Welcome!

Microservices Expo Authors: Yeshim Deniz, Pat Romanski, Todd Matters, Mark Leake, Stefana Muller

Related Topics: Microservices Expo

Microservices Expo: Article

SOA Pattern of the Week (#2): Non-Agnostic Context

Encapsulate single-purpose logic into services tuned and optimized to take part in service compositions

Should a service only be considered a service if it's reusable? The answer to this question, as asserted by this pattern, is a firm "no." While agnostic services (services providing multi-purpose logic with reuse potential, as per the Agnostic Context pattern), receive the most attention during service modeling and design phases, it can often be short-sighted to focus only on agnostic service logic.

Non-agnostic logic represents any type of functionality that is unique to a given business process or task. In other words, non-agnostic logic is single-purpose in nature and therefore has no reuse expectations. One of the most common forms of non-agnostic logic relates to the composition of other services.

When combining various services into a larger service composition, a parent layer of business decision-driven functions often emerges to establish the overarching workflow of the business task. Because this type of functionality is often task-specific, it is classified as single-purpose (or non-agnostic) and further grouped into a separate task service (a service model established by a related pattern called Process Abstraction).

It's clear that in most service-oriented solutions the non-agnostic logic needs to be separated from the agnostic logic, but why does it need to be located in services? The short answer is: "it doesn't." You can position this parent logic in a rich client, a monolithic system, or some other software program that is evidently not service-oriented, and the service composition can still be carried out. The Non-Agnostic Context pattern does not require that you create task services, it simply points out that there are benefits to doing so.

These benefits have recently been documented in detail in the article "The Case for Single-Purpose Services: Understanding the Non-Agnostic Context and a Strategy for Implementation" by author Herbjorn Wilhelmsen. We won't be repeating them all here, but let's at least list them:

  • Multiple Providers
  • Isolation Against Change
  • Centralizing Governance (Keeping it Together)
  • Service Composition Optimization
  • Offloading Work from Client Computers
  • Business Alignment (Separation of Concerns)

As an example, let's pick the fourth item on this list so that we can take a brief look at how this pattern can help optimize service compositions.

Service-orientation takes the notion of a composition to a whole new level. It is not just focused on the successful aggregation of distributed software programs into a self-contained application, it has its sights set on flexible and adaptive composition. This means that services need to be designed not only to participate in a larger composition, but to facilitate the continuous need to augment, extend, or re-configure existing compositions and to take part in new compositions, to whatever extent business change demands it.

The inherent ability to effectively recompose services (as per the Capability Recomposition pattern) lies at the heart of service-orientation in its quest to enable maximum business agility at an organizational level. Service-orientation design principles address this goal by shaping services into highly effective composition participants.

Another way to think of this is to view it from the composition's perspective. A service composition is a mechanical entity, comprised of distributed moving parts that need to work in concert at runtime in order to carry out the overarching business task. Any part of this composition not subjected to the rigor of service-orientation can become a weak link that can inhibit or even compromise the quality and performance of the composition as a whole.

Isolating non-agnostic logic into a non-service-oriented program or platform can therefore reduce the effectiveness and potential of service compositions, sometimes dramatically so. This is especially the case with larger, more complex compositions, where inter-service reliance on mutually elevated runtime behavioral requirements and performance demands is further magnified.

It is these requirements and demands that the Non-Agnostic Context pattern can address, so that single-purpose logic is encapsulated into services tuned and optimized to take part in service compositions as they exist today, while further facilitating their on-going and anticipated evolutionary changes.

•   •   •

The SOA Pattern of the Week series is comprised of original content and insights provided to you courtesy of the authors and contributors of the SOAPatterns.org community site and the book "SOA Design Patterns" (Erl et al., ISBN: 0136135161, Prentice Hall, 2009), the latest title in the "Prentice Hall Service-Oriented Computing Series from Thomas Erl" (www.soabooks.com). Copyright 2009 SOA Systems Inc.

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

More Stories By Herbjorn Wilhelmsen

Herbjorn Wilhelmsen is an Architect and Senior Consultant at Objectware in Stockholm, Sweden. His main focus areas include service-oriented architecture, Web services and business architecture. Herbjörn has many years of industry experience working as a developer, development manager, architect and teacher in several fields of operations, such as telecommunications, marketing, payment industry, health care and public services. He is active as an author in the Prentice Hall Service-Oriented Computing Series from Thomas Erl and has contributed design patterns to SOAPatterns.org. He leads the Business-to-IT group in the Swedish chapter of the International Association of Software Architects, which performs a comparative study of a number of business architecture methodologies. Herbjörn holds a Bachelor of Science from Stockholm University.

Comments (0)

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.


