Intergiciels et systèmes distribués

Transcription

1 Intergiciels et systèmes distribués Christophe Gransart IFSTTAR - LEOST 20 Novembre 2012 Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

2 Plan 1 Introduction 2 Service Oriented Architecture 3 Applications for ITS 4 Current and future works

3 Introduction Plan 1 Introduction Definitions 2 Service Oriented Architecture 3 Applications for ITS 4 Current and future works Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

4 Introduction Definitions Goal of a middleware Distributed software to hide data and process distribution hide system and hardware heterogeneity hide data and process distribution offer a common interface for applications (programming model + API) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

5 Introduction Definitions What is a middleware? 1/2 Distributed application = cooperating processes on distributed data processes : description : program execution : process flow (processus) cooperation = communication + synchronization Executing model Programming interface (and/or language) Programming model Developpement tools Runtime environment: system services (for several kind of infrastructures) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

6 Introduction Definitions What is a middleware? 2/2 Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

7 Service Oriented Architecture Plan 1 Introduction 2 Service Oriented Architecture General concepts Communication Service Component Architecture 3 Applications for ITS 4 Current and future works Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

8 Service Oriented Architecture General concepts History of SOA The term SOA was coined in a 1996 research paper by Gartner analyst Yefim V. Natis. SOA is a software architecture that starts with an interface definition and builds the entire application topology as a topology of interfaces, interface implementations and interface calls......soa would be better-named interface-oriented architecture. Despite its early appearance, the term SOA became more prominent some years later around 2002/2003 Web services technologies provided a new interface definition language called WSDL that is suitable for use in a SOA. (say wiz-dell ) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

9 Service Oriented Architecture General concepts SOA features A SOA consists of clients and servers (services) connected by a communication subsystem known as a service bus. Services are defined using formal interfaces (contracts) that hide away implementation details from the client. The bus supports both point-to-point and messaging styles of communication, and supports enterprise qualities of service like security and transactions. Services are often reused by a number of applications. Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

10 Service Oriented Architecture General concepts SOA properties Its interface is defined using a formal contract (for example WSDL or IDL) The service implementation details are unknown to the client ; the only connection (or coupling) between the client and server is the contract The service is self-contained, and can be run with or without other services present Services may be used by other services. The interface is stored in a well-known repository that prospective users can browse Formal contracts, loose-coupling and abstraction of implementation details are key features of a SOA Note: these properties are almost identitacl to the properties if OO architecture (like CORBA) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

11 Service Oriented Architecture General concepts The service bus Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

12 Service Oriented Architecture General concepts The service bus Set of distributed libraries and daemons that facilitate direct and indirect communication between clients and services. Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

13 Service Oriented Architecture General concepts Nothing -really- new!!! SOA associates new terminology with concepts that have been around for some time. The key idea of separating service semantics from service implementation using well defined contracts was already used by CORBA, DCOM and DCE. CORBA and DCOM where inherently object-oriented. SOA can be implemented using existing contract-based client server technologies such as CORBA and DCOM. At the same time, SOA has been used as the motivating force behind the development of new product categories such as the Enterprise Service Bus (ESB) category. Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

14 Service Oriented Architecture General concepts Entreprise Service Bus (ESB) An ESB is a software product that provides underlying communication infrastructure for software components. ESBs provide support for contract-based services using direct (synchronous point-to-point) and indirect (asynchronous messaging) communication paradigms. The enterprise in ESB stresses that the product has features like security and transactions and is suitable for use in a large-scale enterprise. Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

15 Service Oriented Architecture General concepts Entreprise Service Bus (ESB) 2/2 The term emerged around 2003 and has become synonymous with SOA. It has been hijacked by marketers and vendors and liberally redefined to suit their product sets. The industry has settled on the following rule-of-thumb if it doesn t use XML, then it s not an ESB. To qualify as an ESB, a product must use XML; typically this means the web services technologies: XSD and WSDL for contract definition SOAP and XML for protocol payload UDDI for service registry Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

16 Service Oriented Architecture General concepts Features to be an ESB Data modeling with XML Schema; Interface modeling with WSDL; Client and server development tools (code generation from WSDL, libraries, IDE support, etc.) Synchronous point-to-point communication using SOAP/HTTP Asynchronous messaging using SOAP as a payload over a messaging protocol that supports persistence of messages. Message payload transformation using XSLT Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

