TIME: A Case Tool for developing Web-based Cooperative IS

Distributed web oriented processing environments have created the need for information sharing and transparent data access across heterogeneous information systems. This need stems from the proliferation of network based technologies that provide universal access to a growing number of information sources. Recently, new information system architectures including federated databases, cooperative information systems, and interoperable systems have been advocated in database research for the interoperation of multiple autonomous heterogeneous information systems over distributed networks

Checkpointing as a Service in Heterogeneous Cloud Environments

A non-invasive, cloud-agnostic approach is demonstrated for extending existing cloud platforms to include checkpoint-restart capability. Most cloud platforms currently rely on each application to provide its own fault tolerance. A uniform mechanism within the cloud itself serves two purposes: (a) direct support for long-running jobs, which would otherwise require a custom fault-tolerant mechanism for each application; and (b) the administrative capability to manage an over-subscribed cloud by temporarily swapping out jobs when higher priority jobs arrive. An advantage of this uniform approach is that it also supports parallel and distributed computations, over both TCP and InfiniBand, thus allowing traditional HPC applications to take advantage of an existing cloud infrastructure. Additionally, an integrated health-monitoring mechanism detects when long-running jobs either fail or incur exceptionally low performance, perhaps due to resource starvation, and proactively suspends the job. The cloud-agnostic feature is demonstrated by applying the implementation to two very different cloud platforms: Snooze and OpenStack. The use of a cloud-agnostic architecture also enables, for the first time, migration of applications from one cloud platform to another.Comment: 20 pages, 11 figures, appears in CCGrid, 201

Middleware-based Database Replication: The Gaps between Theory and Practice

The need for high availability and performance in data management systems has been fueling a long running interest in database replication from both academia and industry. However, academic groups often attack replication problems in isolation, overlooking the need for completeness in their solutions, while commercial teams take a holistic approach that often misses opportunities for fundamental innovation. This has created over time a gap between academic research and industrial practice. This paper aims to characterize the gap along three axes: performance, availability, and administration. We build on our own experience developing and deploying replication systems in commercial and academic settings, as well as on a large body of prior related work. We sift through representative examples from the last decade of open-source, academic, and commercial database replication systems and combine this material with case studies from real systems deployed at Fortune 500 customers. We propose two agendas, one for academic research and one for industrial R&D, which we believe can bridge the gap within 5-10 years. This way, we hope to both motivate and help researchers in making the theory and practice of middleware-based database replication more relevant to each other.Comment: 14 pages. Appears in Proc. ACM SIGMOD International Conference on Management of Data, Vancouver, Canada, June 200

MODELS AND SOLUTIONS FOR THE IMPLEMENTATION OF DISTRIBUTED SYSTEMS

Software applications may have different degrees of complexity depending on the problems they try to solve and can integrate very complex elements that bring together functionality that sometimes are competing or conflicting. We can take for example a mobile communications system. Functionalities of such a system are difficult to understand, and they add to the non-functional requirements such as the use in practice, performance, cost, durability and security. The transition from local computer networks to cover large networks that allow millions of machines around the world at speeds exceeding one gigabit per second allowed universal access to data and design of applications that require simultaneous use of computing power of several interconnected systems. The result of these technologies has enabled the evolution from centralized to distributed systems that connect a large number of computers. To enable the exploitation of the advantages of distributed systems one had developed software and communications tools that have enabled the implementation of distributed processing of complex solutions. The objective of this document is to present all the hardware, software and communication tools, closely related to the possibility of their application in integrated social and economic level as a result of globalization and the evolution of e-society. These objectives and national priorities are based on current needs and realities of Romanian society, while being consistent with the requirements of Romania's European orientation towards the knowledge society, strengthening the information society, the target goal representing the accomplishment of e-Romania, with its strategic e-government component. Achieving this objective repositions Romania and gives an advantage for sustainable growth, positive international image, rapid convergence in Europe, inclusion and strengthening areas of high competence, in line with Europe 2020, launched by the European Council in June 2010.information society, databases, distributed systems, e-society, implementation of distributed systems

Heterogeneous Relational Databases for a Grid-enabled Analysis Environment

Grid based systems require a database access mechanism that can provide seamless homogeneous access to the requested data through a virtual data access system, i.e. a system which can take care of tracking the data that is stored in geographically distributed heterogeneous databases. This system should provide an integrated view of the data that is stored in the different repositories by using a virtual data access mechanism, i.e. a mechanism which can hide the heterogeneity of the backend databases from the client applications. This paper focuses on accessing data stored in disparate relational databases through a web service interface, and exploits the features of a Data Warehouse and Data Marts. We present a middleware that enables applications to access data stored in geographically distributed relational databases without being aware of their physical locations and underlying schema. A web service interface is provided to enable applications to access this middleware in a language and platform independent way. A prototype implementation was created based on Clarens [4], Unity [7] and POOL [8]. This ability to access the data stored in the distributed relational databases transparently is likely to be a very powerful one for Grid users, especially the scientific community wishing to collate and analyze data distributed over the Grid