Agent Paradigm: a Promising Approach to Enterprise Application Integration

1. Agent Paradigm: a Promising Approach to Enterprise Application Integration Paola Turci turci@ce.unipr.it

2. Outline of the Lecture The Context Consolidated Approaches & Open Issues Research Directions  An Agent-Based SOA  P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

3. Today’s Enterprise Application Issues • Ability to change IT quickly to fit business needs • To improve responsiveness and efficiency • Demand for high-levels of interoperability • Organizations feel the need to support interoperability between separately designed systems • Most enterprises are very heterogeneous • Organizations want applications to have broader reach P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

4. Business Performance Management Institute’s Survey - 2006 • 11 percent of executives say they're able to keep up with business demand to change technology-enabled processes — 40 percent of which, according to the survey, are currently in need of IT attention • 36 percent report that their company's IT departments are having either "significant difficulties" (27 percent) or "can't keep up at all" (9 percent) P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

5. What Characterizes Enterprise Applications? • Usually • Involve persistent data • There is a lot of data • Many people access data concurrently • A lot of user interface screens • Need to integrate with other enterprise applications P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

6. Enterprise Application Integration • The task of making disparate applications work together • EAI challenges: • Applications can run on multiple computers, which may represent multiple platforms, and may be geographically dispersed • Networks are slow and unreliable • Applications may run outside of the enterprise by business partners or customers • Applications are quite dissimilar • Changes are inevitable P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

7. Enterprise Application Integration (II) • Criteria that should be considered when choosing and designing an integration approach • Application coupling • Intrusiveness • Technology selection • Data format • Data timeliness • Data or functionality • Remote Communication • Reliability P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

8. Outline of the Lecture The Context Consolidated Approaches & Open Issues Research Directions  An Agent-Based SOA  P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

9. Integration Approaches • Four main integration styles consolidated • File Transfer (70s) — applications share files • Good physical decoupling • Language and system independent • No extra tools or integration packages are needed • An important decision is what format to use (XML) • Drawbacks • Effort is required to produce and process files • Need to agree on the filename, location and format, the timing of when it will be written and read, and who will delete the file • Possible semantic dissonance • Systems can get out of synchronization P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

10. Integration Approaches (II) • Shared Database (80s) — applications share the same database schema, located in a single physical database • Use of SQL-based relational databases • Consistent data • Drawbacks • Integration of data • Difficult to find a common representation • Database may become a performance bottleneck P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

11. Integration Approaches (III) • Remote Procedure Invocation (90s) — Each application seen as a large-scale object or component with encapsulated data • The communication is synchronous • Goal • Make RPC look as much like local PC as possible • Advantages • Data exchanged only as needed • Integration of business functions, not just data • Weaknesses • Big differences in performance and reliability between remote and local procedure calls • Latency • Lack of control over other systems • Applications tightly coupled as a local method call P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

12. Integration Approaches (IV) • Messaging — applications publish messages by using a common messaging system • Agreement on the message format. • The communication is asynchronous • Pros: • Reliability • Loose coupling • But… fewer assumptions mean that more is left to do for the developer • Correlation of related messages (e.g. request and response) • Maintaining state • Determining order of events, to re-establish the message sequence • Complex programming model … figuring out what to do next • Main drawback: • Individual systems are wired togethervia a message flow P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

13. … remarks about coupling Coupling is not inherently good or bad • Coupling is a measure of dependency between applications • Technology Dependency • Location Dependency • Temporal Dependency • Data Format Dependency • Tightly Coupled Systems • Make many assumptions about each other • Well suited for internal communication inside of an application • Well suited for “near” communication, with control over both sides of the interaction • Generally more efficient, easier to develop and debug P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

14. Forrester Research* “… SOA's ability to save IT costs and, more importantly, build business flexibility has driven broad adoption: 53% of enterprises are using SOA now or will use it by the end of 2006, and nearly one-half of large enterprises are using SOA for strategic business transformation. SOA is applicable to a broad range of business and technical scenarios, and every organization should investigate SOA and learn where and how it can benefit them” May, 2006Topic Overview: Service-Oriented Architectureby Randy Heffner, Larry Fulton * An independent technology and market research company that provides its clients with advice about technology's impact on business and consumers P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

