Connecting Smart Things through Web services Orchestrations

Connecting Smart Things through Web services Orchestrations Antonio Pintus, Davide Carboni, Andrea Piras, Alessandro Giordano* CRS4 * Università di Cagliari Antonio Pintus - pintux@crs4.it TouchTheWeb’10 - Vienna, 6th July 2010 1 giovedì 8 luglio 2010

Outline • Who, where... • Introduction • Things as Web services (WS) • Pipes • Connecting Things: Pipes as WS Orchestrations • Scenario & prototype • Limitation and future works • Technologies • Conclusions 2 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Who, where... • Antonio Pintus • ICT Group @ CRS4, an interdisciplinary applied research center based in Pula (Cagliari), SARDINIA, Italy 3 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Introduction • In the Web of Things (WoT) vision, things are connected to a pervasive wireless/wired network and can communicate with other objects and services using HTTP-based protocols – Everyday surrounding objects (phones, domestic appliances, advertisement billboards, musical instruments,... ) become nodes of the WoT • De ning simple mechanisms to connect things can foster a huge number of unpredictable applications: – users, objects and networks are the ingredients to build a WoT in which users are also the programmers • The Web is a real platform for Service-Oriented Computing (SOC) and Service-Oriented Architecture (SOA) paradigms – nowadays the Web Services (WSs) and related standards are the enabling technologies for SOC and SOA 4 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Things as Web services? • ...and what if we imagine each thing as a (Web) service? – we could: – have a formal description for functional interfaces (WSDL) – have well-de ned data types (XML Schema) – have a messaging format (SOAP) ? BUT • what about “nature of things “ and connection and communication capabilities? 5 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Assumptions on Things • things must be able to connect to the network and to run a WS stack. Basically in two ways: • the object itself is powerful enough • or, it have to be connected and “driven” by a proxy computer which satis es the requirements • Virtual Things: Web sites, social networks, ... • HTTP-enabled Smart Appliances: smartphones, printers, screens (proxied?) • Internet-enabled Things: TCP/IP, UDP/IP, proxied • Network-enabled Things: No IP protocol: X10, Bluetooth, ZigBee, proxied. • Things not digitally enabled: must have a digital peer, i.e.: a book 6 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Things as Web services! • “Proxied” or not, each Thing is represented by a Web service: • WSDL describes things capabilities as WS operations using XML Schema datatypes • things functionalities can be activated using SOAP messages 7 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Connecting Things • Ok, we have WS representing Things... • The most interesting part is in –connecting them to build brand new applications! –Let users play with connections 8 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Pipes • Concept inspired by pipes in Unix world • A pipe is a simple logical connection between two things implemented as a process that retrieves data from one source, (adapts) and sends to a Pipe := source ----> sink Unix example: ls -l | less snapshot displayImage 9 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Hyperpipes • Basic concept: using a pipe to connect two Things functionalities snapshot displayImage • How to describe hyperpipes? • Things are WS ------> use WS-BPEL to describe and execute pipes 10 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Hyperpipes, de nitions • We de ne: • src: a generic thing functionality (WS operation) which represents a functional capability of the thing returning a value due to its invocation • snk: a generic thing functionality (WS operation) which represents a functional capability of the thing able to accept a value as input • adapter: a generic WS able to provide data transformation or data adaptation functionalities exposed as service operations 11 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Hyperpipes: patterns and... • synchronous: on an thing x is invoked an operation src, (the result is adapted) and then passed as an input to an operation snk exposed by a thing y • asynchronous: the pipe registers itself as a listener for an event produced by an exposed operation src on thing x. When the event is red, the data attached to the event is (adapted and then) sent to the snk operation exposed by the thing y • streaming: a thing y receives from a thing x a stream of data. A suitable real time media transmission protocol should be used after a negotiation and handshaking phase between things. The pipe represents and enables the handshaking step 12 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

