1. Service-Oriented Architectures: Potential and Challenges Prof. Dr. Alexander Schill Technische Universität Dresden Chair of Computer Networks  Motivation and Example Scenarios  Basic Technology  Current Trends and Research Challenges

2. Motivation and Example Scenarios

3. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 3 Service Oriented Architectures (SOA): Structure 2. Find via Registry 3. Bind Interaction Requestor Service broker (Registry) Service provider 1. Publish Interface “Distributed, discovery based model to expose and manage a collection of software assets as services”

4. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 4 SOA: Major Advantages  Flexibility Dynamic service selection Variable service orchestration Simple reconfiguration  Integration Universal interfaces based on XML Simple data integration and mapping Coexistence with middleware and application servers  Traditional benefits of distributed systems Decentralization Replication and fault tolerance Parallel execution, scalability etc.

5. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 5 SOA Example: Closed Service Coupling Client (for instance Point of Sale) Client (for instance Automatic Teller Machine) Server (for instance account server) Server (for instance database) Client (for instance Home Access) User interface, pre-processing (thin vs.fat client) Application logic Data management

6. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 6 SOA Example: Complex Business Services Processing (for instance, insurance industry):  Complex workflows and basic service requirements  Basic services and distributed servers Gigabit Network Mobile radio Fast Ethernet Insurance offer Offer verification Client register Special audit Prepare contracts Print documents (parallel) (1) (2) (3) Form editors Audit servers Client management Contract forms Print servers Dept-s for special audit Calculate surcharges

7. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 7 Client Dealer / Sales Advertising agency Engineer (freelance) Manufacturer Bank Video conference Requirements Construction data Product information Advertising material, Online presence Large orders Delivery Payments Request Offers Order Delivery SOA Example: Dynamic Business Web

8. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 8 SOA: General Scenarios Summarized 1.“Closed service coupling”: e.g. automation of internal office tasks, legacy-integration 2.“Complex business services”: access to services of external partners with close contractual relationship 3.“Dynamic Business-Web”: Interaction of many loosely coupled systems; e.g. between manufacturers and suppliers 4.“Agile company”: comprehensive integration, also with customers and partner enterprises

9. Basic Technology

10. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 10 WebServices: Basic Technology for SOA UDDI Registry Web Services Client Web Services Runtime Business Application (using application servers, further distributed internally) WSDL SOAP Discovery Description Firewall WebServices: Software applications accessible via Internet protocols using XML for messaging, description and discovery; W3C standard

11. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 11 Web Services: Basic Building Blocks  Simple Object Access Protocol (SOAP) Remote Procedure Call based on Internet/http and XML  Web Service Definition Language (WSDL) Interface specification language based on XML Can be mapped on all kinds of programming languages  Universal Description and Integration (UDDI) Service Directory for registering and locating web services Global (www.uddi.org) or intranet-based implementationwww.uddi.org  Specific enhancements WS-Secure Conversation (WS-Trust + WS-Security), WS-Discovery, WS-Eventing, WS-Coordination, WS-Addressing, WS-ReliableMessaging, WS-Notification Down-to-earth: RPC + interfaces + directory (like 25 years ago!), but with much better wrapping and integration

12. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 12 WSDL (WebServices Description Language) 3044005 **** John Smith... Call modes: oneway ; request-response (Client/Server) notification ; solicit-response (Server/Client)

13. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 13 Integration with Middleware HTML- Client Java- Client Transaction- Monitors Business software Mainframe- applications Data bases outer Firewall Inner Firewall Web Server HTML- Dokumente HTML- Portals HTML- Dokumente Application Server proprietary Protocols HTTP Stateless-connection Stateful-connection SOAP HTTP Enterprise Application Integration

14. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 14 BPEL: Business Process Execution Language Basic concepts:  Composition of WebServices to complex business processes  Flexible “orchestration”  Support for advanced workflow management; tool support UDDI Servers Control stations Form editors Audit servers Customer relations Contract Mgmt. Print servers Dept-s for special audit Workflow object Document 1 Document 2 Partial document

15. Current Trends and Research Challenges

16. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 16 Trend: Web Services / SOA and the Grid Where web services and the grid meet: Grid services require global integration technology for dynamically sharing and coordinating dispersed, heterogeneous computing resources: WebServices Examples: oOGSA (Open Grid Services Architecture): WSDL integration oWSRF (Web Services Resource Framework) by Akamai, HP, IBM, Tibco etc. oGridbus project: Bank accounting framework via WebServices (by Univ. Melbourne) oNASA´s Information Power Grid oSETI@home (Search for Extraterrestial Intelligence) (by Berkeley Univ.)

17. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 17 WebService Interface of Grid Technology: Example Client UDDI Application Factory Server Search for application factory 1. Configure computational model 2. Create application service Application factory service Directory Application factory Run Model Computational model installed on a high-performance machine Get result data Create 1. Run 2. Get model Information

18. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 18 World-wide Grid Environment Enabled by SOA Application Grid Resource Broker Resource Broker Grid Information Service Grid Resource Broker Grid Information Service database R2R2 R3R3 R1R1 R5R5 RNRN R6R6 R4R4 Selected open issues:  Semantic service selection and matching; software reuse based on ontologies  Global security and privacy policies

19. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 19 Trend: Distributed Multimedia and SOA Example: VidConference System (VidSoft) -Software codecs -Multipoint servers -Java frontend -Middleware/ SOA based

20. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 20 Underlying Service Architecture Interaction QoS- Provision and Realtime Scheduling Transport Protocols Conferencing Client, File and Compression Servers, Gateways Conference Server Application Sharing Session Management Multimedia Components AV Streams Selected open issues:  Integration of QoS into software lifecycle (e.g. UML level, CQML, runtime tools)  QoS behaviour of complex components / BPEL aggregation

21. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 21 Trend: Mobile / Ubiquitous Computing and SOA Product data Central office => Caching Customer Internet Service technician: Open issues: - Adaptation to highly dynamic network and device characteristics - Context management, personalization, multimodal applications Mobile access Mobile Application Scenario

22. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 22 Trend: Mobile / Ubiquitous Computing and SOA Internet- booking Online trip planning Sensor checks online- ticket Planning of tour among fair booths Personal assistant according to customer profile Remote online hotel checkin, restaurant reservation City info. System gives directions Mobile device purchases ticket Internet -> Security and Privacy?

23. TU Dresden, 03.06.2015Prof. Dr. Alexander SchillSlide 23 Thank You! Questions and Discussion