In this presentation, we identify two major issues related to Web service composition: the lack of formal specifications for services and service compositions and the inability of current service composition approaches to support dynamicity and QoS-awareness in an effective and scalable way. We analyze the underlying research challenges for each of these issues and propose a tentative research plan to address them.
Deriving Specifications for Composite Web ServicesGeorge Baryannis
We address the problem of synthesizing specifications for composite
Web services, starting from those of their component services.
Unlike related work in programming languages, we assume the
definition of the component services (i.e. their code) to be
unavailable --- at best, they are known by a specification which
(safely) approximates their functional behavior. Within this
scenario, we deduce general formula schemes to derive specifications
for basic constructs such as sequential, parallel compositions and
conditionals and provide details on how to handle the special cases of
loops and asynchronous execution. The resulting specifications facilitate
service verification and service evolution as well as auditing processes,
promoting trust between the involved partners.
Deriving Specifications for Composite Web ServicesGeorge Baryannis
We address the problem of synthesizing specifications for composite
Web services, starting from those of their component services.
Unlike related work in programming languages, we assume the
definition of the component services (i.e. their code) to be
unavailable --- at best, they are known by a specification which
(safely) approximates their functional behavior. Within this
scenario, we deduce general formula schemes to derive specifications
for basic constructs such as sequential, parallel compositions and
conditionals and provide details on how to handle the special cases of
loops and asynchronous execution. The resulting specifications facilitate
service verification and service evolution as well as auditing processes,
promoting trust between the involved partners.
Continuous Integration and Continuous Delivery to Facilitate Web Service TestingCognizant
Quality assurance (QA) organizations can dramatically upgrade web services testing by applying continuous integration and continuous delivery/deployment (CI/CD) techniques derived from DevOps and by deploying software such as Jenkins, LISA, Maven, Cucumber and Gherkin.
Fluent Calculus-based Semantic Web Service Composition and Verification using...George Baryannis
We propose a composition and verification framework for Semantic Web Services specified using WSSL, a novel service specification language based on the fluent calculus, that addresses issues related to the frame, ramification and qualification problems. These deal with the succinct and flexible representation of non-effects, indirect effects and preconditions, respectively. The framework exploits the unique features of WSSL, allowing, among others, for: compositions that take into account ramifications of services; determining the feasibility of a composition a priori; and considering exogenous qualifications during the verification process. The framework is implemented using FLUX-based planning, supporting compositions with fundamental control constructs, including nondeterministic ones such as conditionals and loops. Performance is evaluated with regard to termination and execution time for increasingly complex synthetic compositions.
Location-Aware and Personalized Collaborative Filtering for Web Service Recom...1crore projects
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Dot Net
DOTNET Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
Java Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
ECE IEEE Projects 2015
1. Matlab project
2. Ns2 project
3. Embedded project
4. Robotics project
Eligibility
Final Year students of
1. BSc (C.S)
2. BCA/B.E(C.S)
3. B.Tech IT
4. BE (C.S)
5. MSc (C.S)
6. MSc (IT)
7. MCA
8. MS (IT)
9. ME(ALL)
10. BE(ECE)(EEE)(E&I)
TECHNOLOGY USED AND FOR TRAINING IN
1. DOT NET
2. C sharp
3. ASP
4. VB
5. SQL SERVER
6. JAVA
7. J2EE
8. STRINGS
9. ORACLE
10. VB dotNET
11. EMBEDDED
12. MAT LAB
13. LAB VIEW
14. Multi Sim
CONTACT US
1 CRORE PROJECTS
Door No: 214/215,2nd Floor,
No. 172, Raahat Plaza, (Shopping Mall) ,Arcot Road, Vadapalani, Chennai,
Tamin Nadu, INDIA - 600 026
Email id: 1croreprojects@gmail.com
website:1croreprojects.com
Phone : +91 97518 00789 / +91 72999 51536
Location-Aware and Personalized Collaborative Filtering for Web Service Recom...1crore projects
IEEE PROJECTS 2015
1 crore projects is a leading Guide for ieee Projects and real time projects Works Provider.
It has been provided Lot of Guidance for Thousands of Students & made them more beneficial in all Technology Training.
