|By Thomas Erl||
|August 16, 2008 02:15 PM EDT||
Each SOA design pattern provides a design solution in support of successfully applying service orientation and establishing a quality service-oriented architecture. Therefore, to better understand how and to what extent individual SOA design patterns can be applied, SOA as an architectural model itself needs to be broken down into the following types, each of which represent a common "scope of implementation":
- Service Architecture: The architecture of a single service
- Service Composition Architecture: The architecture of a set of services assembled into a service composition
- Service Inventory Architecture: The architecture that supports a collection of related services that are independently standardized and governed
- Service-Oriented Enterprise Architecture: The architecture of the enterprise to whatever extent it is service-oriented
In a typical enterprise, these architecture types are very much interrelated, yet each requires individual design attention and documentation.
About the Patterns
This article is roughly organized according to these architecture types and related patterns.
SOA design patterns collectively form a master pattern language that allows patterns to be applied in different combinations and sequences. There are also compound patterns that are comprised of multiple individual design patterns. (For example, the Enterprise Service Bus and orchestration both represent compound design patterns.)
SOA design patterns are not specific to any particular vendor platform or business industry; they are simply design techniques that help overcome common obstacles to achieving the strategic goals and benefits associated with SOA and service-oriented computing.
The remainder of this article highlights key design patterns while referencing a cross-section of others. Not all mentioned patterns are explained, but descriptions are freely available at the SOA patterns community site (www.soapatterns.org).
Patterns for Collections of Services
A service inventory represents a collection of independently standardized and governed services. As shown in Figure 1, the services you deliver for a given service inventory are standardized and designed according to service orientation so that they become intrinsically interoperable. This then allows you to draw from this pool of services to assemble and augment service compositions repeatedly.
Inventory Boundary Patterns
One of the biggest decisions a project team faces when starting an SOA initiative is determining the appropriate scope of a service inventory. The Enterprise Inventory and Domain Inventory design patterns help address this decision point by providing alternative approaches.
The goal of the Enterprise Inventory pattern is to establish an enterprise-wide service inventory. The end result of achieving this pattern is considered desirable because it enables you to build all of your services according to the same design conventions to ensure consistent and widespread inter-service compatibility. It further guarantees that all of the services will be owned and evolved by the same group or department, which is the ultimate in centralized governance.
Although ideal, this approach is often not realistic, especially for larger organizations. It can raise various issues, including time and budget constraints, cultural and political concerns, and order of magnitude considerations (especially in relation to the long-term growth and governance of the inventory). These issues can introduce risks and problems that outweigh the benefit potential of applying this pattern.
This is the reason the Domain Inventory pattern has become so popular. It advocates an approach whereby the enterprise is divided into segments (domains), each of which represents a meaningful cross-silo scope. Often, the boundary of a domain inventory architecture is aligned with a business domain (such as accounting or claims). Services delivered into this architectural boundary are subject to the same design standards and governance practices, allowing them to be evolved independently from neighboring domain inventories in the same enterprise.
Although the use of this pattern can introduce the need for cross-domain data model and protocol conversion (as per the Schema Transformation and Protocol Bridging patterns), there are additional patterns (such as Cross-Domain Utility Layer, Dual Protocols, and Inventory Endpoint) that help reduce this impact.
Inventory Structure Patterns
Regardless of its scope, within the boundary of a service inventory, certain design patterns are applied to ensure a consistent structure in support of service orientation. For example, Logic Centralization positions reusable services as the sole or primary contact points for the logic they represent. This is further supported by the Service Normalization pattern that fosters service autonomy by reducing the amount of functional overlap between individual service boundaries to establish more of a "normalized" inventory.
The Service Layers pattern (and related, specialized layer patterns) can be used to further organize a service inventory into a set of logical layers, each of which is based on a different classification of service.
Note: Just a reminder that all of these structural patterns are only applied within the boundary of an inventory architecture. This means that, if you are working within the confines of a domain inventory, these patterns will not be applied on an enterprise-wide basis.
To support and extend the structure of a service inventory architecture, various other design patterns can be applied. Some (like Canonical Schema and Canonical Transport Protocol) help standardize the services within the inventory boundary to foster native interoperability and composability, while others (like Process Centralization and Rules Centralization) can be selectively used to leverage established product platforms that support the centralized management of business process logic and business rules, respectively.
