CloudTPS: Scalable Transactions for Web Applications in the Cloud

CloudTPS: Scalable Transactions for Web Applications in the Cloud Technology Used: Dot Net NoSQL Cloud data stores provide scalability and high availability properties for web applications, but at the same time they sacrifice data consistency. However, many applications cannot afford any data inconsistency. CloudTPS is a scalable transaction manager which guarantees full ACID properties for multi-item transactions issued by Web applications, even in the presence of server failures and network partitions. We implement this approach on top of the two main families of scalable data layers: Bigtable and SimpleDB. Performance evaluation on…

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Dynamic Resource Allocation Using Virtual Machines for Cloud Computing Environment

Dynamic Resource Allocation Using Virtual Machines for Cloud Computing Environment Technology Used: Java Cloud computing allows business customers to scale up and down their resource usage based on needs. Many of the touted gains in the cloud model come from resource multiplexing through virtualization technology. In this paper, we present a system that uses virtualization technology to allocate data center resources dynamically based on application demands and support green computing by optimizing the number of servers in use. We introduce the concept of “skewness to measure the unevenness in the…

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Robust module-based data management

Robust module-based data management Technology Used: Java/J2EE The current trend for building an ontology-based data management system (DMS) is to capitalize on efforts made to design a preexisting well-established DMS (a reference system). The method amounts to extracting from the reference DMS a piece of schema relevant to the new application needs – a module –, possibly personalizing it with extra-constraints w.r.t. the application under construction, and then managing a dataset using the resulting schema. The existing definitions of modules is extended and novel properties of robustness that provide means…

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Toward trustworthy coordination of web services business activities

Toward trustworthy coordination of web services business activities To present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render the coordination of web services business activities (WS-BA) more trustworthy. The lightweight design of the BFT algorithm is the result of a comprehensive study of the threats to the WS-BA coordination services and a careful analysis of the state model of WS-BA. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant, state-machine replication of the WS-BA coordination…

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Real-time query scheduling for wireless sensor networks

Real-time query scheduling for wireless sensor networks Technology Implementation: JAVA Recent years have seen the emergence of wireless sensor network systems that must support high data rate and realtime queries of physical environments. This paper proposes Real-Time Query Scheduling (RTQS), a novel approach to conflict-free transmission scheduling for real-time queries in wireless sensor networks. First, we show that there is an inherent trade-off between prioritization and throughput in conflict-free query scheduling. We then present three new real-time scheduling algorithms. The non-preemptive query scheduling algorithm achieves high throughput while introducing priority…

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