|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
Many of the well-known examples of DevOps success we read in blogs on the Internet paint an idyllic picture of DevOps productivity. A team was facing a stodgy, slow-moving operations department, teams weren’t delivering software on time. Those teams moved to DevOps, became proactive about infrastructure and deployment automation, and an overnight transition to productivity ensues. People are promoted, projects are successful, and developers and system administrators dance hand-in-hand in a final...
Apr. 28, 2015 11:15 AM EDT Reads: 1,311
In 2015, 4.9 billion connected "things" will be in use. By 2020, Gartner forecasts this amount to be 25 billion, a 410 percent increase in just five years. How will businesses handle this rapid growth of data? Hadoop will continue to improve its technology to meet business demands, by enabling businesses to access/analyze data in real time, when and where they need it. Cloudera's Chief Technologist, Eli Collins, will discuss how Big Data is keeping up with today's data demands and how in t...
Apr. 28, 2015 11:00 AM EDT Reads: 1,525
SYS-CON Media announced today that @ThingsExpo Blog launched with 7,788 original stories. @ThingsExpo Blog 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. @ThingsExpo Blog can be bookmarked. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago.
Apr. 28, 2015 11:00 AM EDT Reads: 2,648
As Marc Andreessen says software is eating the world. Everything is rapidly moving toward being software-defined – from our phones and cars through our washing machines to the datacenter. However, there are larger challenges when implementing software defined on a larger scale - when building software defined infrastructure. In his session at 16th Cloud Expo, Boyan Ivanov, CEO of StorPool, will provide some practical insights on what, how and why when implementing "software-defined" in the dat...
Apr. 28, 2015 11:00 AM EDT Reads: 1,723
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
Apr. 28, 2015 11:00 AM EDT Reads: 2,143
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...
Apr. 28, 2015 11:00 AM EDT Reads: 3,668
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch ...
Apr. 28, 2015 11:00 AM EDT Reads: 2,956
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...
Apr. 28, 2015 11:00 AM EDT Reads: 2,169
SYS-CON Events announced today that Litmus Automation 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. Litmus Automation’s vision is to provide a solution for companies that are in a rush to embrace the disruptive Internet of Things technology and leverage it for real business challenges. Litmus Automation simplifies the complexity of connected devices applications with Loop, a secure and scalable clou...
Apr. 28, 2015 11:00 AM EDT Reads: 1,861
How do you securely enable access to your applications in AWS without exposing any attack surfaces? The answer is usually very complicated because application environments morph over time in response to growing requirements from your employee base, your partners and your customers. In his session at 16th Cloud Expo, Haseeb Budhani, CEO and Co-founder of Soha, will share five common approaches that DevOps teams follow to secure access to applications deployed in AWS, Azure, etc., and the frict...
Apr. 28, 2015 10:30 AM EDT Reads: 1,750
While DevOps most critically and famously fosters collaboration, communication, and integration through cultural change, culture is more of an output than an input. In order to actively drive cultural evolution, organizations must make substantial organizational and process changes, and adopt new technologies, to encourage a DevOps culture. Moderated by Andi Mann, panelists will discuss how to balance these three pillars of DevOps, where to focus attention (and resources), where organizations m...
Apr. 28, 2015 10:15 AM EDT Reads: 2,140
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...
Apr. 28, 2015 10:00 AM EDT Reads: 3,100
Internet of Things (IoT) will be a hybrid ecosystem of diverse devices and sensors collaborating with operational and enterprise systems to create the next big application. In their session at @ThingsExpo, Bramh Gupta, founder and CEO of robomq.io, and Fred Yatzeck, principal architect leading product development at robomq.io, will discuss how choosing the right middleware and integration strategy from the get-go will enable IoT solution developers to adapt and grow with the industry, while at...
Apr. 28, 2015 10:00 AM EDT Reads: 2,041
The only place to be June 9-11 is Cloud Expo & @ThingsExpo 2015 East at the Javits Center in New York City. Join us there as delegates from all over the world come to listen to and engage with speakers & sponsors from the leading Cloud Computing, IoT & Big Data companies. Cloud Expo & @ThingsExpo are the leading events covering the booming market of Cloud Computing, IoT & Big Data for the enterprise. Speakers from all over the world will be hand-picked for their ability to explore the economic...
Apr. 28, 2015 10:00 AM EDT Reads: 4,281
SYS-CON Events announced today that Column Technologies, a global technology solutions company, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Established in 1998, Column Technologies is a leader in application performance and infrastructure management for commercial and federal markets. The company is headquartered in the United States, with a diverse and talented team of more than 350 employees around th...
Apr. 28, 2015 10:00 AM EDT Reads: 1,851
Deploying and operating cloud technology is difficult and falls outside the core competencies of most organizations. As a result, many on-premises private cloud installations falter, casting doubt on private cloud as a solution in general. Yet private clouds come with a unique set of benefits that continue to drive widespread interest. There must be a better way. This session will give participants a clear roadmap of private cloud implementation challenges and offer actionable ideas for...
Apr. 28, 2015 10:00 AM EDT Reads: 1,293
Database apps on mobile devices shouldn't stop working when there's limited or no network connectivity. In his session at 16th Cloud Expo, Bradley Holt, a Developer Advocate for IBM Cloudant, will discuss how to bring data stored in a cloud database to the edge of the network (and back again), whenever an Internet connection is available. He will demonstrate techniques for replicating cloud databases with mobile devices in order to build offline-enabled mobile apps that can provide a better,...
Apr. 28, 2015 10:00 AM EDT Reads: 106
SYS-CON Events announced today that the DevOps Institute has been named “Association Sponsor” of SYS-CON's DevOps Summit, which will take place on June 9–11, 2015, at the Javits Center in New York City, NY. The DevOps Institute provides enterprise level training and certification. Working with thought leaders from the DevOps community, the IT Service Management field and the IT training market, the DevOps Institute is setting the standard in quality for DevOps education and training.
Apr. 28, 2015 10:00 AM EDT Reads: 2,244
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? Join this panel of experts as they peel away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud environment, and we must architect and code accordingly. At the very least, you’ll have no problem filling in your buzzword bingo cards.
Apr. 28, 2015 10:00 AM EDT Reads: 2,283
IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what th...
Apr. 28, 2015 10:00 AM EDT Reads: 6,274