Fábio N de Souza | Universidade Federal de Pernambuco (original) (raw)

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Papers by Fábio N de Souza

2013 21st Euromicro International Conference on Parallel, Distributed, and Network-Based Processing, 2013

2015 IEEE International Conference on Services Computing, 2015

Quality attributes play a very relevant role in the service-oriented computing world, as they all... more Quality attributes play a very relevant role in the service-oriented computing world, as they allow distinguishing between functionally equivalent services. In fact, these attributes impact various activities related to the life-cycle of service-based applications (SBAs), starting from service discovery and permeating other activities such as service level agreement establishment and monitoring. Considering their relevance, it is essential that these attributes are precisely defined. Moreover, as quality attributes are inherently dynamic, they must be continuously monitored. In this context, this paper proposes a meta-model that formally defines and connects service, quality and event domains. From one perspective, the connection between service and quality domains enables the design of models that formally specify applications' functional and non-functional requirements. From another perspective, connections between quality and event domains enable quality engineers to define how relevant quality attributes and metrics can be computed based on a set of runtime events. Conformant models can be interpreted at runtime by compatible platforms allowing them to dynamically (re)configure their monitoring mechanisms.

2014 IEEE International Conference on Services Computing, 2014

ABSTRACT Service oriented computing enables the development of applications as compositions of ba... more ABSTRACT Service oriented computing enables the development of applications as compositions of basic entities called services. These services offer business functions, which are used as primary criteria in the service selection algorithms. In distributed scenarios, a large number of services can offer similar functionalities, motivating the embracement of quality attributes as fundamental selection elements. Different strategies can be used to classify services based on these attributes and it is quite difficult to elect one that seems adequate in every scenario. In this context, we present DSOA platform, which is an environment that supports dynamic service compositions based on quality attributes. Particularly, our focus in this paper is in its Service Selection component which supports the definition of new selection strategies at runtime. In order to validate our solution, we perform an experimental evaluation that shows the utilization of different service selection strategies and their performance impacts and effectiveness in selecting services.

2008 IEEE International Performance, Computing and Communications Conference, 2008

The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of num... more The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of numerous parameters at different layers that include the database management system, network, operating system, Java Virtual Machine, JEE application server and application code level itself. At the application server level, an important element to be considered is the instance pooling mechanism, which manages the creation of instances required to process client requests. This paper proposes Petri net models to represent the instance pooling mechanism embedded in the JBoss application server and demonstrates how those models can be used for performance evaluation.

The need to replacing services belonging to a composition is motivated by several reasons, such ... more The need to replacing services belonging to a composition is motivated by several reasons, such as changes in the application’s requirements, bug fixing, existence of a fresh service and so on. Due to the large number of services having similar (or even identical) functionalities, it has been widely accepted that the selection process for a new service should also take into account non-functional requirements (QoS attributes), such as performance, availability, security and so on. Existing approaches for service selection are usually static and do not consider quality attributes, i.e., they adopt a strategy (ranking algorithm) to rank the candidate services that is usually based on functional aspects and is never altered. In this context, this paper proposes a solution that’s able to change the ranking strategy at runtime based on historical data of quality attributes. In order to validate the proposed solution, we perform an experimental evaluation that shows its performance impact and effectiveness in on service selection.

Service oriented computing enables the development of applications as compositions of basic entit... more Service oriented computing enables the development of applications as compositions of basic entities called services. These services offer business functions, which are used as primary criteria in the service selection algorithms. In distributed scenarios, a large number of services can offer similar functionalities, motivating the embracement of quality attributes as fundamental selection elements. Different strategies can be used to classify services based on these attributes and it is quite difficult to elect one that seems adequate in every scenario. In this context, we present DSOA platform, which is an environment that supports dynamic service compositions based on quality attributes. Particularly, our focus in this paper is in its Service
Selection component which supports the definition of new selection strategies at runtime. In order to validate our solution, we perform an experimental evaluation that shows the utilization of different service selection strategies and their performance impacts and effectiveness in selecting services.

Abstract—Quality attributes play a very relevant role in the service-oriented computing world, as... more Abstract—Quality attributes play a very relevant role in the
service-oriented computing world, as they allow distinguishing
between functionally equivalent services. In fact, these attributes have an impact in various activities related to the life-cycle of service-based applications (SBAs), starting from service discovery and permeating other activities such as service level agreement establishment and monitoring. Considering their relevance, it is essential that these attributes are precisely defined. Moreover, as quality attributes are inherently dynamic, they must be continuously monitored. In this context, this paper proposes a meta-model that formally defines and connects service, quality and event domains. From one perspective, the connection between service and quality domains enables the design of models that formally specify applications’ functional and non-functional requirements. From another perspective, connections between quality and event domains enable quality engineers to define how relevant quality attributes and metrics can be computed based on a set of runtime events. Finally, conformant models can be interpreted at runtime by compatible platforms allowing them to dynamically (re)configure their monitoring mechanisms.

The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of num... more The capacity management of a Java Enterprise Edition
(JEE) application involves the tuning of numerous
parameters at different layers that include the database
management system, network, operating system, Java
Virtual Machine, JEE application server and application
code level itself. At the application server level, an
important element to be considered is the instance pooling
mechanism, which manages the creation of instances
required to process client requests. This paper proposes
Petri net models to represent the instance pooling
mechanism embedded in the JBoss application server and
demonstrates how those models can be used for
performance evaluation.