Dot Net
DOTNET Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
Java Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
ECE IEEE Projects 2015
1. Matlab project
2. Ns2 project
3. Embedded project
4. Robotics project
Eligibility
Final Year students of
1. BSc (C.S)
2. BCA/B.E(C.S)
3. B.Tech IT
4. BE (C.S)
5. MSc (C.S)
6. MSc (IT)
7. MCA
8. MS (IT)
9. ME(ALL)
10. BE(ECE)(EEE)(E&I)
TECHNOLOGY USED AND FOR TRAINING IN
1. DOT NET
2. C sharp
3. ASP
4. VB
5. SQL SERVER
6. JAVA
7. J2EE
8. STRINGS
9. ORACLE
10. VB dotNET
11. EMBEDDED
12. MAT LAB
13. LAB VIEW
14. Multi Sim
CONTACT US
1 CRORE PROJECTS
Door No: 214/215,2nd Floor,
No. 172, Raahat Plaza, (Shopping Mall) ,Arcot Road, Vadapalani, Chennai,
Tamin Nadu, INDIA - 600 026
Email id: 1croreprojects@gmail.com
website:1croreprojects.com
Phone : +91 97518 00789 / +91 72999 51536
WEB SERVICE COMPOSITION IN DYNAMIC ENVIRONMENT: A COMPARATIVE STUDYcscpconf
Web service composition development is a complex and dynamic process. It is one of the challenges in distributed dynamic environments. Although, SOA (Service Oriented Architecture) facilitates service composition process through standard protocols in searching and binding with web services. Yet composition in SOA paradigm faces many challenges. One of the main challenges is the environment in which composition services are developed. Nowadays the environment becomes more dynamic due to the increase in the number of web services that are frequently changing. Therefore, the need for self-adapted composition methods that acts according to environment changes is advocated. In this paper, we will study the existe researches that address the web service composition in a dynamic environment to state the art in this area and assist future research.
JPJ1453 Web Service Recommendation via Exploiting Location and QoS Informationchennaijp
We are good IEEE java projects development center in Chennai and Pondicherry. We guided advanced java technologies projects of cloud computing, data mining, Secure Computing, Networking, Parallel & Distributed Systems, Mobile Computing and Service Computing (Web Service).
For More Details:
http://jpinfotech.org/final-year-ieee-projects/2014-ieee-projects/java-projects/
Impact 2008 1994A - Exposing services people want to consume: a model-driven ...Brian Petrini
Where did my SOA budget go? I just spent 80% of it on integration and I still haven't got an SOA! We used to call it Enterprise Application Integration (EAI), now we call it service exposition. EAI is still there, it's still hard, and it still takes the vast majority of implementation time on SOA projects. Most companies hadn't finished their EAI when SOA came along. This session discusses how to capture and model the true complexity of an integration interface, and how to relate that to product capabilities. We'll show new techniques for how models can be used to improve estimating, aid product selection, assist designers with common integration patterns, and ultimately generate artifacts. We will discuss common integration patterns such as re-tries, healthcheck, flow control, store-forward, event sequencing and note how these are typically achieved using the current product suite, with particular reference to products such as WebSphere Process Server and WebSphere ESB.
DEVNET-1153 Enterprise Application to Infrastructure Integration – SDN AppsCisco DevNet
We've all heard about SDN and how SDN provides flexible networks to solve networks operation challenges. With respect to SDN Applications, the most obvious conversation is about network applications and services. But today we will discuss how we at Cisco are addressing business challenges and impact business outcomes directly by connecting two disparate worlds of Enterprise applications (EA) and Networking stack using Cisco Integration Platform (CIP).
A Trajectory Calculus for Qualitative Spatial Reasoning Using Answer Set Prog...George Baryannis
Spatial information is often expressed using qualitative terms such as natural language expressions instead of coordinates; reasoning over such terms has several practical applications, such as bus routes planning. Representing and reasoning on trajectories is a specific case of qualitative spatial reasoning that focuses on moving objects and their paths. In this work, we propose two versions of a trajectory calculus based on the allowed properties over trajectories, where trajectories are defined as a sequence of non-overlapping regions of a partitioned map. More specifically, if a given trajectory is allowed to start and finish at the same region, 6 base relations are defined (TC-6). If a given trajectory should have different start and finish regions but cycles are allowed within, 10 base relations are defined (TC-10). Both versions of the calculus are implemented as ASP programs; we propose several different encodings, including a generalised program capable of encoding any qualitative calculus in ASP. All proposed encodings are experimentally evaluated using a real-world dataset. Experiment results show that the best performing implementation can scale up to an input of 250 trajectories for TC-6 and 150 trajectories for TC-10 for the problem of discovering a consistent configuration, a significant improvement compared to previous ASP implementations for similar qualitative spatial and temporal calculi.
Rule-based Real-Time Activity Recognition in a Smart Home EnvironmentGeorge Baryannis
This presentation outlines a rule-based approach for both offline and real-time recognition of Activities of Daily Living (ADL), leveraging events produced by a non-intrusive multi-modal sensor infrastructure deployed in a residential environment. Novel aspects of the approach include: the ability to recognise arbitrary scenarios of complex activities
using bottom-up multi-level reasoning, starting from sensor events at the lowest level; an effective heuristics-based method for distinguishing between actual and ghost images in video data; and a highly accurate indoor localisation approach that fuses different sources of location information. The proposed approach is implemented as a rule-based system
using Jess and is evaluated using data collected in a smart home environment. Experimental results show high levels of accuracy and performance,proving the effectiveness of the approach in real world setups.
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Quality assurance (QA) organizations can dramatically upgrade web services testing by applying continuous integration and continuous delivery/deployment (CI/CD) techniques derived from DevOps and by deploying software such as Jenkins, LISA, Maven, Cucumber and Gherkin.
