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Web Oriented Architecture. Presented at Gluecon 2010 by Aaron Fulkerson
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Web-Oriented ArchitectureOriginally presented at Gluecon 2010
Aaron Fulkerson
@roebot
About MindTouch
• Open source company
• Strategic documentation platform
• And a new kind of ECM
• Projects oDReAM
o SGMLReader
oMindTouch Core/2010
What is WOA?
WOA in a Nutshell
REST WWWWOA ( )
*Originally coined by Nick Gall @ironick (Gartner) 2005
REST Cheat Sheet
• Representational state transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web. (source: Wikipedia)
• Principleso Everything is a RESOURCEo Every resource has a REPRESENTATIONo Every resource has a canonical NAMEo There is a finite VOCABULARY of actionso State transitions require DISCOVERY
WOA in a Nutshell
• Information is represented as Resources• Resources are identified by URIs• Resources are manipulated via HTTP• Contracts are implicit in the representation of
the resource• Interfaces are generic
REST applied to WWW
REST WOA or REST(WWW)
Resource Web Service
Representation XML, JSON, SPHP, …
Name URI
Vocabulary HTTP methods
Discovery HTML, XML, Atom, …
God Bless HTTP
• Leverage HTTP to its full potentialo Simple: verbs, headers, status codeso Scalable: every operation is self-contained
• Every browser can be a cliento Easy discoveryo Easy debugging
• Build on existing (standard) infrastructureo Proxieso Load balancers
Of Clients and Servers
• In WOA…o Services rely on other servicesoCommunicate over HTTPo Are clients of some resources and servers of
otherso Extensibility, Scalability == Interconnection
Web APIs everywhere
• APIs allow others to integrate with youo Simplifies integrationo Frees you from custom engineering for partners
• Fosters “Unexpected reuse”• Let others provide features not on your
roadmap
Most APIs are Data Island Veneer
• Closed, specific internal architecture• Only exposes use cases directly envisioned
by API designers• Only outward facing• Do not aid internal integration stories
Web APIs, WOA style
• Connect internal systems over REST serviceso Internals become generico Extensibility becomes application neutralo Location, availability and breadth of
dependencies can take advantage of HTTPo Enables internal innovation without requiring
integration work
API first!
• Don’t expose a feature after the fact via an API
• Build an API for every feature firsto Better understanding the feature by internal and
external consumersoNo blind spots of API inaccessible parts
A word about MindTouch Core/2010
Open source collaboration platform
for the enterprise and the web• Built with Mono/.NET and PHP• Runs on SLES, RHEL, Debian/Ubuntu,
Windows and even Solaris• Downloaded over 500,000 times• Used by over 15M people• MindTouch is API first!
Application Architecture
MindTouch DReAM
Host
Core
Varnish
LucenePubSub
Package
PubSub
Subscriptions
Authentication Extensions Scripts
Storage
MindTouch API
http://developer.mindtouch.com/Deki/API_Reference
• Exposes capabilities of MindTouch as web services
• MindTouch web UI uses APIo Anything the web UI can do, a third party can do
• Uses REST for extensibility• Service Discoverability
o@blueprinto@about
Some links
• http://developer.mindtouch.com/en/ref/MindTouch_API (glorious)
• http://developer.mindtouch.com/@api/deki/@blueprint• http://developer.mindtouch.com/@api/deki/@about• http://developer.mindtouch.com/@api/deki/pages/3228• http://developer.mindtouch.com/User:AaronF
– {{web.xml("http://developer.mindtouch.com/@api/deki/pages/3228/contents?format=xhtml")}}
• http://developer.mozilla.org• www.Shelfari.com• www.Whorunsgov.com
Extensibility
• Web Serviceso Standalone services
• Local or remote• Only requirement: provide a REST API
o Extensions• Hosted or remote
oDekiScript Extensions• Hosted or remote• Native or script
Architectural Benefits
• 100% API coverage there’s an API for that
• Uniform programming modeloOne model to rule them all!
• Agnostic extensibilityo Any programming languageoHosted anywhere on the network
• Flexible deployment topologiesoMany sites on one machineoMany machines for one site
The DReAM REST framework
• MindTouch is built on DReAM• DReAM optimizes REST calls within
framework, by providing an in-process HTTP pipelineo Local REST calls do not hit the wireo Serialization/Deserialization only required for out
of framework callso Local Routing of bypasses DNS
WOA makes your life easier
• Simplifies extensibility, scalability• Reduces development time for new features• Reduces engineering time spent on
integration• Creates opportunity for mash-ups and other
unforeseen user stories