2013 21st Euromicro International Conference on Parallel, Distributed, and Network-Based Processing, 2013

2015 IEEE International Conference on Services Computing, 2015

Quality attributes play a very relevant role in the service-oriented computing world, as they all... more Quality attributes play a very relevant role in the service-oriented computing world, as they allow distinguishing between functionally equivalent services. In fact, these attributes impact various activities related to the life-cycle of service-based applications (SBAs), starting from service discovery and permeating other activities such as service level agreement establishment and monitoring. Considering their relevance, it is essential that these attributes are precisely defined. Moreover, as quality attributes are inherently dynamic, they must be continuously monitored. In this context, this paper proposes a meta-model that formally defines and connects service, quality and event domains. From one perspective, the connection between service and quality domains enables the design of models that formally specify applications' functional and non-functional requirements. From another perspective, connections between quality and event domains enable quality engineers to define how relevant quality attributes and metrics can be computed based on a set of runtime events. Conformant models can be interpreted at runtime by compatible platforms allowing them to dynamically (re)configure their monitoring mechanisms.

2014 IEEE International Conference on Services Computing, 2014

ABSTRACT Service oriented computing enables the development of applications as compositions of ba... more ABSTRACT Service oriented computing enables the development of applications as compositions of basic entities called services. These services offer business functions, which are used as primary criteria in the service selection algorithms. In distributed scenarios, a large number of services can offer similar functionalities, motivating the embracement of quality attributes as fundamental selection elements. Different strategies can be used to classify services based on these attributes and it is quite difficult to elect one that seems adequate in every scenario. In this context, we present DSOA platform, which is an environment that supports dynamic service compositions based on quality attributes. Particularly, our focus in this paper is in its Service Selection component which supports the definition of new selection strategies at runtime. In order to validate our solution, we perform an experimental evaluation that shows the utilization of different service selection strategies and their performance impacts and effectiveness in selecting services.

2008 IEEE International Performance, Computing and Communications Conference, 2008

The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of num... more The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of numerous parameters at different layers that include the database management system, network, operating system, Java Virtual Machine, JEE application server and application code level itself. At the application server level, an important element to be considered is the instance pooling mechanism, which manages the creation of instances required to process client requests. This paper proposes Petri net models to represent the instance pooling mechanism embedded in the JBoss application server and demonstrates how those models can be used for performance evaluation.

The need to replacing services belonging to a composition is motivated by several reasons, such ... more The need to replacing services belonging to a composition is motivated by several reasons, such as changes in the application’s requirements, bug fixing, existence of a fresh service and so on. Due to the large number of services having similar (or even identical) functionalities, it has been widely accepted that the selection process for a new service should also take into account non-functional requirements (QoS attributes), such as performance, availability, security and so on. Existing approaches for service selection are usually static and do not consider quality attributes, i.e., they adopt a strategy (ranking algorithm) to rank the candidate services that is usually based on functional aspects and is never altered. In this context, this paper proposes a solution that’s able to change the ranking strategy at runtime based on historical data of quality attributes. In order to validate the proposed solution, we perform an experimental evaluation that shows its performance impact and effectiveness in on service selection.

Service oriented computing enables the development of applications as compositions of basic entit... more Service oriented computing enables the development of applications as compositions of basic entities called services. These services offer business functions, which are used as primary criteria in the service selection algorithms. In distributed scenarios, a large number of services can offer similar functionalities, motivating the embracement of quality attributes as fundamental selection elements. Different strategies can be used to classify services based on these attributes and it is quite difficult to elect one that seems adequate in every scenario. In this context, we present DSOA platform, which is an environment that supports dynamic service compositions based on quality attributes. Particularly, our focus in this paper is in its Service
Selection component which supports the definition of new selection strategies at runtime. In order to validate our solution, we perform an experimental evaluation that shows the utilization of different service selection strategies and their performance impacts and effectiveness in selecting services.

Abstract—Quality attributes play a very relevant role in the service-oriented computing world, as... more Abstract—Quality attributes play a very relevant role in the
service-oriented computing world, as they allow distinguishing
between functionally equivalent services. In fact, these attributes have an impact in various activities related to the life-cycle of service-based applications (SBAs), starting from service discovery and permeating other activities such as service level agreement establishment and monitoring. Considering their relevance, it is essential that these attributes are precisely defined. Moreover, as quality attributes are inherently dynamic, they must be continuously monitored. In this context, this paper proposes a meta-model that formally defines and connects service, quality and event domains. From one perspective, the connection between service and quality domains enables the design of models that formally specify applications’ functional and non-functional requirements. From another perspective, connections between quality and event domains enable quality engineers to define how relevant quality attributes and metrics can be computed based on a set of runtime events. Finally, conformant models can be interpreted at runtime by compatible platforms allowing them to dynamically (re)configure their monitoring mechanisms.

The capacity management of a Java Enterprise Edition (JEE) application involves the tuning of num... more The capacity management of a Java Enterprise Edition
(JEE) application involves the tuning of numerous
parameters at different layers that include the database
management system, network, operating system, Java
Virtual Machine, JEE application server and application
code level itself. At the application server level, an
important element to be considered is the instance pooling
mechanism, which manages the creation of instances
required to process client requests. This paper proposes
Petri net models to represent the instance pooling
mechanism embedded in the JBoss application server and
demonstrates how those models can be used for
performance evaluation.