Fluent Calculus-based Semantic Web Service Composition and Verification using...George Baryannis
We propose a composition and verification framework for Semantic Web Services specified using WSSL, a novel service specification language based on the fluent calculus, that addresses issues related to the frame, ramification and qualification problems. These deal with the succinct and flexible representation of non-effects, indirect effects and preconditions, respectively. The framework exploits the unique features of WSSL, allowing, among others, for: compositions that take into account ramifications of services; determining the feasibility of a composition a priori; and considering exogenous qualifications during the verification process. The framework is implemented using FLUX-based planning, supporting compositions with fundamental control constructs, including nondeterministic ones such as conditionals and loops. Performance is evaluated with regard to termination and execution time for increasingly complex synthetic compositions.
Location-Aware and Personalized Collaborative Filtering for Web Service Recom...1crore projects
IEEE PROJECTS 2015
1 crore projects is a leading Guide for ieee Projects and real time projects Works Provider.
It has been provided Lot of Guidance for Thousands of Students & made them more beneficial in all Technology Training.
Dot Net
DOTNET Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
Java Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
ECE IEEE Projects 2015
1. Matlab project
2. Ns2 project
3. Embedded project
4. Robotics project
Eligibility
Final Year students of
1. BSc (C.S)
2. BCA/B.E(C.S)
3. B.Tech IT
4. BE (C.S)
5. MSc (C.S)
6. MSc (IT)
7. MCA
8. MS (IT)
9. ME(ALL)
10. BE(ECE)(EEE)(E&I)
TECHNOLOGY USED AND FOR TRAINING IN
1. DOT NET
2. C sharp
3. ASP
4. VB
5. SQL SERVER
6. JAVA
7. J2EE
8. STRINGS
9. ORACLE
10. VB dotNET
11. EMBEDDED
12. MAT LAB
13. LAB VIEW
14. Multi Sim
CONTACT US
1 CRORE PROJECTS
Door No: 214/215,2nd Floor,
No. 172, Raahat Plaza, (Shopping Mall) ,Arcot Road, Vadapalani, Chennai,
Tamin Nadu, INDIA - 600 026
Email id: 1croreprojects@gmail.com
website:1croreprojects.com
Phone : +91 97518 00789 / +91 72999 51536
Location-Aware and Personalized Collaborative Filtering for Web Service Recom...1crore projects
IEEE PROJECTS 2015
1 crore projects is a leading Guide for ieee Projects and real time projects Works Provider.
It has been provided Lot of Guidance for Thousands of Students & made them more beneficial in all Technology Training.
Dot Net
DOTNET Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
Java Project Domain list 2015
1. IEEE based on datamining and knowledge engineering
2. IEEE based on mobile computing
3. IEEE based on networking
4. IEEE based on Image processing
5. IEEE based on Multimedia
6. IEEE based on Network security
7. IEEE based on parallel and distributed systems
ECE IEEE Projects 2015
1. Matlab project
2. Ns2 project
3. Embedded project
4. Robotics project
Eligibility
Final Year students of
1. BSc (C.S)
2. BCA/B.E(C.S)
3. B.Tech IT
4. BE (C.S)
5. MSc (C.S)
6. MSc (IT)
7. MCA
8. MS (IT)
9. ME(ALL)
10. BE(ECE)(EEE)(E&I)
TECHNOLOGY USED AND FOR TRAINING IN
1. DOT NET
2. C sharp
3. ASP
4. VB
5. SQL SERVER
6. JAVA
7. J2EE
8. STRINGS
9. ORACLE
10. VB dotNET
11. EMBEDDED
12. MAT LAB
13. LAB VIEW
14. Multi Sim
CONTACT US
1 CRORE PROJECTS
Door No: 214/215,2nd Floor,
No. 172, Raahat Plaza, (Shopping Mall) ,Arcot Road, Vadapalani, Chennai,
Tamin Nadu, INDIA - 600 026
Email id: 1croreprojects@gmail.com
website:1croreprojects.com
Phone : +91 97518 00789 / +91 72999 51536
WEB SERVICE COMPOSITION IN DYNAMIC ENVIRONMENT: A COMPARATIVE STUDYcscpconf
Web service composition development is a complex and dynamic process. It is one of the challenges in distributed dynamic environments. Although, SOA (Service Oriented Architecture) facilitates service composition process through standard protocols in searching and binding with web services. Yet composition in SOA paradigm faces many challenges. One of the main challenges is the environment in which composition services are developed. Nowadays the environment becomes more dynamic due to the increase in the number of web services that are frequently changing. Therefore, the need for self-adapted composition methods that acts according to environment changes is advocated. In this paper, we will study the existe researches that address the web service composition in a dynamic environment to state the art in this area and assist future research.
JPJ1453 Web Service Recommendation via Exploiting Location and QoS Informationchennaijp
We are good IEEE java projects development center in Chennai and Pondicherry. We guided advanced java technologies projects of cloud computing, data mining, Secure Computing, Networking, Parallel & Distributed Systems, Mobile Computing and Service Computing (Web Service).