Yet another dimension to inventory architecture design is the centralization of service contract-related logic. The creation of redundant schema and policy content can be addressed by the Schema Centralization and Policy Centralization patterns, each of which establishes a separate data representation layer (one layer for data models, the other for global and domain-level policies) that supports the primary service contract layer.
There are many more specialized patterns that are applied to an inventory architecture to solve common problems related to resource management, state management, quality of service, security, and communication.
Patterns for Service Design
Each service exists as a standalone software program, autonomous yet still fully geared to participate in larger service aggregations. When designing a service architecture, numerous challenges can arise, especially when shaping this architecture according to service-orientation design principles, such as Service Statelessness and Service Loose Coupling. Figure 2 provides an abstract glimpse of service architecture design patterns that are applied at the service architecture level.
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, wh...
May. 25, 2016 02:30 PM EDT Reads: 1,858
IoT generates lots of temporal data. But how do you unlock its value? How do you coordinate the diverse moving parts that must come together when developing your IoT product? What are the key challenges addressed by Data as a Service? How does cloud computing underlie and connect the notions of Digital and DevOps What is the impact of the API economy? What is the business imperative for Cognitive Computing? Get all these questions and hundreds more like them answered at the 18th Cloud Expo...
May. 25, 2016 02:15 PM EDT Reads: 2,120
Cloud-based NCLC (No-code/low code) application builder platforms empower everyone in the organization to quickly build applications and executable processes that broaden access, deepen collaboration, and enhance transparency for all team members. Line of business owners (LOBO) and operations managers know best their part of the business and their processes. IT departments are beginning to leverage NCLC platforms to empower and enable LOBOs to lead the innovation, transform the organization, an...
May. 25, 2016 12:00 PM EDT Reads: 1,660
@DevOpsSummit taking place June 7-9, 2016 at Javits Center, New York City, and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
May. 25, 2016 11:00 AM EDT Reads: 3,288
SYS-CON Events announced today the Docker Meets Kubernetes – Intro into the Kubernetes World, being held June 9, 2016, in conjunction with 18th Cloud Expo | @ThingsExpo, at the Javits Center in New York, NY. Register for 'Docker Meets Kubernetes Workshop' Here! This workshop led by Sebastian Scheele, co-founder of Loodse, introduces participants to Kubernetes (container orchestration). Through a combination of instructor-led presentations, demonstrations, and hands-on labs, participants learn ...
May. 25, 2016 10:00 AM EDT Reads: 1,838
Just last week a senior Hybris consultant shared the story of a customer engagement on which he was working. This customer had problems, serious problems. We’re talking about response times far beyond the most liberal acceptable standard. They were unable to solve the issue in their eCommerce platform – specifically Hybris. Although the eCommerce project was delivered by a system integrator / implementation partner, the vendor still gets involved when things go really wrong. After all, the vendo...
May. 25, 2016 10:00 AM EDT Reads: 1,360
The initial debate is over: Any enterprise with a serious commitment to IT is migrating to the cloud. But things are not so simple. There is a complex mix of on-premises, colocated, and public-cloud deployments. In this power panel at 18th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists will look at the present state of cloud from the C-level view, and how great companies and rock star executives can use cloud computing to meet their most ambitious and disruptive business ...
May. 25, 2016 09:15 AM EDT Reads: 2,079
Agile teams report the lowest rate of measuring non-functional requirements. What does this mean for the evolution of quality in this era of Continuous Everything? To explore how the rise of SDLC acceleration trends such as Agile, DevOps, and Continuous Delivery are impacting software quality, Parasoft conducted a survey about measuring and monitoring non-functional requirements (NFRs). Here's a glimpse at what we discovered and what it means for the evolution of quality in this era of Continuo...
May. 25, 2016 07:15 AM EDT Reads: 1,442
You might already know them from theagileadmin.com, but let me introduce you to two of the leading minds in the Rugged DevOps movement: James Wickett and Ernest Mueller. Both James and Ernest are active leaders in the DevOps space, in addition to helping organize events such as DevOpsDays Austinand LASCON. Our conversation covered a lot of bases from the founding of Rugged DevOps to aligning organizational silos to lessons learned from W. Edwards Demings.
