Análise de desempenho de sistemas distribuídos de grande porte na plataforma Java

The lava Platform is increasing1y being adopted in the development of distributed sys¬tems with higb user demando This kind of application is more complex because it needs beyond attending the functional requirements, to fulfil1 the pre-established performance parameters. This work makes a study on the Java Vutual Machine (JVM), approaching its intemal aspects and exploring the garbage collection strategies existing in the literature and used by the NM. It also presents a set of tools that helps in the job of optimizing applications and others that help in the monitoring of applications in the production envi¬ronment. Doe to the great amount of technologies that aim to solve problems which are common to the application layer, it becomes difficult to choose the one with best time response and less memory usage. This work presents a brief introduction to each one of tbe possible technologies and realize comparative tests through a statistical analysis of the response time and garbage collection activity random variables. The obtained results supply engineers and managers with a subside to decide which technologies to use in large applications through the knowledge of how they behave in their environments and the amount of resources that they consume. The relation between the productivity of the technology and its performance is also considered ao important factor in this choice

Desenvolvimento de um middleware para comunicação via web services e sua aplicação em sistemas de aquisição de dados industriais

The control of industrial processes has become increasingly complex due to variety of factory devices, quality requirement and market competition. Such complexity requires a large amount of data to be treated by the three levels of process control: field devices, control systems and management softwares. To use data effectively in each one of these levels is extremely important to industry. Many of today s industrial computer systems consist of distributed software systems written in a wide variety of programming languages and developed for specific platforms, so, even more companies apply a significant investment to maintain or even re-write their systems for different platforms. Furthermore, it is rare that a software system works in complete isolation. In industrial automation is common that, software had to interact with other systems on different machines and even written in different languages. Thus, interoperability is not just a long-term challenge, but also a current context requirement of industrial software production. This work aims to propose a middleware solution for communication over web service and presents an user case applying the solution developed to an integrated system for industrial data capture , allowing such data to be available simplified and platformindependent across the network

Lógica BDI fuzzy

Intendding to understand how the human mind operates, some philosophers and psycologists began to study about rationality. Theories were built from those studies and nowadays that interest have been extended to many other areas such as computing engineering and computing science, but with a minimal distinction at its goal: to understand the mind operational proccess and apply it on agents modelling to become possible the implementation (of softwares or hardwares) with the agent-oriented paradigm where agents are able to deliberate their own plans of actions. In computing science, the sub-area of multiagents systems has progressed using several works concerning artificial intelligence, computational logic, distributed systems, games theory and even philosophy and psycology. This present work hopes to show how it can be get a logical formalisation extention of a rational agents architecture model called BDI (based in a philosophic Bratman s Theory) in which agents are capable to deliberate actions from its beliefs, desires and intentions. The formalisation of this model is called BDI logic and it is a modal logic (in general it is a branching time logic) with three access relations: B, D and I. And here, it will show two possible extentions that tranform BDI logic in a modal-fuzzy logic where the formulae and the access relations can be evaluated by values from the interval [0,1]

Tvoice :um sistema de manipulação de linguagens para auxiliar portadores de necessidades especiais através da web

This work presents the tVoice, software that manipulates tags languages, extracting information and, being integral part of the VoiceProxy system, it aids bearers of special needs in the access to the Web. This system is responsible for the search and treatment of the documents in the Web, extracting the textual information contained in those documents and preceding the capability of generating eventually through translation techniques, an audio script, used by the of interface subsystem of VoiceProxy, the iVoice, in the process of voice synthesis. In this stage the tVoice, besides the treatment of the tag language HTML, processes other two formats of documents, PDF and XHTML. Additionally to allow that, besides the iVoice, other interface subsystems can make use of the tVoice through remote access, we propose distribution systems techniques based in the model Client-Server providers operations of the fashion of a proxy server treatment of documents

Production and body composition traits of broilers in relation to breast weight evaluated by path analysis

O peso do peito possui grande importância econômica na indústria de frangos, podendo estar associado a outras variáveis passíveis de seleção. Estimaram-se correlações fenotípicas entre características de desempenho (peso vivo aos 7, 28 dias e ao abate e profundidade de músculo peitoral por ultra-sonografia), carcaça (peso eviscerado e de pernas) e composição corporal (peso do coração, do fígado e da gordura abdominal), em uma linhagem de frangos, e quantificou-se a influência direta e indireta destas variáveis sobre o peso do peito. Para tanto, utilizou-se a análise de trilha, desdobrando-se a matriz de correlações parciais em coeficientes que forneceram a influência direta de uma variável sobre a outra, independentemente das demais. A manutenção das variáveis peso vivo ao abate e peso eviscerado na matriz de correlações pode ser prejudicial à análise estatística que envolve os sistemas de equações normais, como a análise de trilha, devido à multicolinearidade observada. O peso vivo ao abate e a profundidade do músculo peitoral por ultra-sonografia apresentaram efeitos diretos importantes sobre o peso de peito e foram identificadas como as principais responsáveis pela magnitude dos coeficientes de correlação obtidos. Assim, uma pré-seleção individual para estas características pode favorecer um aumento no peso de peito nesta linhagem, se mantidas as condições ambientais de criação dos frangos, uma vez que o peso vivo ao abate e a profundidade de músculo peitoral por ultra-sonografia afetam fenotipicamente e diretamente o peso de peito.