15. CIO Magazine* “… According to a recent Forrester Research survey, 46 percent of large-enterprise SOA users (and about 27 percent of SOA users at midsize and smaller enterprises) said they're using SOA to "achieve strategic business transformation." Surveys from other research companies report the same enthusiasm …” BUT “… SOA is far from being a proven concept (only 16 percent of companies in the Aberdeen survey have more than 24 months of experience with SOA technologies), and the companies that have had the most success with it so far are those that alwayshave success with technology: big companies with big IT budgets whose business is technology-based (think telecom and financial services). They also tend to have supportive, technologically sophisticated business leaders …” * “The Truth About SOA” June 15, 2006 P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

16. What is SOA? • A form of distributed systems architecture, typically characterized by the following properties:   • Logical view: The service is an abstracted, logical view of actual programs, databases, business processes, etc., defined in terms of what it does … • Message orientation: The service is formally defined in terms of the messages exchanged between provider agents and requester agents, and not the properties of the agents themselves. … A key benefit of this concerns so-called legacy systems • Description orientation: A service is described by machine-processable meta data. … only those details that are exposed to the public and important for the use of the service should be included in the description. The semantics of a service should be documented, either directly or indirectly, by its description.   • Granularity: Services tend to use a small number of operations with relatively large and complex messages. … • Platform neutral: Messages are sent in a platform-neutral, standardized format delivered through the interfaces (XML) … P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

17. … what is the point? • Most of the technology and market research companies, which provides their clients with advice about technology's impact on business and consumers, agree on the fact that the adoption of a SOA paradigm is strategic and should be part of the most forward-looking software projects. Nevertheless … the paradigm shift is still quite challenging!!! P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

18. Widgets & Gadgets 'R Us: An Example • An online retailer that buys widgets and gadgets from manufacturers and resells them to customers • Requirements: • Take Orders: customers can place orders via Web, phone, or fax • Process Orders: processing an order involves multiple steps: verifying inventory, shipping the goods, and invoicing the customer • Check Status: customers can check the order status • New Catalog: suppliers update their catalog periodically. WGRUS needs to update pricing and availability based on the new catalogs • Announcements: customers can subscribe to selective announcements from WGRUS • Testing and Monitoring: operations staff needs to be able to monitor all individual components and the message flow between them Source : G. Hohpe, B. Woolf Enterprise Integration Patterns Addison Wesley P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

19. Widgets & Gadgets 'R Us (II) WGRUS IT Infrastructure Source : G. Hohpe, B. Woolf Enterprise Integration Patterns Addison Wesley P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

20. Taking Orders A message-oriented middleware solution to streamline the order entry process Source : G. Hohpe, B. Woolf Enterprise Integration Patterns Addison Wesley P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

21. Processing Orders • A typical implementation of a distributed business process • Main disadvantage of such a solution : • Individual systems are wired togethervia a message flow Source : G. Hohpe, B. Woolf Enterprise Integration Patterns Addison Wesley P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

22. Process Manager • Individual systems turned into shared business functions; can be accessed as services • Increases reuse and simplifying maintenance • Interlinked by statically or dynamically defined workflows • Services orchestrated via a Process Manager Source : G. Hohpe, B. Woolf Enterprise Integration Patterns Addison Wesley P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

23. Process Manager (II) • To turn the WGRUS IT infrastructure into an SOA it is necessary to add facilities to look up ("discover") a service from a central registry • In order to participate in this SOA, each service would have to provide additional functions • e.g. to expose an interface contract that describes the functions provided by the service • Each request-reply service also needs to support the concept of a return address P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

24. … the Vision Web Application Legacy SW HTTP CORBA Business Process ODBC Java Application RMI Data Base WS-BPEL JCA .NET REMOTING ERP, CRM .NET Application Web Service P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

25. XML – SOAP – WSDL – UDDI • Rely on static descriptions of service interfaces, forcing consumers to find and bind services at design time • Do not address runtime service selection based on a dynamic assessment of nonfunctional attributes • They guarantee syntactic interoperability, but they fail to provide semantic operability P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

26. Open Issues • This innovative idea brings with it new outstanding opportunities but also new great issues How to efficiently discover Web services How to allow and facilitate their composition P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

27. Outline of the Lecture The Context Consolidated Approaches & Open Issues Research Directions  An Agent-Based SOA  P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

28. Agent Community • Evidence from several research studies that agents could represent a suitable technology which can be used to meet the performance needs for innovative business applications • Several papers attest the current interest in using agents for developing e‑business applications, business process management and enterprise application integration • Different works have shown how agent technology can be leveraged if used together with other technologies: semantic Web, Web services, rule engine and workflows P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

