The Peer-To-Peer (P2P) paradigm is a promising approach for several distributed applications, among which distributed storage systems. SPINA is a software architecture that aims at encompassing indexing and retrieval ...
详细信息
The Peer-To-Peer (P2P) paradigm is a promising approach for several distributed applications, among which distributed storage systems. SPINA is a software architecture that aims at encompassing indexing and retrieval of unstructured documents stored in a P2P network. This paper describes the current status of the design and the implementation of this software architecture.
Focus is on recovery of transactions in a distributed DB/DC system. The objective is to use transaction-level structural information to eliminate costly lower-level handshaking protocols, eliminate the need for any ce...
详细信息
ISBN:
(纸本)0818606908
Focus is on recovery of transactions in a distributed DB/DC system. The objective is to use transaction-level structural information to eliminate costly lower-level handshaking protocols, eliminate the need for any centralized recovery management mechanism by making recovery actions local to interacting components, and eliminate propagation of recovery actions to more than one antecedent or precedent component. Progressive recovery is a way of tracking the progress of a transaction to meet the above objective. Transaction processing involves different execution stages (DC, DB, followed by the DC), perhaps on different processors. Some stages make database changes and others are purely transformations of messages. The latter permit re-executions without side effects. The former must be well protected from re-executions. In contrast with optimistic recovery schemes, progressive recovery does not track communication and state dependencies.
Coordinated Atomic Actions (CAAs) have been introduced about ten years ago as a conceptual framework for developing fault-tolerant concurrent systems. All the work done since then extended the CAA framework with the c...
详细信息
ISBN:
(纸本)9780769530246
Coordinated Atomic Actions (CAAs) have been introduced about ten years ago as a conceptual framework for developing fault-tolerant concurrent systems. All the work done since then extended the CAA framework with the capabilities to model, verify, and implement concurrent distributedsystems.following pre-defined development methodologies. As a result, CAAs, compared to other approaches available, offer a rich set of means for engineering dependable systems. Nevertheless, it is sometimes difficult to have a global and analytical view of all the features available as this concept provides a number of features which need to be applied in combination. The main contribution of this paper is in presenting a complete state-of-the-art overview of the work done around CAAs from the three perspectives: the definitions of the fundamental concepts, their various semantics and the means supporting formal verification. This paper is useful for the potential CAAs users in helping them to avoid misinterpretation when employing all the available features. Finally, our paper should contribute in better understanding of the likely directions in which the CAA framework may evolve in the near future.
Very large scale distributedsystems.provide some of the most interesting research challenges while at the same time being increasingly required by nowadays applications. The escalation in the amount of connected devi...
详细信息
ISBN:
(纸本)9781479955848
Very large scale distributedsystems.provide some of the most interesting research challenges while at the same time being increasingly required by nowadays applications. The escalation in the amount of connected devices and data being produced and exchanged, demands new data management systems. Although new data stores are continuously being proposed, they are not suitable for very large scale environments. The high levels of churn and constant dynamics found in very large scale systems.demand robust, proactive and unstructured approaches to data management. In this paper we propose a novel data store solely based on epidemic (or gossip-based) protocols. It leverages the capacity of these protocols to provide data persistence guarantees even in highly dynamic, massive scale systems. We provide an open source prototype of the data store and correspondent evaluation.
software testing is a very expensive and time consuming process. It can account for up to 50% of the total cost of the software development. distributedsystems.make software testing a daunting task. The research desc...
详细信息
ISBN:
(纸本)0769526551
software testing is a very expensive and time consuming process. It can account for up to 50% of the total cost of the software development. distributedsystems.make software testing a daunting task. The research described in this paper investigates a novel multi-agent framework for testing 3-tier. distributedsystems. This paper describes the framework architecture as well as the communication mechanism among agents in the architecture. Web-based application is examined as a case study to validate the proposed framework. The framework is considered as a step forward to automate testing for distributedsystems.in order to enhance their reliability within an acceptable range of cost and time.
This conference proceedings contains 81 papers, with 7 papers in abstract form only. Discussed are: software tool, software engineering environment, databasesystems.with special attention to management and distribute...
