|By Jason Bloomberg||
|May 30, 2014 01:00 PM EDT||
A question we commonly get at EnterpriseWeb is whether our platform follows REST or not. Representational State Transfer (REST) is an architectural style for distributed hypermedia systems such as the World Wide Web, and is perhaps best known for providing a lightweight, uniform Web-style application programming interface (API) to server-based resources. One the one hand, EnterpriseWeb can both consume and expose any type of interface, including tightly coupled APIs, Web Services, as well as RESTful APIs, and the platform has no requirement that customers must build distributed hypermedia systems. It would be easy to conclude, therefore, that while EnterpriseWeb supports REST, it is not truly RESTful.
Such a conclusion, however, would neglect the broader architectural context for EnterpriseWeb. The platform builds on top of and extends REST as the foundation for the dynamic, enterprise-class architectural style we call Agent-Oriented Architecture (AOA). EnterpriseWeb's intelligent agent, SmartAlex, leverages RESTful constraints as part of the core functionality of the EnterpriseWeb platform. The resulting AOA pattern essentially reinvents application functionality and enterprise integration, heralding a new paradigm for distributed computing.
The Limitations of REST
One of the primary challenges to the successful application of REST is understanding how to extend REST to distributed hypermedia systems in general, beyond the straightforward interactions between browsers and Web servers. To help clarify this point, Figure 1 below illustrates a simple RESTful architecture. In this example, the client is a browser, and it sends GETs and PUTs or other RESTful queries to URIs that resolve to resources on a server, which responds by sending the appropriate representation back to the client. In addition, REST allows for a cache intermediating between client and server that might resolve queries on behalf of the server for scalability purposes.
Figure 1: Simple RESTful Architecture
As an architectural style, however, the point of REST isn't the uniform interface that the HTTP verbs enable. REST is really about hypermedia, where hypermedia are the engine of application state - the HATEOAS constraint essential to building hypermedia systems. In figure 1, we're representing HATEOAS by the interactions between human users and their browsers as people click links on Web pages, thus advancing the application state. The RESTful client (in other words, the browser) maintains application state for each user by showing them the Web page (or other representation) they requested when they followed a given hyperlink.
However, software clients that do not necessarily have user interfaces may be problematic for REST, but they are a familiar part of the Service-Oriented Architecture (SOA) architectural style, where we call such clients Service consumers. Combining REST and SOA into the combined architectural style we call REST-Based SOA introduces the notion of an intermediary that presents a Service endpoint and resolves interactions with that endpoint into underlying interactions with various legacy systems. The SOA intermediary in this case exposes RESTful endpoints as URIs that accept GETs, PUTs, etc. from Service consumers, which can be any software client. See figure 2 below for an illustration of the REST-Based SOA pattern.
Figure 2: REST-Based SOA
Note that adding SOA to REST augments the role of the intermediary. Pure REST allows for simple caching and proxy behavior, while SOA calls for policy-based routing and transformation operations that provide the Service abstraction. SOA also reinforces the notion that the Service consumer can be any piece of software, regardless of whether it has a user interface.
Even with REST-based SOA, however, we still have problems with implementing HATEOAS: coding our clients so that they are able to gather the metadata they need by following hyperlinks. In other words, how do we apply REST to any hypermedia system, where instead of a browser we have any piece of software as a client? How do we code the software client to know how to follow hyperlinks, where it doesn't know what the hyperlinks are ahead of time or what representations they're supposed to interact with? Humans simply click hyperlinks until they get the representation they want, even if they don't know beforehand how to find it. How do we teach software to automate this process and gather all the metadata it needs by following a sequence of hyperlinks?
Introducing Agent-Oriented Architecture
The answer to these questions is to cast an intelligent agent in the role of SOA intermediary in the REST-Based SOA pattern in Figure 2. Intelligent software agents (or simply intelligent agents when we know we're talking about software) are autonomous programs that have the authority to determine what action is appropriate based upon the requests made of them. In this new, Agent-Oriented architectural pattern, the agent interacts with any resource as a RESTful client, where the agent must be able to automatically follow hyperlinks to gather all the information it requires in order to respond appropriately to any request from the client.
In other words, when following this newly coined AOA architectural style, software clients do not have to comply with HATEOAS (they may, but such compliance is optional). Instead, the agent alone must follow the HATEOAS constraint as it interacts with resources. To achieve this behavior, we must underspecify the intelligent agent. In other words, the agent can't know ahead of time what it's supposed to do to respond to any particular request. Instead, it must be able to process any request on demand by fetching related resources that provide the appropriate metadata, data, or code it needs to properly respond to that request with a custom response, for each interaction in real time. Figure 3 below illustrates the basic AOA pattern.
Figure 3: Agent-Oriented Architecture
For each request from any client, regardless of whether it has a user interface, the agent constructs a custom response based on latest and most relevant information available. In fact, requests to the agent can come from anywhere (i.e., they follow an event-driven pattern). The agent's underspecification means that it doesn't know ahead of time what behavior it must exhibit, but it does know how to find the information it needs in order to determine that behavior - and it does that by following hyperlinks, as per HATEOAS. In other words, the goal-oriented agent resolves URIs recursively in order to gather and execute the information it needs - a particularly concise example of fully automated HATEOAS in action.