29. P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

30. OMG & SOA • 2006, OMG launched a SOA SIG. • Primary goals: • To support an MDA approach to SOA that links architectural,  business and technology views of services, including Business Process  Management (BPM) and Event-Driven Architecture (EDA). • Identify and foster development of OMG modeling standards for SOA that integrate with and complement standards developed by other organizations such as W3C, Open Group and OASIS. • To improve awareness and understanding of SOA by OMG members. • To coordinate SOA related efforts within OMG. But…little has been done!!! P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

31. FIPA - Agents and Web Services Interoperability Working Group • Since 2005, FIPA is an IEEE Computer Society standards organization • Interoperability and standardization efforts • The primary objective of AWSI WG is to fill the interaction gap between agents and web services. Agents should be able to locate and interact with web services seamlessly and vice versa But … most of the work has to be done!!! P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

32. Research Directions for Service-Oriented Multiagent Systems • Four major trends will drive SOC and MAS research in the next decade • Online ontologies – shared representations are emerging as models for real-world entities • Ubiquitous computing • Computational behaviours provided in the form of Web services and service architecture • Widespread availability of sensors and effectors – control of physical world • SOC represents an emerging class of approaches with MAS-like characteristics for developing systems in large-scale open environments Huhns, M., Singh, M., Burstein, M., Decker, K., Durfee, E., Finin, T., Gasser, L., Goradia, H., Jennings, N. R., Lakartaju, K., Nakashima, H., Parunak, V., Rosenschein, J., Ruvinsky, A., Sukthankar, G., Swarup, S., Sycara, K., Tambe, M., Wagner, T. and Zavala, L. (2005) Research directions for service-oriented multiagent systems. IEEE Internet Computing 9(6) pp. 52-58. P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

33. W3C Workshop on Frameworks for Semantics in Web Services June 2005 • Two concrete proposals: • Elicit some concrete challenges (“pain points”) • Bring together the developers of the more comprehensive technology efforts to define simple specifications for the “low-hanging fruit” that is common to all of their approaches • Semantic annotation in WS descriptions (such as typing of inputs and outputs, expression of preconditions and effects of primitive actions) • A simple incremental set of extensions to WSDL to indicate references to these elements • … two years after SAWSDL • Hierarchical classification of services for purposes of advertising and discovery • Expression of “non-functional” properties such as QoS • Possibly simple uses of rules in expressing policies of contractual commitments • … … two years after Web Services Policy P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

34. Outline of the Lecture The Context Consolidated Approaches & Open Issues Research Directions  An Agent-Based SOA  P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

35. … the new Vision Web Application Legacy SW HTTP CORBA ODBC Java Application RMI Data Base MAS JCA .NET REMOTING ERP, CRM .NET Application P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

36. Agents’ Role • The central role that agents should play in a SOA scenario is • To efficiently support distributed computing • To allow the dynamically discovering and composition of Web services • To be successful, it is crucial to appropriately engineer and integrate agent technology with other strategic technologies P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

37. Ontologies “An explicit specification of a conceptualisation” [Gruber93] • Research community contributions have been mainly devoted to cope with four different issues: • Formal definition of a standard language for expressing semantics on the web (OWL) • OWL Group to refine and extend Web Ontology Language • Development of tools to engineer ontologies • Two co-existing realities: • Semantic web • Object-oriented systems • An ontology representation more in line with the OO data model P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

38. Ontologies (II) • Development of ontological supports for MASs • A communication support to perform the proper semantic checks on a given content expression • e.g. the JADE ontological support • Definition of specifications for semantic Web services • Goal: providing a semantic layer based on the WS standards • relying on WSDL for WS invocation • expanding UDDI for WS discovery • Semantic Annotations for WSDL and XML Schema; W3C recommendation, August 2007 • OWL-S – an OWL-based service ontology supplying a core set of markup language constructs • … P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

39. Modelling Level:OWL and UML Compared • UML structure is formally quite different from OWL: • Both OWL and UML are based on classes • Key difference: the notion of Property • At first glance, the OWL property appears to be the same as UML association or attribute, But … • OWL: • Properties are first-class modelling elements • UML: • An association is defined in terms of association ends, which must be related to a classifier • An attribute is always within the context of a single class In OWL it is possible to state assertions on properties that have no equivalent in UML P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