详细信息
ISBN:
(纸本)0818605502
This conference proceedings contains 81 papers, with 7 papers in abstract form only. Discussed are: software tool, software engineering environment, databasesystems.with special attention to management and distributedsystems. concurrency control, quality through software engineering, distributed programming, high-level languages, various design techniques, life cycles, softwarereliability and reusability, national standards and standardization efforts, artificial intelligence applications including expert systems. verification and validation methods and other software applications on telecommunication systems. Operating systems. interfaces, data processing techniques, simulation models and algorithms and interactive programming are also considered.
Open distributed computer systems.are some of the most successful structures ever designed for the computer community together with their undisputed benefits for users. However, their complexity has also introduced a ...
详细信息
ISBN:
(纸本)0769526411
Open distributed computer systems.are some of the most successful structures ever designed for the computer community together with their undisputed benefits for users. However, their complexity has also introduced a few side-effects, most notably the unpredictable nature of the underlying environments and reconfiguration burdens imposed by environmental changes. Thus, to gain high level of system performance, a required level of reliability has to be maintained. In this paper, we propose a mechanism to analyze the underlying environmental faults and failures. This model provides an adaptable fault-tolerant approache in order to address unanticipated events and unpredictable hazards in distributedsystems. Therefore, this model maintains the required reliability by analyzing the environment and selects the optimal replication strategy for existing conditions. This pragmatic and theoretically appealing approach is a part of the Juice system which supports adaptation properties for open distributed environments.
Major efforts have been spent in recent years to improve the performance, scalability and reliability of distributedsystems. In order to hide the complexity of designing distributed applications, many proposals provi...
详细信息
ISBN:
(纸本)9781538683019
Major efforts have been spent in recent years to improve the performance, scalability and reliability of distributedsystems. In order to hide the complexity of designing distributed applications, many proposals provide efficient high-level communication abstractions (e.g., atomic multicast). These abstractions, however, are often unfamiliar to average application designers and, as a result, implementing distributed applications that tolerate failures and scale performance without sacrificing consistency remains a challenging task. In this paper, we introduce DMap, a reliable and scalable distributed ordered map. DMap fully implements the generic Java SortedMap interface and can be easily used to scale existing Java applications. To substantiate our claim, we have used DMap to turn H2, a centralized database, into a scalable and reliable data management system.
An engineering technology and formalized guidelines for automated development of system architectures are vital for assuring correctness, faultlessness, security, performance and reliability of enterprise IT systems. ...
详细信息
ISBN:
(纸本)1424402158
An engineering technology and formalized guidelines for automated development of system architectures are vital for assuring correctness, faultlessness, security, performance and reliability of enterprise IT systems. The described in this article approach leads to improved automation of development of correct architectural UML deployment and component diagrams for J2EE based hardware-softwaresystems.
distributed Hash Table (DHT) P2P systems.provide flexible management of large scale distributedsystems. They also provide efficient object localization given its key. However, they don't provide high level query ...
详细信息
ISBN:
(纸本)0769521681
distributed Hash Table (DHT) P2P systems.provide flexible management of large scale distributedsystems. They also provide efficient object localization given its key. However, they don't provide high level query languages to formulate such location queries. Recent efforts have been made to improve such querying capabilities. Nevertheless, most of the proposed solutions are based on special hashing functions or on an additional level of peers. This paper presents PinS, a P2P interrogation and indexation middle-ware for DHT based P2P systems. It improves data sharing in such systems.by supporting declarative queries and some facilities on data management without using particular hash functions or other requirements. Location queries may be conjunctions or disjunctions of conditions including comparison terms, and users may specify some evaluation constraints. Comprehensive or partial answers are provided. PinS supports pre-defined and customized attributes to describe objects and allows sharing objects with restricted access. Additionally PinS enables several query execution strategies and proposes the use of indexes to improve comparison queries support. Our performance analysis shows the scalability of the system. In particular, the complexity of the evaluation of conjunctive queries is independent of the number of objects registered in the system.
暂无评论