Click here to close now.

Welcome!

Web 2.0 Authors: Elizabeth White, XebiaLabs Blog, Liz McMillan, Plutora Blog, Mike Kavis

Related Topics: Cloud Expo, Java, SOA & WOA, Security, Big Data Journal, SDN Journal

Cloud Expo: Article

Bringing Intelligence to REST

The API Economy has nearly run its course.

Whether you're a Cloud Computing aficionado, an enterprise integration specialist, or an IT executive, it's hard to have a conversation today without mention of REST. Representational State Transfer, or REST to the cognoscenti, is an architectural style that treats distributed computing problems as though they were Web problems. On the Web you have browsers chatting via HTTP to Web servers, and those servers can work whatever magic they need to in order to serve up the full wealth we've all come to expect from the World Wide Web. Take those basic Web patterns, extend them to general distributed computing problems (including Cloud and legacy integration), and voila! You have REST.

However, while REST has achieved substantial success in simplifying software interfaces and thus facilitating many forms of integration, it is still inherently inflexible. What works well for humans using browsers often doesn't apply to arbitrary software clients. And most fundamentally, REST does not address the most difficult distributed computing challenge of all: how to deal with dynamic business context.

Freeing Ourselves from REST's Four Constraints
The majority of RESTafarians, as the aforementioned cognoscenti have so eloquently dubbed themselves, treat REST as an Application Programming Interface (API) style. After all, REST does call for a uniform interface, a requirement that in one fell swoop addresses many of the knottier problems of Web Services and other, more tightly coupled API styles that came before. Compared to the complexities of Web Service operations or object-oriented remote method calls, REST's uniform interface is the essence of simplicity. Furthermore, there's no question that REST's uniform interface requirement is at the heart of what analysts like to refer to as the API Economy.

But there is more to REST than a uniform interface. In fact, REST isn't an API style at all. It's an architectural style. As an architectural style, REST consists of a set of constraints on software architecture. In other words, feel free to follow what architectural rules you like, but if you want to follow REST you must comply with the following RESTful constraints:

  1. Separation of resources from representations
  2. Manipulation of resources by representations
  3. Self-descriptive messages
  4. Hypermedia as the engine of application state, or HATEOAS

Let's take a quick tour of these constraints to put them in plain language. In so doing, we'll also why REST fails to adequately address the problem of dynamic business context.

The first constraint is essentially the encapsulation requirement. Resources are abstractions of capabilities on a server, while the representations are what the resources provide to the client. For example, a resource might be a php script running on a Web server, and the representation might be an HTML file it returns when a browser makes a GET request of it. But the browser never, ever gets the php itself; it only sees the HTML. The php is forever hidden from view.

The second constraint calls for the uniform interface. The only way that clients are able to interact with resources is by following hyperlinks in representations - in other words, making GET, POST, PUT, or DELETE requests to the URI of the resource, assuming we're using HTTP as our transport protocol, which we usually are.

The third, self-descriptive message constraint is actually quite straightforward: all the data as well as all the metadata the resource needs to process a request must be contained in that request, and correspondingly, the resource must send all necessary metadata in the representation response to the client that the client will need to understand the representation. In other words, REST requires that there be no out-of-band metadata: information pertinent to the interaction that doesn't actually appear in the interaction. Furthermore, the interaction must be stateless: the resource isn't expected to keep track of any information pertinent to any particular client.

The problem with this third constraint, of course, is that out-of-band metadata is very handy in many situations. Take security-related metadata, for example. REST calls for all such metadata to be in every request, which led to the development of the OAuth (Open Authorization) standard. Yes, OAuth is quite powerful and Web friendly. Yes, OAuth is making inroads into the enterprise. But do you really want to restrict the security protocols for all of your interactions to OAuth and nothing but OAuth? Probably not.

If you have a more complex interaction than a simple request, then the ban on out-of-band metadata becomes increasingly impractical. For example, let's say you're trying to support a complex business process by building a composite application. You're trying to follow REST so you're composing resources. But then you find you need to somehow deal with a range of policies, business rules, or other out-of-band metadata that impact the behavior of your composite application for certain users but not others. REST alone simply doesn't deal well with such complexities.

And then there's the fourth constraint: the dreaded HATEOAS. REST separates state information into two types: resource state and application state. Resource state is shared or persisted state information on the server, while application state is specific to the individual client, who negotiates the application (think abstracted Web site) by following hyperlinks. The HATEOAS constraint hammers home the fact that the point of REST is building distributed hypermedia systems, where the client is responsible for running hypermedia-based applications. In other words, the hypermedia contain the business context for the interactions between client and server.

Hypermedia drive the Web, of course, but once you start breaking down REST's notions of client and server, however, then the power of hypermedia starts to wane. After all, enterprises often want to build or leverage business applications that offer more than a simple Web site, especially when there's a shared business context across nodes, where those nodes are more than just clients and servers. Hypermedia - and REST - simply weren't built for such complex, dynamic situations.

