S* Service of category {send, email} with at least a fast response time

Market-awareness = MACOCO + Language to mitigate the obsolescence of the quality specifications - Consumers and providers are represented as active software agents who negotiate on their behalf. They have a common environment represented by the Blackboard. - Consumers avoid the obsolescence of their specifications by expressing their requirements using abstract specifications. These abstract specifications are concretized at runtime.

Market-­‐awareness  in  Service-­‐based  Systems  

Service providers and consumers exist in a  service market that is constantly changing. While service providers continuously improve their quality of services (QoS), service consumers can update their specifications according to what the market is offering. In this work, we propose a framework to enable online awareness of changes in the service market to both, consumers and providers, by representing them as active software agents. Our approach dictates that abstract specifications of the QoS are defined during design time. At runtime, consumer agents concretize QoS specifications according to the available market knowledge. Services agents are collectively aware of themselves and of the consumers’ requests. Moreover, these agents can create and maintain virtual organizations that create or maintain aligned the architecture of service-based systems with the market. 

Abstract  

Problem  

In  ac9on  

At runtime is valid only if K has not changed considerably since the specification S was defined

Related  Publica9ons  [1]- Requirements-Aware Systems A research agenda for RE for self-adaptive systems, Pete Sawyer, Nelly Bencomo, Jon Whittle, Emmanuel Letier, Anthony Finkelstein, International Requirements Engineering Conference, RE 2010, Sydney, Australia, September, 2010 [2]- Web service compositions which emerge from virtual organizations with fair agreements (best student paper), Romina Torres, Denise Rivera, Hernan Astudillo, KES Agent and Multi-Agent Systems. Technologies and Applications. Dubrovnik, Croatia, June 2012. [3]- Toward open-world software: Issue and challenges, Luciano Baresi, Elizabeth Di Nitto, and Carlo Ghezzi. Computer, vol. 39, no. 10, pp. 36–43, Oct. 2006.. [4]- Mitigating the obsolescence of quality-specification models in service-based systems, Romina Torres, Nelly Bencomo, Hernan Astudillo, in Model-Driven Requirements Engineering Workshop (MoDRE), sept. 2012. [5]- From virtual organizations to self-organizing web service compositions, Romina Torres, Denise Rivera, and Hernan Astudillo, in Proceedings of the XXIX International Conference of the Chilean Computer Science Society, ser. SCCC ’11. IEEE Computer Society, 2011. [6]- Four dark corners of requirements engineering, Pamela Zave and Michael Jackson ACM Trans. Softw. Eng. Methodol., vol. 6, no. 1, pp. 1–30, Jan. 1997.

Acknowledgements   This work was partially funded by FONDEF (grant D09i1171), UTFSM DGIP 241167, BASAL FB0821(FB.02PG.11), the EU Marie Curie Project Requirements@runtime and the EU Connect project.

Romina Torres, Hernan Astudillo Universidad Técnica Federico Santa María, Chile

{romina, hernan}@inf.utfsm.cl

Nelly Bencomo INRIA Paris - Rocquencourt, France

nelly@acm.org

Proposal

CONCLUSIONS  Service providers are collectively aware of the current demands of the market, other competitors and even potential partners to provide services as virtual organizations. Service consumers are continuously aware of the adaptations needed to automatically perform adaptive maintenance.

We propose to make service consumers and providers market-aware in order to achieve automatic adaptive maintenance of service-based systems.

KT

KT+v

KT+w

KT+x

KT+y

KT+z To maintain R satisfied:

…

KT+v

KT+z

Providers: -  are under an inherent competition with functionally-equivalent providers -  are passive entities waiting to be discovered -  are missing business opportunities

Consumers: -  QoS specifications depend on what the market is currently offering - Are too busy: trying to understand the market, searching candidates, composing solutions, verifying their compliance and determining the needed adaptations

with MACOCO

without MACOCO

R Send emails from the application as fast as possible

1

S Service of category 12100 with at least a response time less than 10 milliseconds

K What does it mean fast in services capable to send email?

,

23

At design time

R Send email with the location of user as fast as possible

S* Service of category {send, email} with at least a fast response time

L(KT) response time = {fast, average, slow} 2  

1

2+3  

3

At runtime

Contracts between consumers and providers are subscribed to the monitoring process of the adaptation recommender system (Adaptive). Time to time Adaptive monitors the contracts, analyze them (in order to determine if the contracts have been violated recurrently) and ask to the market a new configuration if an adaptation is needed. The service market is also monitored. If there is enough evidence the market has changed, then a new knowledge domain is generated and then all contracts are remapped into concrete specifications.

4periodically