The Benefits of AOA
An earlier Loosely-Coupled newsletter explained that if you follow REST, you're unable to accept out-of-band metadata or business context outside of the hypermedia. Agent-Oriented Architecture, however, solves these problems, because the agent is free to fetch whatever it needs to complete the request, since it treats all entities - metadata, data, code, etc. - as resources. In other words, the agent serves as a RESTful client, even when the software client does not. What was out-of-band for REST isn't out-of-band for AOA. Everything is on the table.
The true power of AOA, though, lies in how it resolves the fundamental challenge of static APIs. Whether they be Web Services, RESTful APIs, or some other type of loosely-coupled interface, every approach to software integration today suffers from the fact that interactions tend to break when API contract metadata change.
By adding an intelligent agent to the mix, we're able to resolve differences in interaction context between disparate software endpoints dynamically and in real time. Far more than a traditional broker, which must rely on static transformation logic to resolve endpoint differences, the agent must be able to interpret metadata, as well as policies, rules, and the underlying data themselves to create real time interactions that maintain the business context - an example of dynamic coupling, a central principle to AOA.
Dynamic coupling, therefore, represents a paradigm shift in how to build and utilize APIs. Up to this point in time, the focus of both SOA and REST has been on building loosely-coupled interfaces: static, contracted interfaces specified by WSDL and various policy metadata when those interfaces are Web Services, or Internet Media Types and related metadata for RESTful interactions. Neither approach deals well with change. AOA, in contrast, relies upon dynamic coupling that responds automatically to change, since the agent interprets current metadata for every interaction in real time.
Icons by http://dryicons.com
15th Cloud Expo, which took place Nov. 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA, expanded the conference content of @ThingsExpo, Big Data Expo, and DevOps Summit to include two developer events. IBM held a Bluemix Developer Playground on November 5 and ElasticBox held a Hackathon on November 6. Both events took place on the expo floor. The Bluemix Developer Playground, for developers of all levels, highlighted the ease of use of Bluemix, its services and functionalit...
Nov. 27, 2014 07:00 PM EST Reads: 1,731
"We help companies that are using a lot of Software as a Service. We help companies manage and gain visibility into what people are using inside the company and decide to secure them or use standards to lock down or to embrace the adoption of SaaS inside the company," explained Scott Kriz, Co-founder and CEO of Bitium, in this SYS-CON.tv interview at 15th Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Nov. 27, 2014 07:00 PM EST Reads: 1,751
Some developers believe that monitoring is a function of the operations team. Some operations teams firmly believe that monitoring the systems they maintain is sufficient to run the business successfully. Most of them are wrong. The complexity of today's applications have gone far and beyond the capabilities of "traditional" system-level monitoring tools and approaches and requires much broader knowledge of business and applications as a whole. The goal of DevOps is to connect all aspects of app...
Nov. 27, 2014 06:00 PM EST Reads: 1,477
The 4th International DevOps Summit, co-located with16th International Cloud Expo – being held June 9-11, 2015, at the Javits Center in New York City, NY – announces that its Call for Papers is now open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's large...
Nov. 27, 2014 06:00 PM EST Reads: 2,249
SAP is delivering break-through innovation combined with fantastic user experience powered by the market-leading in-memory technology, SAP HANA. In his General Session at 15th Cloud Expo, Thorsten Leiduck, VP ISVs & Digital Commerce, SAP, discussed how SAP and partners provide cloud and hybrid cloud solutions as well as real-time Big Data offerings that help companies of all sizes and industries run better. SAP launched an application challenge to award the most innovative SAP HANA and SAP HANA...
Nov. 27, 2014 05:00 PM EST Reads: 1,621
Want to enable self-service provisioning of application environments in minutes that mirror production? Can you automatically provide rich data with code-level detail back to the developers when issues occur in production? In his session at DevOps Summit, David Tesar, Microsoft Technical Evangelist on Microsoft Azure and DevOps, will discuss how to accomplish this and more utilizing technologies such as Microsoft Azure, Visual Studio online, and Application Insights in this demo-heavy session.
Nov. 27, 2014 04:45 PM EST Reads: 1,591
When an enterprise builds a hybrid IaaS cloud connecting its data center to one or more public clouds, security is often a major topic along with the other challenges involved. Security is closely intertwined with the networking choices made for the hybrid cloud. Traditional networking approaches for building a hybrid cloud try to kludge together the enterprise infrastructure with the public cloud. Consequently this approach requires risky, deep "surgery" including changes to firewalls, subnets...
Nov. 27, 2014 04:45 PM EST Reads: 1,815
DevOps is all about agility. However, you don't want to be on a high-speed bus to nowhere. The right DevOps approach controls velocity with a tight feedback loop that not only consists of operational data but also incorporates business context. With a business context in the decision making, the right business priorities are incorporated, which results in a higher value creation. In his session at DevOps Summit, Todd Rader, Solutions Architect at AppDynamics, discussed key monitoring techniques...