May. 25, 2016 07:00 AM EDT Reads: 1,343
When I talk about driving innovation with self-organizing teams, I emphasize that such self-organization includes expecting the participants to organize their own teams, give themselves their own goals, and determine for themselves how to measure their success. In contrast, the definition of skunkworks points out that members of such teams are “usually specially selected.” Good thing he added the word usually – because specially selecting such teams throws a wrench in the entire works, limiting...
May. 25, 2016 05:30 AM EDT Reads: 1,475
As AT&Ts VP of Domain 2.0 architecture writes one aspect of their Domain 2.0 strategy is a goal to embrace a Microservices Application Architecture. One page 9 they describe how these envisage them fitting into the ECOMP architecture: "The initial steps of the recipes include a homing and placement task using constraints specified in the requests. ‘Homing and Placement' are micro-services involving orchestration, inventory, and controllers responsible for infrastructure, network, and applicati...
May. 25, 2016 05:15 AM EDT Reads: 1,605
Application development and delivery methods have undergone radical changes in recent years to improve scalability and resiliency. Container images are the new build and deployment artifacts that are used to ship and run software. While startups have long been comfortable experimenting with and embracing new technologies, even large enterprises are now re-architecting their software systems so that they can benefit from container-enabled micro services architectures. With the launch of DC/OS, w...
May. 25, 2016 05:00 AM EDT Reads: 1,340
Many banks and financial institutions are experimenting with containers in development environments, but when will they move into production? Containers are seen as the key to achieving the ultimate in information technology flexibility and agility. Containers work on both public and private clouds, and make it easy to build and deploy applications. The challenge for regulated industries is the cost and complexity of container security compliance. VM security compliance is already challenging, ...
May. 25, 2016 05:00 AM EDT Reads: 1,040
Earlier this week, we hosted a Continuous Discussion (#c9d9) on Continuous Delivery (CD) automation and orchestration, featuring expert panelists Dondee Tan, Test Architect at Alaska Air, Taco Bakker, a LEAN Six Sigma black belt focusing on CD, and our own Sam Fell and Anders Wallgren. During this episode, we discussed the differences between CD automation and orchestration, their challenges with setting up CD pipelines and some of the common chokepoints, as well as some best practices and tips...
May. 25, 2016 04:15 AM EDT Reads: 1,271
SYS-CON Events announced today TechTarget has been named “Media 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. TechTarget is the Web’s leading destination for serious technology buyers researching and making enterprise technology decisions. Its extensive global networ...
May. 25, 2016 04:15 AM EDT Reads: 3,052
Korean Broadcasting System (KBS) will feature the upcoming 18th Cloud Expo | @ThingsExpo in a New York news documentary about the "New IT for the Future." The documentary will cover how big companies are transmitting or adopting the new IT for the future and will be filmed on the expo floor between June 7-June 9, 2016, at the Javits Center in New York City, New York. KBS has long been a leader in the development of the broadcasting culture of Korea. As the key public service broadcaster of Korea...
May. 25, 2016 04:00 AM EDT Reads: 1,718
Automation is a critical component of DevOps and Continuous Delivery. This morning on #c9d9 we discussed CD Automation and how you can apply Automation to accelerate release cycles, improve quality, safety and governance? What is the difference between Automation and Orchestration? Where should you begin your journey to introduce both?
May. 25, 2016 02:45 AM EDT Reads: 1,291
While there has been much ado about interoperability, there are still no real solutions, same as last year and the year before that. The large EHR vendors who continue to dominate the market still maintain that interoperability is all but solved, still can't connect EHRs across the continuum causing frustration by providers and a disservice to patients. The ONC pays lip service to the problem, but that is about it. It is time for the healthcare industry to consider alternatives like middleware w...
May. 24, 2016 09:45 PM EDT Reads: 1,497
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty ...
May. 24, 2016 06:00 PM EDT Reads: 4,684
Our CTO, Anders Wallgren, recently sat down to take part in the “B2B Nation: IT” podcast — the series dedicated to serving the IT professional community with expert opinions and advice on the world of information technology. Listen to the great conversation, where Anders shares his thoughts on DevOps lessons from large enterprises, the growth of microservices and containers, and more.
May. 24, 2016 05:00 PM EDT Reads: 1,464