Artificial Intelligence Authors: William Schmarzo, Dan Blacharski, Corey Roth, Jnan Dash, Peter Silva

Related Topics: Artificial Intelligence, Microservices Expo

Artificial Intelligence: Article

JavaOne 2008: SOA, SCA, REST and Comet Discussed

Even though 'Service' comes first in SCA, it doesn't feel like it was designed to build a SOA

DeCare Systems Ireland Blog

Even though 'Service' comes first in SCA (Service Component Architecture), SCA is a distributed component model. It's about designing components (and composites) rather than designing services. It doesn't feel like it was designed to build a SOA. It feels like its main goal was to define a distributed component model. And as we all
know, the distributed component models failed in the past. I think SCA will too.

For the second day of JavaOne my schedule contained technical sessions and BoFs about mostly SOA, SCA, REST and Comet.


I attended two more sessions about SCA:
- Open-Source SOA with SCA and Apache Tuscany
- Open Standards for SOA and Java technology

The second one was a panel session. The host was MC David Chappell of Chappell and Associates and the panellists were David Chappell of Oracle, Mike Edwards of IBM, Steve Jones of Capgemini UK, Patrick Leonard of Rogue Wave, Mark Little of RedHat, Sanjay Patil of SAP AG, Michael Rowley of BEA Systems, Inc., Scott Vorthmann of TIBCO Software Inc., and Peter Walker of Sun Microsystems, Inc.

My first comment is about the name of the panel: It was all about SCA, so why was it not in the title of the session? I think people find a catchy name first and then they come up with the content…

I remember, the first time I read about SCA in late 2005 (a series of articles from IBM, I think), I had the same feeling that I had today: I think SCA is an attempt from Java EE (then-J2EE) vendors to find another way to sell their containers (sorry… “runtimes”) and development tools after the decline of bloated application servers.

Even though “Service” comes first in “SCA (Service Component Architecture)“, SCA is a distributed component model. It’s about designing components (and composites) rather than designing services. It doesn’t feel like it was designed to build a SOA. It feels like its main goal was to define a distributed component model. And as we all know, the distributed component models failed in the past. I think SCA will too.

SCA promises component reusability. However, one of the dangers that I saw today was reliance to a single vendor’s runtime. I haven’t tested it personally but the panelists’ answers made it clear that there’s no guaranteed portability between vendors’ runtimes. It is clearly said that “SCA is about interoperability and not about portability”. Not to mention .NET, which doesn’t support SCA. So, it’s mainly a Java thing. I know one can write components in JavaScript and even in BPEL but in JavaOne, it’s about Java, right :). Not sure who would like to write a component in JavaScript.

How real is SCA? I have only seen or heard of a few case studies. And I found it odd that, among the panelists, Steve Jones was the only one developing a production application using SCA. His comments showed why one can get easily confused about what SCA really is. He said that SCA helps in organizing the development teams and operations. And it was also said that it’s an architectural and operational technology. But I’m sure SCA didn’t start with this intent. Maybe, it’s trying to fit a niche now but a technology won’t succeed by getting away from the developers. Furthermore, the concept of an SCA module that can export and import other modules is very similar to OSGi’s. So, if you’re looking for modularity in Java, I’d recommend OSGi just as if you’re looking for Web Services, I’d recommend Resource-Oriented RESTful Web Services.

These sessions attracted a lot of people, the halls were completely full. And it is encouraging that the people I talked to at the end of the sessions were as skeptical as I was. I think, as an industry, we’re adopting an increasingly pragmatic approach to new technologies and techniques. How can’t it be that way? 24 hours ago, we attended a talk about the case study of a grid-enabled SOA capable of handling 35 million transactions without SCA, JBI, BPEL, WSDL etc. Another question that came to my mind was: Why haven’t we had case studies about SCA or JBI? I have a few more sessions to attend until the end of JavaOne… We’ll see…


The technical session entitled “It’s All About the SOA: RESTful Service-Oriented Architecture at Overstock.com” was my only one about REST (Representational State Transfer) today. And it was a case study presented by Ian Robertson and Sean Landis.

Overstock.com started, probably like most of the now-big companies who built their business on the Web, with a monolithic, quickly put together code. It was written in C. This reminded me of my first Web development days in 95-96 when we used to do CGI development in C. I can’t say “Good Old Days!” because the days are much better now. At least at work :).

Overstock.com is a Utah-based online retailer. It was founded in the late 90s under the name Discounts Direct and underwent a name change in 1999. They used the Web to sell surplus and returned merchandise.

When it was time to improve their system, they switched to Java and then to a SOA. Their main motivations to put in place a modular service oriented architecture were:

- To use web services
- To better isolate some sensitive data
- Facilitate concurrent development across various teams

They also had a Web site for mobile clients that could take advantage of common services.