Nov. 27, 2014 04:30 PM EST Reads: 1,725
Cultural, regulatory, environmental, political and economic (CREPE) conditions over the past decade are creating cross-industry solution spaces that require processes and technologies from both the Internet of Things (IoT), and Data Management and Analytics (DMA). These solution spaces are evolving into Sensor Analytics Ecosystems (SAE) that represent significant new opportunities for organizations of all types. Public Utilities throughout the world, providing electricity, natural gas and water,...
Nov. 27, 2014 04:00 PM EST Reads: 1,830
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, a...
Nov. 27, 2014 04:00 PM EST Reads: 1,984
How do APIs and IoT relate? The answer is not as simple as merely adding an API on top of a dumb device, but rather about understanding the architectural patterns for implementing an IoT fabric. There are typically two or three trends: Exposing the device to a management framework Exposing that management framework to a business centric logic Exposing that business layer and data to end users. This last trend is the IoT stack, which involves a new shift in the separation of what stuff happe...
Nov. 27, 2014 03:00 PM EST Reads: 1,953
The 3rd International Internet of @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
Nov. 27, 2014 03:00 PM EST Reads: 1,382
The Internet of Things is tied together with a thin strand that is known as time. Coincidentally, at the core of nearly all data analytics is a timestamp. When working with time series data there are a few core principles that everyone should consider, especially across datasets where time is the common boundary. In his session at Internet of @ThingsExpo, Jim Scott, Director of Enterprise Strategy & Architecture at MapR Technologies, discussed single-value, geo-spatial, and log time series dat...
Nov. 27, 2014 03:00 PM EST Reads: 2,147
An entirely new security model is needed for the Internet of Things, or is it? Can we save some old and tested controls for this new and different environment? In his session at @ThingsExpo, New York's at the Javits Center, Davi Ottenheimer, EMC Senior Director of Trust, reviewed hands-on lessons with IoT devices and reveal a new risk balance you might not expect. Davi Ottenheimer, EMC Senior Director of Trust, has more than nineteen years' experience managing global security operations and asse...
Nov. 27, 2014 01:00 PM EST Reads: 2,048
The Internet of Things will greatly expand the opportunities for data collection and new business models driven off of that data. In her session at @ThingsExpo, Esmeralda Swartz, CMO of MetraTech, discussed how for this to be effective you not only need to have infrastructure and operational models capable of utilizing this new phenomenon, but increasingly service providers will need to convince a skeptical public to participate. Get ready to show them the money!
Nov. 27, 2014 11:00 AM EST Reads: 1,852
SYS-CON Media announced that Centrify, a provider of unified identity management across cloud, mobile and data center environments that delivers single sign-on (SSO) for users and a simplified identity infrastructure for IT, has launched an ad campaign on Cloud Computing Journal. The ads focus on security: how an organization can successfully control privilege for all of the organization’s identities to mitigate identity-related risk without slowing down the business, and how Centrify provides ...
Nov. 27, 2014 10:00 AM EST Reads: 1,741
The Internet of Things will put IT to its ultimate test by creating infinite new opportunities to digitize products and services, generate and analyze new data to improve customer satisfaction, and discover new ways to gain a competitive advantage across nearly every industry. In order to help corporate business units to capitalize on the rapidly evolving IoT opportunities, IT must stand up to a new set of challenges. In his session at @ThingsExpo, Jeff Kaplan, Managing Director of THINKstrateg...
Nov. 27, 2014 10:00 AM EST Reads: 1,877
"SAP had made a big transition into the cloud as we believe it has significant value for our customers, drives innovation and is easy to consume. When you look at the SAP portfolio, SAP HANA is the underlying platform and it powers all of our platforms and all of our analytics," explained Thorsten Leiduck, VP ISVs & Digital Commerce at SAP, in this SYS-CON.tv interview at 15th Cloud Expo, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Nov. 27, 2014 08:15 AM EST Reads: 1,608
One of the biggest challenges when developing connected devices is identifying user value and delivering it through successful user experiences. In his session at Internet of @ThingsExpo, Mike Kuniavsky, Principal Scientist, Innovation Services at PARC, described an IoT-specific approach to user experience design that combines approaches from interaction design, industrial design and service design to create experiences that go beyond simple connected gadgets to create lasting, multi-device exp...
Nov. 27, 2014 08:00 AM EST Reads: 1,818
Enthusiasm for the Internet of Things has reached an all-time high. In 2013 alone, venture capitalists spent more than $1 billion dollars investing in the IoT space. With "smart" appliances and devices, IoT covers wearable smart devices, cloud services to hardware companies. Nest, a Google company, detects temperatures inside homes and automatically adjusts it by tracking its user's habit. These technologies are quickly developing and with it come challenges such as bridging infrastructure gaps,...
Nov. 27, 2014 07:45 AM EST Reads: 1,985