For More Details:
http://jpinfotech.org/final-year-ieee-projects/2014-ieee-projects/java-projects/
Impact 2008 1994A - Exposing services people want to consume: a model-driven ...Brian Petrini
Where did my SOA budget go? I just spent 80% of it on integration and I still haven't got an SOA! We used to call it Enterprise Application Integration (EAI), now we call it service exposition. EAI is still there, it's still hard, and it still takes the vast majority of implementation time on SOA projects. Most companies hadn't finished their EAI when SOA came along. This session discusses how to capture and model the true complexity of an integration interface, and how to relate that to product capabilities. We'll show new techniques for how models can be used to improve estimating, aid product selection, assist designers with common integration patterns, and ultimately generate artifacts. We will discuss common integration patterns such as re-tries, healthcheck, flow control, store-forward, event sequencing and note how these are typically achieved using the current product suite, with particular reference to products such as WebSphere Process Server and WebSphere ESB.
DEVNET-1153 Enterprise Application to Infrastructure Integration – SDN AppsCisco DevNet
We've all heard about SDN and how SDN provides flexible networks to solve networks operation challenges. With respect to SDN Applications, the most obvious conversation is about network applications and services. But today we will discuss how we at Cisco are addressing business challenges and impact business outcomes directly by connecting two disparate worlds of Enterprise applications (EA) and Networking stack using Cisco Integration Platform (CIP).
A Trajectory Calculus for Qualitative Spatial Reasoning Using Answer Set Prog...George Baryannis
Spatial information is often expressed using qualitative terms such as natural language expressions instead of coordinates; reasoning over such terms has several practical applications, such as bus routes planning. Representing and reasoning on trajectories is a specific case of qualitative spatial reasoning that focuses on moving objects and their paths. In this work, we propose two versions of a trajectory calculus based on the allowed properties over trajectories, where trajectories are defined as a sequence of non-overlapping regions of a partitioned map. More specifically, if a given trajectory is allowed to start and finish at the same region, 6 base relations are defined (TC-6). If a given trajectory should have different start and finish regions but cycles are allowed within, 10 base relations are defined (TC-10). Both versions of the calculus are implemented as ASP programs; we propose several different encodings, including a generalised program capable of encoding any qualitative calculus in ASP. All proposed encodings are experimentally evaluated using a real-world dataset. Experiment results show that the best performing implementation can scale up to an input of 250 trajectories for TC-6 and 150 trajectories for TC-10 for the problem of discovering a consistent configuration, a significant improvement compared to previous ASP implementations for similar qualitative spatial and temporal calculi.
Rule-based Real-Time Activity Recognition in a Smart Home EnvironmentGeorge Baryannis
This presentation outlines a rule-based approach for both offline and real-time recognition of Activities of Daily Living (ADL), leveraging events produced by a non-intrusive multi-modal sensor infrastructure deployed in a residential environment. Novel aspects of the approach include: the ability to recognise arbitrary scenarios of complex activities
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Service-Oriented Architecture (SOA) has emerged as a prominent design style that enables an IT infrastructure to allow different applications to participate in business processes, regardless of their underlying features. In order to effectively discover and use the most suitable services, service description should provide a complete behavior model, describing the inputs and preconditions that are required before execution, as well as the outputs and effects of a successful execution. Such specifications are prone to a family of problems, known in the AI literature as the frame, ramification and qualification problems. These problems deal with the succinct and flexible representation of non-effects, indirect effects and preconditions, respectively. Research in services has largely ignored these problems, at the same time ignoring their effects, such as compromising the integrity and correctness of services and service compositions and the inability to provide justification for unexpected execution results.
To address these issues, this thesis proposes the Web Service Specification Language (WSSL), a novel, semantics-aware language for the specification and composition of services, independent of service design models. WSSL's foundation is the fluent calculus, a specification language for robots that offers solutions to the frame, ramification and qualification problems. Further language extensions achieve three major goals: realize service composition via planning, supporting non-deterministic constructs, such as conditionals and loops; include specification of QoS profiles; and support partially observable service states. Moreover, an innovative service composition and verification framework is implemented, that advances state-of-the-art by satisfying several desirable requirements simultaneously: ramifications and partial observability in service and goal modeling; non-determinism in composition schemas; dynamic binding of tasks to concrete services; explanations for unexpected behavior; QoS-awareness through pruning and ranking techniques based on heuristics and task-specific goals and an all-encompassing QoS aggregation method for global goals.
Experimental evaluation is performed using synthetically generated specifications and composition goals, investigating performance scalability in terms of execution time, as well as optimality with regard to the produced composite process. The results show that, even in the presence of ramifications in some specifications, functional planning is efficient for repositories up to 500 specifications. Also, the cost of functional discovery per single service is insignificant, hence achieving good performance even when executed for multiple candidate plans. Finally, optimality relies mainly on defining suitable problem-specific heuristics; thus, its success depends mostly on the expertise of the composition designer.
WSSL: A Fluent Calculus-based Language for Web Service SpecificationsGeorge Baryannis
In order to effectively discover and invoke a Web service, the provider must supply a complete specification of its behavior, with regard to its inputs and outputs, preconditions and effects. Devising such complete specifications comes with many issues that have not been adequately addressed by current service description efforts, such as WSDL, SAWSDL, OWL-S and WSMO. These issues involve the frame, ramification and qualification problems, which deal with the succinct and flexible representation of non-effects, indirect effects and preconditions, respectively. We propose WSSL, a novel specification language for services based on the fluent calculus, that is expressly designed to address the aforementioned issues. Also, a tool is implemented that translates WSSL specifications to FLUX programs and allows for service validation based on user-defined goals.