40. Implementation Level:OWL and Java Compared • Research community followed two major directions to express the OWL semantics using an OO language • The definition of a meta-model that closely reflect the OWL syntax and semantics. • e.g. the modelling APIs of Jena and OWL API • The use of the Java Beans API to realize a complete mapping between the two models [Kalyanpur et al]. • PropertyChecker classes to support the semantics of the property, axioms and restrictions • This approach lacks an explicit meta-model P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

41. A Semantic Framework for MASs • With the aim of providing a support for semantic Web services discovery and invocation • WSs are supplied with a semantic description • The discovery and invocation phases make use of an abstract description of the service, based on ontological concepts belonging to the domain ontologies • Discovery: semantic UDDIs are responsible of the semantic search • Invocation: mapping between the semantic description of the service and its real invocation • WSDL document, from the discovery phase, is used in the invocation phase • Mapping exploiting XSLT stylesheets (e.g MINDSWAP, OWL-S API project) P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

42. Semantic UDDI • UDDI has two crucial limitations • Its search mechanism • WSs functionality can be described using classification schemes like NAICS, UNSPSC etc. • The usage of XML to describe its data model • Lack of explicit semantics • But … UDDI has enough support for the registration of semantically annotated resources • Mapping of ontology concepts to UDDI data model using tModel structure • New API to support semantic discovery of registered resources • Semantic discovery algorithms P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

43. Semantic Search in UDDI • Based on an externally created and operated matchmaker • Semantic data are stored outside of UDDI • A mapping of an OWL-S profile to the UDDI data model • Changes to UDDI APIs for support of semantic search M. Paolucci, T. Kawamura, T.R. Payne, K. Sycara, “Importing the Semantic Web in UDDI”, Proceedings of E-Services Semantic Web Workshop (ESSW 2002), 2002 N. Srinivasan, M. Paolucci, K. Sycara, “An Efficient Algorithm for OWL-S Based Semantic Search in UDDI” Semantic Web Services and Web Process Composition, First International Workshop, SWSWPC 2004: 96-110 M. Klusch,, B. Fries, K. Sycara, “An Efficient Algorithm for OWL-S Based Semantic Search in UDDI” AAMAS 2006 P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

44. Business Process Management • WSBPEL is the new standard for orchestrating business process using web services • Joint IBM/Microsoft proposal, being standardized through OASIS • There are some competing languages, e.g. BPML • Supported by more platform vendors than its predecessors that tried to achieve similar goals, such as ebXML • BPEL is supported by Microsoft, IBM, BEA, SAP, Hewlett- Packard, Oracle, Siebel, and others. • Choice of process engines • Useful in defining both concrete and abstract processes • Each activity is represented as a service with a WSDL interface P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

45. Goal-Oriented Autonomic Business Process Management • Interesting talk on Tuesday afternoon Giovanni Rimassa, Birgit Burmeister “Achieving Business Process Agility in Engineering Change Management with Agent Technology” P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

46. Limitations of Description Logics • Description Logics provides a snapshot of the World • Describe objects in a given time frame • They are intrinsically very static • Difficult to represent processes (sequences of situations) • There is no explicit notion of variables and rules • It is impossible to say that X father Y and Y father Z  X grandfather Z • Lots of research has happened to extend RDF/OWL (SPARQL, SWRL,, …) • Integration of Rule-Based and Agent-Based Programming (e.g D4J) P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

47. Concluding Remarks P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

48. May Agents Enhance SOA? • Integration between local and global management • Single agent cope with local problems • Different agents can cooperate to cope with global problems • Communication overhead • Agent distribution • Agent mobility • System dynamic upgrading • Agent evolution • Code mobility • Robustness and fault tolerance • Agent replication P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

49. How Should an Innovative Agent-Based SOA Be? Features Difficulties • Enhancing interoperability through ontologies • Enhancing security through OASIS-W3C standards • Enable the use of workflow / rule engines • Ontology management software are not efficient • Security solutions for distributed systems are limited P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007

50. Agents & Workflow Integration Workflow Technologies Workflow & agent based systems • High level means for service composition • High level means for system programming when supported by visual tool • Well known standards (i.e.,xpdl ,WSBPEL, …) • Large set of software tools available • Workflow can be used to program agent systems at a high abstraction level • Workflow execution can be optimized by partitioning it among agents • Agents can act as workflow engines • System evolution can be realized updating the workflow to be executed P. Turci - Agent Paradigm: a Promising Approach to Enterprise Application Integration WOA 2007