|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.
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborat...
Mar. 28, 2015 07:00 PM EDT Reads: 5,146
Hosted PaaS providers have given independent developers and startups huge advantages in efficiency and reduced time-to-market over their more process-bound counterparts in enterprises. Software frameworks are now available that allow enterprise IT departments to provide these same advantages for developers in their own organization. In his workshop session at DevOps Summit, Troy Topnik, ActiveState’s Technical Product Manager, will show how on-prem or cloud-hosted Private PaaS can enable organ...
Mar. 28, 2015 05:45 PM EDT Reads: 1,039
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Thi...
Mar. 28, 2015 04:15 PM EDT Reads: 1,463
Cloud computing is changing the way we look at IT costs, according to industry experts on a recent Cloud Luminary Fireside Chat panel discussion. Enterprise IT, traditionally viewed as a cost center, now plays a central role in the delivery of software-driven goods and services. Therefore, companies need to understand their cloud utilization and resulting costs in order to ensure profitability on their business offerings. Led by Bernard Golden, this fireside chat offers valuable insights on ho...
Mar. 28, 2015 04:15 PM EDT Reads: 655
Exelon Corporation employs technology and process improvements to optimize their IT operations, manage a merger and acquisition transition, and to bring outsourced IT operations back in-house. To learn more about how this leading energy provider in the US, with a family of companies having $23.5 billion in annual revenue, accomplishes these goals we're joined by Jason Thomas, Manager of Service, Asset and Release Management at Exelon. The discussion is moderated by me, Dana Gardner, Principal A...
Mar. 28, 2015 03:15 PM EDT Reads: 689
SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional S...
Mar. 28, 2015 03:00 PM EDT Reads: 2,722
SYS-CON Events announced today that MangoApps will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY., and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. MangoApps provides private all-in-one social intranets allowing workers to securely collaborate from anywhere in the world and from any device. Social, mobile, and eas...
Mar. 28, 2015 03:00 PM EDT Reads: 2,984
Modern Systems announced completion of a successful project with its new Rapid Program Modernization (eavRPMa"c) software. The eavRPMa"c technology architecturally transforms legacy applications, enabling faster feature development and reducing time-to-market for critical software updates. Working with Modern Systems, the University of California at Santa Barbara (UCSB) leveraged eavRPMa"c to transform its Student Information System from Software AG's Natural syntax to a modern application lev...
Mar. 28, 2015 02:00 PM EDT Reads: 886
SYS-CON Events announced today Sematext Group, Inc., a Brooklyn-based Performance Monitoring and Log Management solution provider, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Sematext is a globally distributed organization that builds innovative Cloud and On Premises solutions for performance monitoring, alerting and anomaly detection (SPM), log management and analytics (Logsene), search analytics (S...
Mar. 28, 2015 01:00 PM EDT Reads: 3,347
In the midst of the widespread popularity and adoption of cloud computing, it seems like everything is being offered “as a Service” these days: Infrastructure? Check. Platform? You bet. Software? Absolutely. Toaster? It’s only a matter of time. With service providers positioning vastly differing offerings under a generic “cloud” umbrella, it’s all too easy to get confused about what’s actually being offered. In his session at 16th Cloud Expo, Kevin Hazard, Director of Digital Content for SoftL...
Mar. 28, 2015 01:00 PM EDT Reads: 1,358
When it comes to microservices there are myths and uncertainty about the journey ahead. Deploying a “Hello World” app on Docker is a long way from making microservices work in real enterprises with large applications, complex environments and existing organizational structures. February 19, 2015 10:00am PT / 1:00pm ET → 45 Minutes Join our four experts: Special host Gene Kim, Gary Gruver, Randy Shoup and XebiaLabs’ Andrew Phillips as they explore the realities of microservices in today’s IT worl...
Mar. 28, 2015 12:45 PM EDT Reads: 1,773
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on T...
Mar. 28, 2015 12:00 PM EDT Reads: 1,378
SYS-CON Media announced that IBM, which offers the world’s deepest portfolio of technologies and expertise that are transforming the future of work, has launched ad campaigns on SYS-CON’s numerous online magazines such as Cloud Computing Journal, Virtualization Journal, SOA World Magazine, and IoT Journal. IBM’s campaigns focus on vendors in the technology marketplace, the future of testing, Big Data and analytics, and mobile platforms.
Mar. 28, 2015 11:15 AM EDT Reads: 1,615
For those of us that have been practicing SOA for over a decade, it's surprising that there's so much interest in microservices. In fairness microservices don't look like the vendor play that was early SOA in the early noughties. But experienced SOA practitioners everywhere will be wondering if microservices is actually a good thing. You see microservices is basically an SOA pattern that inherits all the well-known SOA principles and adds characteristics that address the use of SOA for distribut...
Mar. 28, 2015 11:00 AM EDT Reads: 945
Microservice architectures are the new hotness, even though they aren't really all that different (in principle) from the paradigm described by SOA (which is dead, or not dead, depending on whom you ask). One of the things this decompositional approach to application architecture does is encourage developers and operations (some might even say DevOps) to re-evaluate scaling strategies. In particular, the notion is forwarded that an application should be built to scale and then infrastructure sho...
Mar. 28, 2015 11:00 AM EDT Reads: 2,384
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Ras...
Mar. 28, 2015 11:00 AM EDT Reads: 2,018
Microservices are the result of decomposing applications. That may sound a lot like SOA, but SOA was based on an object-oriented (noun) premise; that is, services were built around an object - like a customer - with all the necessary operations (functions) that go along with it. SOA was also founded on a variety of standards (most of them coming out of OASIS) like SOAP, WSDL, XML and UDDI. Microservices have no standards (at least none deriving from a standards body or organization) and can be b...
Mar. 28, 2015 10:45 AM EDT Reads: 2,080
Our guest on the podcast this week is Jason Bloomberg, President at Intellyx. When we build services we want them to be lightweight, stateless and scalable while doing one thing really well. In today's cloud world, we're revisiting what to takes to make a good service in the first place. Listen in to learn why following "the book" doesn't necessarily mean that you're solving key business problems.
Mar. 28, 2015 10:45 AM EDT Reads: 1,223
Right off the bat, Newman advises that we should "think of microservices as a specific approach for SOA in the same way that XP or Scrum are specific approaches for Agile Software development". These analogies are very interesting because my expectation was that microservices is a pattern. So I might infer that microservices is a set of process techniques as opposed to an architectural approach. Yet in the book, Newman clearly includes some elements of concept model and architecture as well as p...
Mar. 28, 2015 10:15 AM EDT Reads: 2,078
Microservices, for the uninitiated, are essentially the decomposition of applications into multiple services. This decomposition is often based on functional lines, with related functions being grouped together into a service. While this may sound a like SOA, it really isn't, especially given that SOA was an object-centered methodology that focused on creating services around "nouns" like customer and product. Microservices, while certainly capable of being noun-based, are just as likely to be v...
Mar. 28, 2015 10:00 AM EDT Reads: 1,783