Lifecycle Management of Service-based Applications on Multi-Clouds: A Resear...George Baryannis
We identify current challenges in the deployment
of complex distributed applications on multiple Cloud
providers and review the state of the art in model-driven
Cloud software engineering. Challenges include lack of support
for heterogeneous Cloud providers; limited matchmaking
between application requirements and Cloud capabilities;
lack of meaningful cross-platform Cloud resource descriptions;
lack of lifecycle management of Cloud applications;
inadequate cross-layer monitoring and adaptation based
on event correlation; and others. In this paper we propose
solutions to these challenges and highlight the expected benefits
in the context of a complex distributed application.
We address the problem of synthesizing specifications for composite
Web services, starting from those of their component services.
Unlike related work in programming languages, we assume the
definition of the component services (i.e. their code) to be
unavailable --- at best, they are known by a specification which
(safely) approximates their functional behavior. Within this
scenario, we deduce general formula schemes to derive specifications
for basic constructs such as sequential, parallel compositions and
conditionals and provide details on how to handle the special cases of
loops and asynchronous execution. The resulting specifications facilitate
service verification and service evolution as well as auditing processes,
promoting trust between the involved partners.
Towards Realizing Dynamic QoS-aware Web Service Composition
1. Towards Realizing
Dynamic QoS-aware
Web Service Composition
PhD Symposium, ECOWS ‘10
George Baryannis
Supervisor: Dimitris Plexousakis
Computer Science Department Institute of Computer Science
University of Crete Foundation for Research &
Technology - Hellas
2. Outline
Introduction
• Research on Web Services
• Formal Specification of Web services and service compositions
• Automated Web Service Composition
Formal Web Service Specifications
• Addressing the Frame Problem
• The Ramification and Qualification Problems in Web Service
Specifications
• Automatic Derivation of Composite Specifications
Automated Web Service Composition
• Requirements for Automated Web Service Composition
• Classification and Comparison of Existing Approaches
• QoS-Awareness, Dynamicity and Scalability in AI Planning techniques
Research Plan & Conclusions
Towards Realizing Dynamic QoS-aware Web Service
George Baryannis 2
Composition
3. Research on Web Services
• The last decade has seen an exceptional wealth of research
on service-related topics
• European Union FP6 and FP7 funded projects and networks
• Research covers the full life-cycle of a Web service or a
Service-based Application:
– Service description − Service execution
– Service discovery − Service monitoring
– Service composition − Service adaptation
– Service deployment
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 3
4. Formal Specification of Web Services
• Complete formal specifications are crucial for both
– Service providers, to advertise more effectively the offered
services
– Service consumers, to make informed choices by knowing
the exact way in which a service is expected to perform
• Automatically processing specifications facilitates
faster service matchmaking and composition
– Provided that a right balance between formality and
tractability is achieved
• A series of issues need to be addressed
– The frame, ramification and qualification problems
– The problem of automatically deriving specifications for
service compositions
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 4
5. Automated Web Service Composition
• Service composition is the process of combining and
coordinating a set of services in order to achieve
functionality unachievable by any single service
• Many approaches that involve automation have been
proposed, with varying degrees of success
• We conducted an extensive comparative literature review
based on a series of requirements
– No approaches satisfy the complete spectrum of said
requirements
– AI Planning techniques seem to be more successful
• The following issues were identified
– Lack of dynamicity in existing AI Planning approaches
– Introducing QoS-awareness in AI Planning techniques
– Providing a detailed account of how scalability may be achieved
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 5
6. Outline
Introduction
• Research on Web Services
• Formal Specification of Web services and service compositions
• Automated Web Service Composition
Formal Web Service Specifications
• Addressing the Frame Problem
• The Ramification and Qualification Problems in Web Service
Specifications
• Automatic Derivation of Composite Specifications
Automated Web Service Composition
• Requirements for Automated Web Service Composition
• Classification and Comparison of Existing Approaches
• QoS-Awareness, Dynamicity and Scalability in AI Planning techniques
Research Plan & Conclusions
Towards Realizing Dynamic QoS-aware Web Service
George Baryannis 6
Composition
7. The Frame, Ramification and Qualification
Problems
• A common characteristic of major Web service
description frameworks, such as OWL-S and WSMO, is
the use of logic-based knowledge representation for
the description of service functionality (IOPEs)
• This makes them vulnerable to three well-known
problems
– The Frame Problem: how to state, in a concise way, that
nothing else changes, except when stated otherwise
– The Ramification Problem: how to represent and infer
information about the knock-on and indirect effects of an
action or an event
– The Qualification Problem: how to list all preconditions
that must be satisfied for an action to have a desired effect
and how to update them when new statements become
part of our knowledge
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 7
8. Addressing the Frame Problem
• The Frame Problem stems from explicitly stating which
predicates or functions each procedure (in our case,
service) does not change
– Instead, we can state which services change each predicate or
function
– Extend first-order predicate logic with:
• Special predicate Occur, of arity 1 and special variable α
• Occur(α) is true iff the service denoted by variable α has executed
successfully
• This solution was successfully applied to OWL-S service
descriptions
– An algorithm was implemented, to automatically transform
existing service descriptions accordingly
• No effort has been made to address the qualification and
ramification problems in the same context
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 8
9. The Ramification Problem
in Web Service Specifications (1)
• We want to create a specification for a money withdrawal service:
– The balance of the account should at least be equal to the amount of
money about to be withdrawn. Also, the credit card used for the
withdrawal must be valid.