17 Service Oriented Architecture General concepts What do you need for SOA? A service bus providing point to point messaging A compatible messaging service (if not provided by the bus) Other services: registry, security, transactions... Developer tools (design contracts, develop and deploy services,...) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

18 Service Oriented Architecture General concepts SOA with CORBA ORB + standard services Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

19 Service Oriented Architecture General concepts SOA with ESB Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

20 Service Oriented Architecture General concepts Communication Infrastructure ESB typically uses SOAP as a messaging payload SOAP wraps XML messages in an XML wrapper; as a result SOAP messages are self describing. Messages are transmitted as plain text. Payload transmitted over HTTP or JMS One-way (using SOAP/HTTP or SOAP/JMS) Request-response (using SOAP/HTTP or SOAP/JMS) Document-oriented (using SOAP/HTTP or SOAP/JMS) Publish-subscribe (using SOAP/JMS) Interface described with WSDL Message queuing system (implem ) is proprietary!!! Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

21 Service Oriented Architecture Service Component Architecture Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

22 Service Oriented Architecture Service Component Architecture Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

23 Applications for ITS ITS for cars Plan 1 Introduction 2 Service Oriented Architecture 3 Applications for ITS ITS for cars ITS for public transportation 4 Current and future works Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

24 Applications for ITS ITS for cars STIC for ITS: the solution? Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

25 Applications for ITS ITS for cars Applications of inter-vehicular communications The inter-vehicular communications are used for : Safety (Hazard alert) Traffic Informations (Compute a path according to current traffic) Entertainment (Game, chat, file sharing,...) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

26 Applications for ITS ITS for cars Our application Our application allows to know the informations (position, speed...) on neighbor vehicles. Two specific characteristics for this application : Multi-hop broadcast : allow to receive informations from vehicle beyond of radio range. Messages sent at regulary interval : the informations must be updated with high frequency (ideally 2 Hz) source message ID position speed... forwarder GIS Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

27 Applications for ITS ITS for cars Our application : Client / server + multicast comm Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

28 Applications for ITS ITS for cars CALM Continuous communication for vehicles Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

29 Applications for ITS ITS for cars From : Communication Patterns in VANETs, Schoch et all, IEEE com. Mag 2008 Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38 Communication patterns

30 Applications for ITS ITS for public transportation Plan 1 Introduction 2 Service Oriented Architecture 3 Applications for ITS ITS for cars ITS for public transportation 4 Current and future works Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

31 Applications for ITS ITS for public transportation Train connected Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

32 Applications for ITS ITS for public transportation Resulting architecture The web proxy is modified to adopt a multi-model behaviour A multi-model server is added on the infrastructure side Synchronous model: tunneled Socket connection Asynchronous model : JMS Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

33 Applications for ITS ITS for public transportation Generalization: Multi-Model Architecture A framework for distributed application design Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

34 Applications for ITS ITS for public transportation InteGRail : the context Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

35 Applications for ITS ITS for public transportation InteGRail : on board middleware(s) Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

36 Applications for ITS ITS for public transportation InteGRail : demonstrated qualities E2E information exchange over different technologies while train moves Independence from a single wireless resource Matching application needs to network capabilities Intelligent bandwidth management Opportunistic use of everything available Flexibility of the usage of different techno Connection capabilities like network selection Easy distribution of info from/in train to infrastructure and wrt to business rights Addressing concept Bearer is completely transparent for application Dealing with different train configuration Applicability / feasibility of mobility Differentiated services on the same network infrastructure with qos QoS, assuring best connectivity + mobility Middleware on-board + services Cost improvement through cost optimal usage of wireless resources Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

37 Current and future works Plan 1 Introduction 2 Service Oriented Architecture 3 Applications for ITS 4 Current and future works Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38

38 Current and future works Current and future works Project On-Time Managing train timetables during/after perturbations Distributed architecture C/S arround Europe Work on communication protocol and RailML for specifications Project SECRET Software architecture resilient to EMC perturbations Project SIRSEC Software patterns for safety (distributed) applications New application domains R5G, sensor networks, electro-mobility, soft mobility,... Christophe Gransart (IFSTTAR) GERI STICITS 20 Novembre / 38