The Owner Share scheduler for a distributed system

In large distributed systems, where shared resources are owned by distinct entities, there is a need to reflect resource ownership in resource allocation. An appropriate resource management system should guarantee that resource's owners have access to a share of resources proportional to the share they provide. In order to achieve that some policies can be used for revoking access to resources currently used by other users. In this paper, a scheduling policy based in the concept of distributed ownership is introduced called Owner Share Enforcement Policy (OSEP). OSEP goal is to guarantee that owner do not have their jobs postponed for longer periods of time. We evaluate the results achieved with the application of this policy using metrics that describe policy violation, loss of capacity, policy cost and user satisfaction in environments with and without job checkpointing. We also evaluate and compare the OSEP policy with the Fair-Share policy, and from these results it is possible to capture the trade-offs from different ways to achieve fairness based on the user satisfaction. © 2009 IEEE.

Classificação e comparação de ferramentas para análise de desempenho de sistemas paralelos

Pós-graduação em Engenharia Elétrica - FEIS

Escalonamento de tarefas em sistemas distribuídos baseado no conceito de propriedade distribuída

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Why is it so difficult to identify a single indicator of water stress in plants? A proposal for a multivariate analysis to assess emergent properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de Desempenho de Aplicações Paralelas Utilizando MPI e PETSc

This work presents a study about the use of standards and directions on parallel programming in distributed systems, using the MPI standard and PETSc toolkit, performing an analysis of their performances over certain mathematic operations involving matrices. The concepts are used to develop applications to solve problems involving Principal Components Analysis (PCA), which are executed in a Beowulf cluster. The results are compared to the ones of an analogous application with sequencial execution, and then it is analized if there was any performance boost on the parallel application

Automatic Deployment of Applications in the Cloud

In distributed systems like clouds or service oriented frameworks, applications are typically assembled by deploying and connecting a large number of heterogeneous software components, spanning from fine-grained packages to coarse-grained complex services. The complexity of such systems requires a rich set of techniques and tools to support the automation of their deployment process. By relying on a formal model of components, a technique is devised for computing the sequence of actions allowing the deployment of a desired configuration. An efficient algorithm, working in polynomial time, is described and proven to be sound and complete. Finally, a prototype tool implementing the proposed algorithm has been developed. Experimental results support the adoption of this novel approach in real life scenarios.

Searching and retrieving in content-based repositories of formal mathematical knowledge

In this thesis, the author presents a query language for an RDF (Resource Description Framework) database and discusses its applications in the context of the HELM project (the Hypertextual Electronic Library of Mathematics). This language aims at meeting the main requirements coming from the RDF community. in particular it includes: a human readable textual syntax and a machine-processable XML (Extensible Markup Language) syntax both for queries and for query results, a rigorously exposed formal semantics, a graph-oriented RDF data access model capable of exploring an entire RDF graph (including both RDF Models and RDF Schemata), a full set of Boolean operators to compose the query constraints, fully customizable and highly structured query results having a 4-dimensional geometry, some constructions taken from ordinary programming languages that simplify the formulation of complex queries. The HELM project aims at integrating the modern tools for the automation of formal reasoning with the most recent electronic publishing technologies, in order create and maintain a hypertextual, distributed virtual library of formal mathematical knowledge. In the spirit of the Semantic Web, the documents of this library include RDF metadata describing their structure and content in a machine-understandable form. Using the author's query engine, HELM exploits this information to implement some functionalities allowing the interactive and automatic retrieval of documents on the basis of content-aware requests that take into account the mathematical nature of these documents.

Automated design of self-stabilization

Self-stabilization is a property of a distributed system such that, regardless of the legitimacy of its current state, the system behavior shall eventually reach a legitimate state and shall remain legitimate thereafter. The elegance of self-stabilization stems from the fact that it distinguishes distributed systems by a strong fault tolerance property against arbitrary state perturbations. The difficulty of designing and reasoning about self-stabilization has been witnessed by many researchers; most of the existing techniques for the verification and design of self-stabilization are either brute-force, or adopt manual approaches non-amenable to automation. In this dissertation, we first investigate the possibility of automatically designing self-stabilization through global state space exploration. In particular, we develop a set of heuristics for automating the addition of recovery actions to distributed protocols on various network topologies. Our heuristics equally exploit the computational power of a single workstation and the available parallelism on computer clusters. We obtain existing and new stabilizing solutions for classical protocols like maximal matching, ring coloring, mutual exclusion, leader election and agreement. Second, we consider a foundation for local reasoning about self-stabilization; i.e., study the global behavior of the distributed system by exploring the state space of just one of its components. It turns out that local reasoning about deadlocks and livelocks is possible for an interesting class of protocols whose proof of stabilization is otherwise complex. In particular, we provide necessary and sufficient conditions – verifiable in the local state space of every process – for global deadlock- and livelock-freedom of protocols on ring topologies. Local reasoning potentially circumvents two fundamental problems that complicate the automated design and verification of distributed protocols: (1) state explosion and (2) partial state information. Moreover, local proofs of convergence are independent of the number of processes in the network, thereby enabling our assertions about deadlocks and livelocks to apply on rings of arbitrary sizes without worrying about state explosion.

QoE-aware Multiple Path Video Transmission for Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) promise a wide scope of emerging potential applications in both civilian and military areas, which require visual and audio information to enhance the level of collected information. The transmission of multimedia content requires a minimal video quality level from the user’s perspective. However, links in WMSN communi- cations are typically unreliable, as they often experience fluctuations in quality and weak connectivity, and thus, the routing protocol must evaluate the routes by using end-to-end link quality information to increase the packet delivery ratio. Moreover, the use multiple paths together with key video metrics can enhance the video quality level. In this paper, we propose a video-aware multiple path hierarchical routing protocol for efficient multimedia transmission over WMSN, called video-aware MMtransmission. This protocol finds node-disjoint multiple paths, and implements an end-to-end link quality estimation with minimal over- head to score the paths. Thus, our protocol assures multimedia transmission with Quality of Experience (QoE) and energy-efficiency support. The simula- tion results show the benefits of video-aware MMtransmission for disseminating video content by means of energy-efficiency and QoE analysis.