– There is a daily limit for the amount of money an account holder can
withdraw in a day.
– A successful execution means that the new balance is equal to the old
one minus the amount of money withdrawn.
– Also, the total money withdrawn for the day should be increased by
the same amount.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 9
10. The Ramification Problem
in Web Service Specifications (2)
• As it has been shown in previous work, such a specification is incomplete
due to the frame problem
– A representation that handles the frame problem is shown below
• Suppose that a ramification of the increase in the total amount withdrawn
from the account due to the execution of the service is that if the daily
limit is surpassed, the credit card must be temporarily made invalid.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 10
11. The Ramification Problem
in Web Service Specifications (3)
• The lack of knowledge of an indirect effect may lead to the
assumption that a composition is valid and correct while that
particular effect may contradict a precondition of another
participating service
• The specification below precludes any indirect effects. How do we
include the previously mentioned ramification?
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 11
12. The Qualification Problem
in Web Service Specifications
• Suppose that we are told that there is an initial period after the
initial activation of a credit card when it cannot yet be used for
purchases (i.e. no money can be withdrawn) in other words a card
cannot be valid and at the same time be in a provisional state.
• How can this new knowledge, that may be expressed as
be assimilated in the existing specification? What new precondition
must be inferred? What if this leads to an inconsistent specification
(especially in the case of composite services)?
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 12
13. Automatic derivation
of composite specifications (1)
• No service description frameworks or service composition
approaches attempt to derive a complete specification of
the inputs, outputs, preconditions and effects (IOPEs) that
should be provided to a service consumer
– Such specifications promote and facilitate the reusability of
composite services
– They also allow for the detection of inconsistencies to decide
whether a set of services is composable
• The composite specification is directly linked to the
composition schema and the way the participating services
are orchestrated
– Which part of the participating services’ specifications should
be exposed?
• The full set of preconditions and effects of all participating services?
• Only the preconditions of the services whose inputs are exposed (and
the postconditions of the services whose outputs are exposed)?
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 13
14. Automatic derivation
of composite specifications (2)
• Let’s examine the following simple example:
InpI InpI
Service I InpA
Service A
OutA
PreI=true PostI=true PreA PostA
Service I Service A Service I
PreC=PreI=true PostC=PostI=true
Service C
??? ???
• The solution should be somewhere in the middle: find the minimal
subset of the participating services’ specifications that should form
the composite specification
– Insight on this matter can be given by programming language
specifications, weakest precondition and the Craig-Lyndon
interpolation theorem
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 14
15. Outline
Introduction
• Research on Web Services
• Formal Specification of Web services and service compositions
• Automated Web Service Composition
Formal Web Service Specifications
• Addressing the Frame Problem
• The Ramification and Qualification Problems in Web Service
Specifications
• Automatic Derivation of Composite Specifications
Automated Web Service Composition
• Requirements for Automated Web Service Composition
• Classification and Comparison of Existing Approaches
• QoS-Awareness, Dynamicity and Scalability in AI Planning techniques
Research Plan & Conclusions
Towards Realizing Dynamic QoS-aware Web Service
George Baryannis 15
Composition
16. Requirements for
Automated Web Service Composition (1)
1. Automation
– Minimize user intervention and accelerate the process
– Approaches should be at least partially automated
2. Dynamicity
– Produce an abstract composition schema with service placeholders
instead of actual services, which are only bound at run-time
– Dynamic schemas can be consistent and executable long after their
initial design
3. Semantic Capabilities
– Allow for more efficient service matchmaking
– Semantic descriptions should be exploited, if available
4. QoS-Awareness
– Composite services that not only provide the required functionality,
but also guarantee the best possible quality
5. Non-determinism
– Support for choice constructs (such as if-then-else) or loops (such as
repeat-while) George Baryannis 16
17. Requirements for
Automated Web Service Composition (2)
6. Partial observability
– Deal with incomplete (or even wrong) information about the initial
world state
7. Scalability
– Ensure acceptable performance even when the number of candidate
services or the complexity of the composition schema rise
8. Correctness
– Ensure that certain desired properties hold, such as the fact that a
certain set of outputs is guaranteed to be produced given a certain
set of inputs and conditions.
