uses hidebound, laborious processes that would only get in the way of ‘fast’ or ‘agile’ digital efforts. The result: incoherent IT strategies and shadow IT struggles that lead ...
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
SYS-CON Events announced today that VAI, a leading ERP software provider, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. VAI (Vormittag Associates, Inc.) is a leading independent mid-market ERP software developer renowned for its flexible solutions and ability to automate critical business functions for the distribution, manufacturing, specialty retail and service sectors. An IBM Premier Business Part...
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
In most cases, it is convenient to have some human interaction with a web (micro-)service, no matter how small it is. A traditional approach would be to create an HTTP interface, where user requests will be dispatched and HTML/CSS pages must be served. This approach is indeed very traditional for a web site, but not really convenient for a web service, which is not intended to be good looking, 24x7 up and running and UX-optimized. Instead, talking to a web service in a chat-bot mode would be muc...
SYS-CON Events announced today that Catchpoint Systems, Inc., a provider of innovative web and infrastructure monitoring solutions, has been named “Silver Sponsor” of SYS-CON's DevOps Summit at 18th Cloud Expo New York, which will take place June 7-9, 2016, at the Javits Center in New York City, NY. Catchpoint is a leading Digital Performance Analytics company that provides unparalleled insight into customer-critical services to help consistently deliver an amazing customer experience. Designed...
The (re?)emergence of Microservices was especially prominent in this week’s news. What are they good for? do they make sense for your application? should you take the plunge? and what do Microservices mean for your DevOps and Continuous Delivery efforts? Continue reading for more on Microservices, containers, DevOps culture, and more top news from the past week. As always, stay tuned to all the news coming from@ElectricCloud on DevOps and Continuous Delivery throughout the week and retweet/favo...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 ad...
More and more companies are looking to microservices as an architectural pattern for breaking apart applications into more manageable pieces so that agile teams can deliver new features quicker and more effectively. What this pattern has done more than anything to date is spark organizational transformations, setting the foundation for future application development. In practice, however, there are a number of considerations to make that go beyond simply “build, ship, and run,” which changes ho...
SYS-CON Events announced today that AppNeta, the leader in performance insight for business-critical web applications, will exhibit and present at SYS-CON's @DevOpsSummit at Cloud Expo New York, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. AppNeta is the only application performance monitoring (APM) company to provide solutions for all applications – applications you develop internally, business-critical SaaS applications you use and the networks that deli...
If we look at slow, traditional IT and jump to the conclusion that just because we found its issues intractable before, that necessarily means we will again, then it’s time for a rethink. As a matter of fact, the world of IT has changed over the last ten years or so. We’ve been experiencing unprecedented innovation across the board – innovation in technology as well as in how people organize and accomplish tasks. Let’s take a look at three differences between today’s modern, digital context...
As software organizations continue to invest in achieving Continuous Delivery (CD) of their applications, we see increased interest in microservices architectures, which–on the face of it–seem like a natural fit for enabling CD. In microservices (or its predecessor, “SOA”), the business functionality is decomposed into a set of independent, self-contained services that communicate with each other via an API. Each of the services has their own application release cycle, and are developed and depl...
At the heart of the Cloud Native model is a microservices application architecture, and applying this to a telco SDN scenario offers enormous opportunity for product innovation and competitive advantage. For example in the ETSI NFV Ecosystem white paper they describe one of the product markets that SDN might address to be the Home sector. Vendors like Alcatel market SDN-based solutions for the home market, offering Home Gateways – A virtual residential gateway (vRGW) where service provider...
In the Bimodal model we find two areas of IT - the traditional kind where the main concern is keeping the lights on and the IT focusing on agility and speed, where everything needs to be faster. Today companies are investing in new technologies and processes to emulate their most agile competitors. Gone are the days of waterfall development and releases only every few months. Today's IT and the business it powers demands performance akin to a supercar - everything needs to be faster, every sc...
With microservices, SOA and distributed architectures becoming more popular, it is becoming increasingly harder to keep track of where time is spent in a distributed application when trying to diagnose performance problems. Distributed tracing systems attempt to address this problem by following application requests across service boundaries, persisting metadata along the way that provide context for fine-grained performance monitoring.
Web performance issues and advances have been gaining a stronger presence in the headlines as people are becoming more aware of its impact on virtually every business, and 2015 was no exception. We saw a myriad of major outages this year hit some of the biggest corporations, as well as some technology integrations and other news that we IT Ops aficionados find very exciting. This past year has offered several opportunities for growth and evolution in the performance realm — even the worst failu...
Are you someone who knows that the number one rule in DevOps is “Don’t Panic”? Especially when it comes to making Continuous Delivery changes inside your organization? Are you someone that theorizes that if anyone implements real automation changes, the solution will instantly become antiquated and be replaced by something even more bizarre and inexplicable?
Welcome to the first top DevOps news roundup of 2016! At the end of last year, we saw some great predictions for 2016. While we’re excited to kick off the new year, this week’s top posts reminded us to take a second to slow down and really understand the current state of affairs. For example, do you actually know what microservices are – or aren’t? What about DevOps? Does the emphasis still fall mostly on the development side? This week’s top news definitely got the wheels turning and just migh...
Test automation is arguably the most important innovation to the process of QA testing in software development. The ability to automate regression testing and other repetitive test cases can significantly reduce the overall production time for even the most complex solutions. As software continues to be developed for new platforms – including mobile devices and the diverse array of endpoints that will be created during the rise of the Internet of Things - automation integration will have a huge ...
Providing a full-duplex communication channel over a single TCP connection, WebSocket is the most efficient protocol for real-time responses over the web. If you’re utilizing WebSocket technology, performance testing will boil down to simulating the bi-directional nature of your application. Introduced with HTML5, the WebSocket protocol allows for more interaction between a browser and website, facilitating real-time applications and live content. WebSocket technology creates a persistent conne...