Feeds

Time to balance WS-* and REST

Relative needs

The essential guide to IT transformation

The WS-* stack was conceived and driven forward by IBM and Microsoft, with other vendors cooperating on specifications where they had relevant expertise (Verisign on Security, BEA Systems on transactions and so on). The design philosophy was for a relatively simple and efficient basic mode of operation, with optional features added independently of each other.

More recently, though, something else has taken root among developers building distributed applications: Representational State Transfer (REST). As ever with technology, the debate over WS-* and REST has settled on the death of one technology and the rise of the other. The truth, though, lies somewhere in between.

WS-* is a veritable pyramid of specifications piled on top of Simple Object Access Protocol (SOAP) and Web Services Description Language (WSDL). The first addition was Universal Description, Discovery and Integration (UDDI), followed after a couple of years by WS-Security, then WS-Coordination, WS-Transaction, BPEL, WS-Manageability, WS-Addressing, WS-ReliableMessaging, WS-Federation, WS-MetadataExchange.

Both Java Enterprise Edition (Java EE) and .NET have extensive built-in support for serving and consuming web services. Indeed, as this list clearly shows, Java EE 5 includes no fewer than seven web service related specifications. On the Windows platform, Windows Communication Foundation (WCF) is now the default way of using web services from the .NET Framework. Thanks to IBM, WS-* even provides a suitable framework for building grid applications using WS-ReliableMessaging, WS-Distributed Management, WS-Notification, and WS-ResourceFramework. Good overviews of the vast extent of WS-* and related specifications are offered by Thomas Erl and innoQ (among many others). InnoQ also provides a color poster that graphically illustrates the sheer scale of the WS-* architecture.

Before SOAP was invented, back in 1998, there was Dave Winer's XML-RPC. In contrast to WS-*, XML-RPC was designed to make life easier for individuals and small organizations. Therefore it was kept extremely simple and lightweight, at the cost of giving up most of the sophisticated "optional extras" that WS-* offers. Alongside XML-RPC, a whole range of ad-hoc approaches to lightweight web services have sprung up. These are referred to generically as "XML-over-HTTP".

Which brings us to REST, that mysterious acronym that turns up so frequently in today's media, newsgroups, and blogs. REST is not a language, or a protocol, or an architecture. Strictly speaking, it is an architectural style - specifically, the architectural style of the web.

To build a RESTful web service, all you need to know is:

1. What are the resources to be served? (URIs)

2. In what format is the data encoded? (HTML, XHTML)

3. Which methods are supported by each URI? (GET, PUT, POST)

4. What status codes may be returned? (error, warning, information)

REST boils everything down to bare essentials: nouns (resources), verbs (HTTP operations), and data formats (usually XML applications). It is a cardinal principle that every separate method or function should have its own URI; and, ideally, URIs should never change or be withdrawn.

Secure remote control for conventional and virtual desktops

More from The Register

next story
BBC: We're going to slip CODING into kids' TV
Pureed-carrot-in-ice cream C++ surprise
China: You, Microsoft. Office-Windows 'compatibility'. You have 20 days to explain
Told to cough up more details as antitrust probe goes deeper
Windows 7 settles as Windows XP use finally starts to slip … a bit
And at the back of the field, Windows 8.1 is sprinting away from Windows 8
Linux turns 23 and Linus Torvalds celebrates as only he can
No, not with swearing, but by controlling the release cycle
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
This is how I set about making a fortune with my own startup
Would you leave your well-paid job to chase your dream?
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?