9. Domain independence
– The same approach should be applicable to different domains,
allowing for the solution of a broad range of problems
10. Adaptivity
– Adapt to any unexpected or desired changes in order to satisfy new
requirements or fit to new situations dictated by the environment
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 17
18. Classification of Composition Approaches
The classification is based on the way service
compositions are represented
1. Workflow-based approaches
– Use workflow languages such as BPEL or YAWL to exploit the
fact that a composite service is conceptually similar to a
workflow
2. Model-based approaches
– Employ modeling languages (Petri-nets, UML, FSMs) to
represent service compositions
3. Mathematics-based approaches
– Use logics, calculi or algebras to represent service
compositions
4. AI Planning
– Handle service composition as an AI planning problem
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 18
19. Comparison
• Automation, Semantic Capabilities, Correctness and Domain Independence have
been well researched, in general
• Non-determinism and Partial Observability have only been successfully handled in
more recent work in the ASTRO framework
• Adaptation is out of the scope of this particular survey
• Dynamicity, QoS Awareness and Scalability have not been adequately explored,
especially when it comes to service composition as AI planning
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 19
20. QoS-Awareness in AI Planning techniques
• QoS-Awareness has been largely ignored in approaches
that employ AI planning techniques
• Introducing QoS-Awareness involves at least 3
fundamental decisions:
1. Choose the AI planning technique that will be adapted to
be QoS-aware
2. Choose the QoS model that will be employed
3. Decide on which phases of the composition process to
include QoS characteristics
• QoS aspects can be used to speed up the plan generation by
pruning the search space (excluding services that don’t meet
QoS thresholds)
• QoS aspects can be included in the planning goals, although, at
first glance, this would complicate the goals and make them
harder to satisfy
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 20
21. Dynamicity in AI Planning techniques
• The vast majority of AI Planning approaches produce
static composition schemas
• Only Peer and Klusch include some form of dynamicity.
Peer’s approach supports generating new plans but
only at design time
• OWLS-XPLAN (Klusch et al.) and its replanning module
are a step in the right direction
– However, it offers no support for nondeterminism and
partial observability, QoS-awareness, scalability and any
proof of correctness
• It is challenging to explore how dynamicity at run-time
via replanning can be applied to planning techniques
that support most of these features, such as planning
as model checking
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 21
22. Scalability in Automated Web Service
Composition approaches
• While some of the approaches explicitly mention
scalability and provide details, the majority does
not provide a comprehensive examination of the
problem
– Any scalability claims should be supported by
experimental evaluation
• Achieving scalability involves identifying causes of
inefficiency and attempting to remove them
– This should be done only after evaluating the
significance of limiting the approach that way
– Trying to achieve scalability may sometimes lead to
crippling the overall applicability of the approach.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 22
23. Outline
Introduction
• Research on Web Services
• Formal Specification of Web services and service compositions
• Automated Web Service Composition
Formal Web Service Specifications
• Addressing the Frame Problem
• The Ramification and Qualification Problems in Web Service
Specifications
• Automatic Derivation of Composite Specifications
Automated Web Service Composition
• Requirements for Automated Web Service Composition
• Classification and Comparison of Existing Approaches
• QoS-Awareness, Dynamicity and Scalability in AI Planning techniques
Research Plan & Conclusions
Towards Realizing Dynamic QoS-aware Web Service
George Baryannis 23
Composition
24. Research Plan (1)
• We have identified two major goals for our research plan
• The first goal: define and formalize a novel specification
language for Web services and service compositions
– Taking into account the frame, ramification and qualification
problems, similarly to the way Kakas et al. provided Modular-E,
an action language that solves these problems by definition
– Providing support for the derivation of composite specifications
based on a composition schema
• Two initial milestones are identified
1. Explore the challenge of automatically deriving composite
specifications
2. Identify the cases where the frame, ramification and
qualification problems appear and examine the effects they
may have
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 24
25. Research Plan (2)
• The second goal: design and implement a dynamic,
QoS-aware automated service composition framework
– This framework will rely on the results of the first goal
• Services will be specified using the language produced in the first
goal
• The same language will be used to describe the resulting
composition
• A tentative roadmap for this goal is the following:
– Introduce QoS characteristics in the specification language
by exploring the work of Kritikos and Plexousakis on OWL-
Q
– Based on the literature review, select the most successful
planning technique (e.g. planning as model checking) and
attempt to introduce dynamicity by applying run-time
replanning methods.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 25
26. Conclusions
• Two major problems in the fields of service description and
composition were identified
– The inability of current service description and composition
frameworks to provide complete formal service specifications
– The lack of an effective Web service composition approach that
combines most desired requirements, such as QoS-awareness and
dynamicity
• Addressing these major issues is crucial for the realization of
primary principles of Service-Oriented Architecture such as service
reusability, discoverability and composability
• Realizing scalability, dynamicity and QoS-awareness in automated
Web service composition may prove to be the necessary incentive
for the wider adoption of automated techniques
– Of course, the eventual adoption of such approaches depends on the
availability of semantically-enabled services and effective discovery
techniques
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 26
29. Composition Models (1)
• Orchestration:
– a description of how the services that participate in a composition interact at the message
level, including the business logic and the order in which the interactions should be executed.
– An orchestration should define which message is sent when and by which participating
service.
• Choreography:
– associated with the globally visible message exchanges, rules of interaction and agreements
that occur between multiple business processes.