The Devil in the Details
There's a very good reason why REST eschews out-of-band metadata and shared business context beyond the scope of hypermedia: both of these requirements are inherently dynamic, and furthermore, depend upon multiple actors - actors who may change over time. By constraining the architecture to avoid such complexities, REST provides a useful set of simplifications that have provided unquestionable value throughout the API economy.

The challenges in the section above, however, go well beyond REST. The problems we're discussing have plagued software interfaces in general, from the earliest screen-scraping programs to object-oriented APIs to Web Services to today's RESTful APIs. The entire notion of a software interface is an agreement between the people building the software provider and consumer endpoints that the interface behaves a particular way. Loose coupling, after all, relies upon an interface contract that fixes the behavior of the API so that the parties involved can make various decisions about their software under the covers without breaking the interaction. But woe to those who dare to change the contract, or who want to consider metadata the contract knows nothing about!

Out-of-band metadata and business context outside hypermedia applications are by definition exterior to the contract, and thus aren't amenable to any distributed computing architectural style that relies too heavily on static APIs. Therein lies the essential challenge of the API. To those analysts trumpeting the API Economy I say: the API Economy has nearly run its course. We've solved as many problems as we're going to solve with contracted software interfaces. But the business stakeholders still aren't happy. After all, it's their context - the business context - that APIs (whether RESTful or not) are so woefully unable to deal with. It's time for another approach.

The EnterpriseWeb Take
I'm not saying that we don't need APIs, of course, or that REST doesn't serve a useful purpose. I am declaring, however, that something critically important is missing from this picture. APIs are far too static to address issues of dynamic business context. We tried to address these issues with the SOA intermediary (typically an ESB), where the intermediary executed policy-based routing and transformation rules to abstract a set of inflexible Service interfaces, thus providing the illusion of flexibility, much as a flip deck provides the illusion of motion. But even the most successful implementers of SOA were still unable to deal with most out-of-band metadata - and dynamic business context? That nut no one has been able to crack.

What we really need is an entirely different kind of intermediary. A smarter intermediary that knows how to deal with all types of metadata and furthermore, can resolve the more difficult challenge of business context - in real time, where the business lives. In the next issue of Loosely-Coupled I'll discuss how such a smarter intermediary might actually work. And naturally, if you want to see one in action, drop us a line.

Image credit: lin440315

More Stories By Jason Bloomberg

Jason Bloomberg is the leading expert on architecting agility for the enterprise. As president of Intellyx, Mr. Bloomberg brings his years of thought leadership in the areas of Cloud Computing, Enterprise Architecture, and Service-Oriented Architecture to a global clientele of business executives, architects, software vendors, and Cloud service providers looking to achieve technology-enabled business agility across their organizations and for their customers. His latest book, The Agile Architecture Revolution (John Wiley & Sons, 2013), sets the stage for Mr. Bloomberg’s groundbreaking Agile Architecture vision.

Mr. Bloomberg is perhaps best known for his twelve years at ZapThink, where he created and delivered the Licensed ZapThink Architect (LZA) SOA course and associated credential, certifying over 1,700 professionals worldwide. He is one of the original Managing Partners of ZapThink LLC, the leading SOA advisory and analysis firm, which was acquired by Dovel Technologies in 2011. He now runs the successor to the LZA program, the Bloomberg Agile Architecture Course, around the world.

Mr. Bloomberg is a frequent conference speaker and prolific writer. He has published over 500 articles, spoken at over 300 conferences, Webinars, and other events, and has been quoted in the press over 1,400 times as the leading expert on agile approaches to architecture in the enterprise.

Mr. Bloomberg’s previous book, Service Orient or Be Doomed! How Service Orientation Will Change Your Business (John Wiley & Sons, 2006, coauthored with Ron Schmelzer), is recognized as the leading business book on Service Orientation. He also co-authored the books XML and Web Services Unleashed (SAMS Publishing, 2002), and Web Page Scripting Techniques (Hayden Books, 1996).

Prior to ZapThink, Mr. Bloomberg built a diverse background in eBusiness technology management and industry analysis, including serving as a senior analyst in IDC’s eBusiness Advisory group, as well as holding eBusiness management positions at USWeb/CKS (later marchFIRST) and WaveBend Solutions (now Hitachi Consulting).