...control pattern • A pipe is controlled using a VCR-like interface: start/pause, stop • VCR-like interface is exposed by a Pipe Controller 13 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Pipes as WS-BPEL processes Synchronous Pipe Asynchronous Pipe 14 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Pipes composition: User Interaction • Pipes are composed by users through a simple interaction pattern, using “everyday” objects, where: – Things are “augmented” with a QR Visual Tag (containing the WSDL URL of the related WS) – Users, using an ad hoc smartphone application, are able to: – Point the desired objects (which will be connected) with the smartphone cam – Click to import them in the hyperpipes system – Compose pipes connecting Things functionalities 15 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

• pipe(pipe(snapshot,color-to-gray),TVsink) • pipe(pipe(snapshot,supersampling),TVsink) A Scenario • • pipe(pipe(pipe(snapshot,color-to-gray),supersampling),TVsink) pipe(pipe(pipe(snapshot,supersampling),color-to-gray),TVsink) The same combinations have been tested replacing the synchrono snapshot with the asynchronous one moveDetected. • Three Things: 1. IPWebcam 2. image processing service 3. display/screen • We want to compose a2.pipescenario with multimedia and processing components Fig. Simple that • takes a snapshot from the IPWebcam • makes a color-to-grayscale processing on the image 8 The Prototype • displays the image in the screen In SOA applications one of the main issues are related to service publi service discovery, often faced using registries and directory mechanisms [23]). We adopt a “zero discovery” approach in which the services are rea 16 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010 an environment and it is the user with the point-click-and-compose pa

Prototype • Mainly the prototype is composed of two modules • a smartphone app for the user • a “server” module able to accept incoming “requests” from the smartphone app, compose and execute the pipes 17 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Steps Hyperpipes server 1. User collects Things and smartphone app decodes QR (WSDL URLs) 2. User sends collected WSDL URLs to server 3. Server analyzes WSDLs and sends back potential pipes between things matching the datatypes of discovered operations 4. User selects a particular match and requests the start of the pipe 5. The server composes the WS-BPEL following the pipe pattern and orchestrating the involved WSs 6. User can control the pipe execution using a VCR-like UI: start/pause, stop 18 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

System Architecture Executes Pipes defined as WS-BPEL Processes analyzes WSDLs, proposes pipes, composes WS-BPEL for pipes, deploys them and accepts commands from mobile application 19 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Limitations & future work (1) • Automatic matching of possible pipes given the WSDLs: – next versions will add a complete user responsibility in composing pipes using discovered things • Operations matching relies on shared XML Schemas – For simplicity, XML Schemas are shared and things operations use them to expose datatypes 20 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Limitations & future work (2) • We are investigating for a good compromise between datatypes generality and datatypes matching in our context (semantics?) • Streaming pipes not implemented, yet • We are working for the inclusion of other types of services for representing objects: REST services, RSS/ATOM feeds, ... • WSDL wrappers? • WS-BPEL extensions? 21 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Technology • Architecture written in Java • Apache ODE as WS-BPEL engine • MTOM (SOAP Message Transmission Optimization Mechanism) for optimization of binary data transmission with SOAP • Android platform for mobile application 22 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Conclusions • Representing things as WS implies interesting research topics about a SOA application in the eld of Web of Things, we’ve developed a simple mechanism based on the concept of pipe • Things composition using broad adopted standards (WS-BPEL) ---> inclusion of things in business processes • Main role of users in discovering and composing things • several issues related to “nature” of things emerge: connection, capabilities, proxies, ... • datatypes de nition and matching, messaging, binary data, ... 23 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Contact • Antonio Pintus, pintux@crs4.it • My group @ CRS4: http://geoweb.crs4.it/ • Hyper-pipes: http://geoweb.crs4.it/doku.php?id=Hyperpipes 24 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Thank you for your attention Any questions? 25 Antonio Pintus TouchTheWeb’10 - Vienna, 6th July 2010 giovedì 8 luglio 2010

Connecting Smart Things through Web services Orchestrations

by Antonio Pintus on Jul 08, 2010

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Connecting Smart Things through Web services Orchestrations — Presentation Transcript