– Partners are in full control of their internal business processes and do not expose them to
other partners, unless they are essential to the communication
• Coordination:
– involves temporarily grouping a set of service instances following a coordination protocol. This
protocol dictates the way participating services interact and also the outcome of the
interaction, whether it was successful or not.
– All communication is done through a third party, called the coordinator, who ultimately is
responsible for the upholding of the protocol and the decision and dissemination of the
outcome, once the activity ends.
• Component Model:
– involves the actual linking between inputs and outputs when services are being composed
together.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 29
30. Composition Models (2)
• Orchestration vs. Composition Synthesis
– Composition synthesis concerns synthesizing a specification of how to
coordinate the component services to fulfill the client request, generating a
plan that dictates how to achieve a desired behavior by combining the
abilities of multiple services.
– Orchestration is about executing the result of composition synthesis by
coordinating the control and data flow among the participating services and
also about supervising and monitoring that execution.
• Orchestration vs. Choreography:
– Multi-party business process execution (in choreographies) vs. creation of a
business process executed by a single party (in orchestrations).
– In choreographies, the internal processes of partners are not exposed
– Although orchestration and choreography can be used separately to
implement a service composition, their different viewpoints can be combined
for a more complete representation.
– Orchestration can be used to describe participating services in the lower
abstraction level and choreography can give a higher level description of how
these orchestrations interact with each other and capture the complex
conversations between them in order to realize the goal set by the requester.
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 30
31. Workflow-based Service Composition:
The PAWS framework (Ardagna et al.)
Faulty services are replaced
Constraints usually by other candidate services
refer to QoS aspects and recovery actions are
and are expressed as SLAs enabled
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 31
Composition
32. Model-based Service Composition:
The SAM system (Brogi and Corfini)
• Web services are represented as CPR Nets, a Petri Net
variant
– OWLS2PNML translates OWL-S service descriptions to CPR
Nets described using Petri Net Markup Language (PNML)
• A two-step analysis is performed:
– Functional: the requester expresses the inputs and outputs of
the desired service and SAM attempts to incrementally
produce the outputs, starting from the inputs, resulting in a
minimal set of participating services
– Behavioral: if the request is purely functional, SAM attempts
to create a CPR Net that represents the behavior of the
composite service and checks if it is correct. If the request
contains a behavior represented as a CPR Net, the bisimilarity
of the two Petri Nets is checked.
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 32
Composition
33. Mathematics-based Service Composition:
The SPICE ACE engine (Lecue et al.)
• Requests are expressed in
a formal manner,
containing IOPEs, non-
functional properties,
related ontological
schemas and so on.
• The composite services
returned by the
Composition Factory are
ranked based on aggregate
non-functional property
values and/or semantic
similarity between the
requested and the
produced composite
service
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 33
Composition
34. Mathematics-based Service Composition:
The SPICE ACE engine (Lecue et al.)
• The authors exploit the fact that
OWL-S is based on Description Logics
and attempt to compute similarities
between such DL descriptions
• Similarities are expressed as causal
links (exact, plugin, subsumption,
intersection and disjoint, and a matrix
of all possible links is constructed
• The causal link matrix is extended
with non-functional properties
(CLM+)
• Using the CLM+ the output is
attempted to be achieved
incrementally starting from the input.
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 34
Composition
35. Service Composition as AI Planning
Messages Initial set
sent and of inputs
• Given: received
– S, the set of all possible world states, with s0 the initial state set of
Final
Available – G, the set of goal states we are attempting to reach outputs
service
operations – A, the set of all possible actions that can be performed
– Γ, a transition relation that describes the resulting state, when an
Internal
process action is executed at a given state
description
• Then AI planning (in the classical sense) is the problem of reaching
G, starting from s0 by executing actions ∈ A that lead to transitions
∈ Γ from one state ∈ S to another
• AI Planning techniques categorization
1. Classical Planning: state-space, or plan-space planning
2. Neoclassical Planning: graph-based planning, propositional
satisfiability and constraint satisfaction
3. Heuristics and Control Strategies: Partial Order Refinement,
Hierarchical Task Networks
4. Other planning techniques: abductive planning, planning based on
model checking
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 35
36. Service Composition as AI Planning:
OWLS-XPLAN (Klusch et al.)
OWL-S descriptions translated to PDDXML,
an XML variant of PDDL
The planner combines graph-
planning, to ensure that a plan
is always found, and HTN, to
take advantage of decompo-
sition
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 36
Composition
37. Service Composition as AI Planning:
The ASTRO project (Pistore et al.)
State transition systems describe all possible
behaviors of a BPEL process and support non- EaGLe is a formal language for the
determinism and partial observability
representation of planning goals
This formula represents all the
actions of the component services
as they are controlled by the
composite service
Towards Realizing Dynamic
QoS-aware Web Service George Baryannis 37
Composition
38. More on the ASTRO project (1)
BPEL-to-STS transformation
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 38
39. More on the ASTRO project (2)
Expressing requirements in EaGLe
Towards Realizing Dynamic QoS-aware Web Service Composition George Baryannis 39