As part of their analysis, they looked at various underlying technologies to build their SOA on:

- Java RMI: It was a simple option but it had poor support for load balancing and failover.
- JERI (Jini Extensible Remote Invocation): It was too complicated
- Web Services: They were ideal for a Web development house. However, like many others, Overstock.com found SOAP and WS-* too heavy, therefore REST looked very promising.

REST stands for Representational State Transfer and it started as the PhD dissertation of Roy Fielding, who is also one of the principal authors of the HTTP specification. It is a style not a standard. It is a set of design criteria but not an architecture. And its main concept is to fully use HTTP rather than using only one of its actions as a mere envelop to pass XML data. This idea includes using HTTP methods such as GET, POST, PUT, DELETE and HEAD as they were intended to be used, at first, when a bunch of scientists were using by-then-non-public Web to collaborate. Even though it’s back to basics, this constitutes a major mindset-shift in programming for the Web because most of the Programmable Web isn’t used the same way as we browse the Web using a browser.

The presenters continued their talk by explaining the architectural style of REST (Client-server, layered, stateless, cacheable) and the importance of the concept of Resource. A resource is some data that can be held on a support and represented as a data stream when it’s requested. This can be an image, a document, the result of a computation etc. A resource has to have a URI, therefore the target of a URI is a resource. One of the beauties of a resource accessible by a URI is that the URI can map to different representations of the same data. For example, if the current temperature of Cork (Ireland) is requested, the response can be a text saying “Rainy, 15″ or an image of a rain cloud with “15″ printed on it.

REST has some principles and best practices:

- A URI for each resource
- Logical URIs over physical ones. For example it’s better to have:
rather than:
- Nouns, not verbs are used as part of the URI (http://www.example.com/java/jdk/version)
- GET has no side-effect on the system, it doesn’t cause any modification etc. The client “gets” some data, that’s all. Therefore GET is a safe action.
- To link responses to other requests by using links in the responses.
- To minimize the use of query string
- “/” represents concepts like “parent/child” or “whole/part
- Gradual unfolding: A resource representation should contain links to get more details.
- GET is the method to use when the client needs a resource representation, not the POST method.

In the RESTful world, the SOAP-based Web Services are called Big Web Services. The matrix below compares them:

RESTful web servicesBig Web Services
Baseline StandardsHTTP, URI, XMLWSDL, SOAP, WS-*
ConformanceInternet StandardsWS-I
Web PhilosophyUse what the Web does wellUse the Web as a transport
DocumentationHuman orientedComputer oriented
Ease of useEasy to programHard without tool support

Going back to Overstock.com: They are an agile development house. They wanted to use Java SE to develop Web Applications without magic. They favored simplicity and performance (cut off the fluff: SOAP). The deployment of their application became extremely simple as well just by using a simple Servlet container. They adopted Restlet as their REST framework. Furthermore, as part of their internal development framework, they extended it and they contributed back their additions.

I’m going to open a bracket about Restlet here, because it really deserves it. Restlet is a REST framework in Java created by Jérôme Louvel and first released publicly at the end of 2005. He developed the first version of his framework that was going to become Restlet, on top of the Servlet API. Then, he decided to bypass the Servlet API and developed the first Restlet connector that issued direct REST uniform calls. Later he split the Restlet project in two:
- Restlet API: Generic classes
- Noelios Restlet Engine: Reference implementation, server and client connectors, etc.
Today, Restlet provides a solid ground to build RESTful Java applications.

So, in Overstock.com, they adopted REST but they had to spend some effort to create the mental shift to Resource-oriented architecture. And they found that testing and team coordination (including release and deployment coordination) became very important.

Some lessons learned:

- SOA has a cost of adoption. The project team needs to be educated.
- Resource-orientation and REST require a different mindset (compared to the traditional Web App development). Richardson and Ruby’s RESTful Web Services book was the required reading (It is an excellent book. If you’re in Web development, I definitely recommend it).
- Looking back, they think they should have done a better job on the business analysis.
- Version management has always been a challenge.

More Stories By Yagiz Erkan

Yagiz Erkan is lead Technical Architect, DeCare Systems Ireland, since 1998, and has over 10 years industry experience. He is also the development champion within the company and is responsible for guiding and directing the technical evolution of the software development processes at DSI. He manages an architectural group who ensure that the most up to date and suitable practices are utilized, leading to the delivery of high quality applications and solutions.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of the 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to gre...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform. In his session at @ThingsExpo, Craig Sproule, CEO of Metavine, demonstrated how to move beyond today's coding paradigm and shared the must-have mindsets for removing complexity from the develop...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
"Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.