@MicroservicesExpo Stories
Cloud Expo, Inc. has announced today that Andi Mann and Aruna Ravichandran have been named Co-Chairs of @DevOpsSummit at Cloud Expo Silicon Valley which will take place Oct. 31-Nov. 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. "DevOps is at the intersection of technology and business-optimizing tools, organizations and processes to bring measurable improvements in productivity and profitability," said Aruna Ravichandran, vice president, DevOps product and solutions marketing...
"When we talk about cloud without compromise what we're talking about is that when people think about 'I need the flexibility of the cloud' - it's the ability to create applications and run them in a cloud environment that's far more flexible,” explained Matthew Finnie, CTO of Interoute, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
For most organizations, the move to hybrid cloud is now a question of when, not if. Fully 82% of enterprises plan to have a hybrid cloud strategy this year, according to Infoholic Research. The worldwide hybrid cloud computing market is expected to grow about 34% annually over the next five years, reaching $241.13 billion by 2022. Companies are embracing hybrid cloud because of the many advantages it offers compared to relying on a single provider for all of their cloud needs. Hybrid offers bala...
A common misconception about the cloud is that one size fits all. Companies expecting to run all of their operations using one cloud solution or service must realize that doing so is akin to forcing the totality of their business functionality into a straightjacket. Unlocking the full potential of the cloud means embracing the multi-cloud future where businesses use their own cloud, and/or clouds from different vendors, to support separate functions or product groups. There is no single cloud so...
Containers, microservices and DevOps are all the rage lately. You can read about how great they are and how they’ll change your life and the industry everywhere. So naturally when we started a new company and were deciding how to architect our app, we went with microservices, containers and DevOps. About now you’re expecting a story of how everything went so smoothly, we’re now pushing out code ten times a day, but the reality is quite different.
"We are a monitoring company. We work with Salesforce, BBC, and quite a few other big logos. We basically provide monitoring for them, structure for their cloud services and we fit into the DevOps world" explained David Gildeh, Co-founder and CEO of Outlyer, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
21st International Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Me...
If you cannot explicitly articulate how investing in a new technology, changing the approach or re-engineering the business process will help you achieve your customer-centric vision of the future in direct and measurable ways, you probably shouldn’t be doing it. At Intellyx, we spend a lot of time talking to technology vendors. In our conversations, we explore emerging new technologies that are either disrupting the way enterprise organizations work or that help enable those organizations to ...
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, Doug Vanderweide, an instructor at Linux Academy, discussed why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers wit...
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities. In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, posited that disruption is inevitable for comp...
For organizations that have amassed large sums of software complexity, taking a microservices approach is the first step toward DevOps and continuous improvement / development. Integrating system-level analysis with microservices makes it easier to change and add functionality to applications at any time without the increase of risk. Before you start big transformation projects or a cloud migration, make sure these changes won’t take down your entire organization.
There's a lot to gain from cloud computing, but success requires a thoughtful and enterprise focused approach. Cloud computing decouples data and information from the infrastructure on which it lies. A process that is a LOT more involved than dragging some folders from your desktop to a shared drive. Cloud computing as a mission transformation activity, not a technological one. As an organization moves from local information hosting to the cloud, one of the most important challenges is addressi...
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...
Companies have always been concerned that traditional enterprise software is slow and complex to install, often disrupting critical and time-sensitive operations during roll-out. With the growing need to integrate new digital technologies into the enterprise to transform business processes, this concern has become even more pressing. A 2016 Panorama Consulting Solutions study revealed that enterprise resource planning (ERP) projects took an average of 21 months to install, with 57 percent of t...
Microservices are increasingly used in the development world as developers work to create larger, more complex applications that are better developed and managed as a combination of smaller services that work cohesively together for larger, application-wide functionality. Tools such as Service Fabric are rising to meet the need to think about and build apps using a piece-by-piece methodology that is, frankly, less mind-boggling than considering the whole of the application at once. Today, we'll ...
In his session at Cloud Expo, Alan Winters, an entertainment executive/TV producer turned serial entrepreneur, presented a success story of an entrepreneur who has both suffered through and benefited from offshore development across multiple businesses: The smart choice, or how to select the right offshore development partner Warning signs, or how to minimize chances of making the wrong choice Collaboration, or how to establish the most effective work processes Budget control, or how to ma...
Hybrid IT is today’s reality, and while its implementation may seem daunting at times, more and more organizations are migrating to the cloud. In fact, according to SolarWinds 2017 IT Trends Index: Portrait of a Hybrid IT Organization 95 percent of organizations have migrated crucial applications to the cloud in the past year. As such, it’s in every IT professional’s best interest to know what to expect.
Both SaaS vendors and SaaS buyers are going “all-in” to hyperscale IaaS platforms such as AWS, which is disrupting the SaaS value proposition. Why should the enterprise SaaS consumer pay for the SaaS service if their data is resident in adjacent AWS S3 buckets? If both SaaS sellers and buyers are using the same cloud tools, automation and pay-per-transaction model offered by IaaS platforms, then why not host the “shrink-wrapped” software in the customers’ cloud? Further, serverless computing, cl...
In the decade following his article, cloud computing further cemented Carr’s perspective. Compute, storage, and network resources have become simple utilities, available at the proverbial turn of the faucet. The value they provide is immense, but the cloud playing field is amazingly level. Carr’s quote above presaged the cloud to a T. Today, however, we’re in the digital era. Mark Andreesen’s ‘software is eating the world’ prognostication is coming to pass, as enterprises realize they must be...
Colocation is a central pillar of modern enterprise infrastructure planning because it provides greater control, insight, and performance than managed platforms. In spite of the inexorable rise of the cloud, most businesses with extensive IT hardware requirements choose to host their infrastructure in colocation data centers. According to a recent IDC survey, more than half of the businesses questioned use colocation services, and the number is even higher among established businesses and busin...