|By Yagiz Erkan||
|May 21, 2008 11:00 AM EDT||
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.
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:
- 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 services||Big Web Services|
|Baseline Standards||HTTP, URI, XML||WSDL, SOAP, WS-*|
|Web Philosophy||Use what the Web does well||Use the Web as a transport|
|Documentation||Human oriented||Computer oriented|
|Ease of use||Easy to program||Hard 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.
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
Mar. 25, 2017 01:45 PM EDT Reads: 3,269
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
Mar. 25, 2017 01:30 PM EDT Reads: 1,673
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, will posit that disruption is inevitable for c...
Mar. 25, 2017 01:15 PM EDT Reads: 2,028
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
Mar. 25, 2017 12:45 PM EDT Reads: 1,857
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor - all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
Mar. 25, 2017 12:45 PM EDT Reads: 1,650
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
Mar. 25, 2017 12:30 PM EDT Reads: 1,155
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
Mar. 25, 2017 12:30 PM EDT Reads: 5,051
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
Mar. 25, 2017 12:00 PM EDT Reads: 902
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
Mar. 25, 2017 11:15 AM EDT Reads: 1,519
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, 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 buyers...
Mar. 25, 2017 11:00 AM EDT Reads: 3,539
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
Mar. 25, 2017 10:45 AM EDT Reads: 2,071
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
Mar. 25, 2017 10:00 AM EDT Reads: 2,911
SYS-CON Events announced today that SD Times | BZ Media has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. BZ Media LLC is a high-tech media company that produces technical conferences and expositions, and publishes a magazine, newsletters and websites in the software development, SharePoint, mobile development and commercial UAV markets.
Mar. 25, 2017 09:15 AM EDT Reads: 4,210
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, 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.
Mar. 25, 2017 08:30 AM EDT Reads: 2,031
"I think that everyone recognizes that for IoT to really realize its full potential and value that it is about creating ecosystems and marketplaces and that no single vendor is able to support what is required," explained Esmeralda Swartz, VP, Marketing Enterprise and Cloud at Ericsson, in this SYS-CON.tv interview at @ThingsExpo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Mar. 25, 2017 08:00 AM EDT Reads: 4,077
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Mar. 25, 2017 08:00 AM EDT Reads: 14,013
SYS-CON Events announced today that HTBase will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. HTBase (Gartner 2016 Cool Vendor) delivers a Composable IT infrastructure solution architected for agility and increased efficiency. It turns compute, storage, and fabric into fluid pools of resources that are easily composed and re-composed to meet each application’s needs. With HTBase, companies can quickly prov...
Mar. 25, 2017 06:45 AM EDT Reads: 2,794
Web Real-Time Communication APIs have quickly revolutionized what browsers are capable of. In addition to video and audio streams, we can now bi-directionally send arbitrary data over WebRTC's PeerConnection Data Channels. With the advent of Progressive Web Apps and new hardware APIs such as WebBluetooh and WebUSB, we can finally enable users to stitch together the Internet of Things directly from their browsers while communicating privately and securely in a decentralized way.
Mar. 25, 2017 03:00 AM EDT Reads: 5,775
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
Mar. 25, 2017 12:15 AM EDT Reads: 1,768
What sort of WebRTC based applications can we expect to see over the next year and beyond? One way to predict development trends is to see what sorts of applications startups are building. In his session at @ThingsExpo, Arin Sime, founder of WebRTC.ventures, will discuss the current and likely future trends in WebRTC application development based on real requests for custom applications from real customers, as well as other public sources of information,
Mar. 25, 2017 12:00 AM EDT Reads: 680