@ThingsExpo Stories
PubNub on Monday has announced that it is partnering with IBM to bring its sophisticated real-time data streaming and messaging capabilities to Bluemix, IBM’s cloud development platform. “Today’s app and connected devices require an always-on connection, but building a secure, scalable solution from the ground up is time consuming, resource intensive, and error-prone,” said Todd Greene, CEO of PubNub. “PubNub enables web, mobile and IoT developers building apps on IBM Bluemix to quickly add scalable realtime functionality with minimal effort and cost.”
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
With several hundred implementations of IoT-enabled solutions in the past 12 months alone, this session will focus on experience over the art of the possible. Many can only imagine the most advanced telematics platform ever deployed, supporting millions of customers, producing tens of thousands events or GBs per trip, and hundreds of TBs per month. With the ability to support a billion sensor events per second, over 30PB of warm data for analytics, and hundreds of PBs for an data analytics archive, in his session at @ThingsExpo, Jim Kaskade, Vice President and General Manager, Big Data & Ana...
In the consumer IoT, everything is new, and the IT world of bits and bytes holds sway. But industrial and commercial realms encompass operational technology (OT) that has been around for 25 or 50 years. This grittier, pre-IP, more hands-on world has much to gain from Industrial IoT (IIoT) applications and principles. But adding sensors and wireless connectivity won’t work in environments that demand unwavering reliability and performance. In his session at @ThingsExpo, Ron Sege, CEO of Echelon, will discuss how as enterprise IT embraces other IoT-related technology trends, enterprises with i...
When it comes to the Internet of Things, hooking up will get you only so far. If you want customers to commit, you need to go beyond simply connecting products. You need to use the devices themselves to transform how you engage with every customer and how you manage the entire product lifecycle. In his session at @ThingsExpo, Sean Lorenz, Technical Product Manager for Xively at LogMeIn, will show how “product relationship management” can help you leverage your connected devices and the data they generate about customer usage and product performance to deliver extremely compelling and reliabl...
The Internet of Things (IoT) is causing data centers to become radically decentralized and atomized within a new paradigm known as “fog computing.” To support IoT applications, such as connected cars and smart grids, data centers' core functions will be decentralized out to the network's edges and endpoints (aka “fogs”). As this trend takes hold, Big Data analytics platforms will focus on high-volume log analysis (aka “logs”) and rely heavily on cognitive-computing algorithms (aka “cogs”) to make sense of it all.
One of the biggest impacts of the Internet of Things is and will continue to be on data; specifically data volume, management and usage. Companies are scrambling to adapt to this new and unpredictable data reality with legacy infrastructure that cannot handle the speed and volume of data. In his session at @ThingsExpo, Don DeLoach, CEO and president of Infobright, will discuss how companies need to rethink their data infrastructure to participate in the IoT, including: Data storage: Understanding the kinds of data: structured, unstructured, big/small? Analytics: What kinds and how responsiv...
Since 2008 and for the first time in history, more than half of humans live in urban areas, urging cities to become “smart.” Today, cities can leverage the wide availability of smartphones combined with new technologies such as Beacons or NFC to connect their urban furniture and environment to create citizen-first services that improve transportation, way-finding and information delivery. In her session at @ThingsExpo, Laetitia Gazel-Anthoine, CEO of Connecthings, will focus on successful use cases.
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
The true value of the Internet of Things (IoT) lies not just in the data, but through the services that protect the data, perform the analysis and present findings in a usable way. With many IoT elements rooted in traditional IT components, Big Data and IoT isn’t just a play for enterprise. In fact, the IoT presents SMBs with the prospect of launching entirely new activities and exploring innovative areas. CompTIA research identifies several areas where IoT is expected to have the greatest impact.
Wearable devices have come of age. The primary applications of wearables so far have been "the Quantified Self" or the tracking of one's fitness and health status. We propose the evolution of wearables into social and emotional communication devices. Our BE(tm) sensor uses light to visualize the skin conductance response. Our sensors are very inexpensive and can be massively distributed to audiences or groups of any size, in order to gauge reactions to performances, video, or any kind of presentation. In her session at @ThingsExpo, Jocelyn Scheirer, CEO & Founder of Bionolux, will discuss ho...
SYS-CON Events announced today that GENBAND, a leading developer of real time communications software solutions, has been named “Silver Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. The GENBAND team will be on hand to demonstrate their newest product, Kandy. Kandy is a communications Platform-as-a-Service (PaaS) that enables companies to seamlessly integrate more human communications into their Web and mobile applications - creating more engaging experiences for their customers and boosting collaboration and productiv...
Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been involved at the beginning of four IT industries: EDA, Open Systems, Computer Security and now SOA.
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...
Operational Hadoop and the Lambda Architecture for Streaming Data Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, representing a model of how to analyze rea...
SYS-CON Events announced today that Vitria Technology, Inc. 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. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
When it comes to the Internet of Things, hooking up will get you only so far. If you want customers to commit, you need to go beyond simply connecting products. You need to use the devices themselves to transform how you engage with every customer and how you manage the entire product lifecycle. In his session at @ThingsExpo, Sean Lorenz, Technical Product Manager for Xively at LogMeIn, will show how “product relationship management” can help you leverage your connected devices and the data they generate about customer usage and product performance to deliver extremely compelling and reliabl...
The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
SYS-CON Events announced today that Open Data Centers (ODC), a carrier-neutral colocation provider, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Open Data Centers is a carrier-neutral data center operator in New Jersey and New York City offering alternative connectivity options for carriers, service providers and enterprise customers.