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Distributed Transactional Memory (DTM) is a recent but promising model for programming distributed systems. It aims to present programmers with a simple to use distributed concurrency control abstraction (transactions), while maintaining performance and scalability similar to distributed fine-grained locks. Any complications usually associated with such(More)
Load balancing is one of the main challenges in a Virtual Machine (VM) Environment in order to ensure equal utilization of all the available resources while avoiding overloading a subset of machines. In this paper, we propose an efficient load balancing strategy based on VM live migration. Unlike previous work, our strategy records the history of mappings(More)
The first release of hardware transactional memory (HTM) as commodity processor posed the question of how to efficiently handle its best-effort nature. In this paper we present Part-HTM, the first hybrid transactional memory protocol that solves the problem of transactions aborted due to the resource limitations (space/time) of current best-effort HTM. The(More)
Pig muscle phosphoglucose isomerase modified with pyridoxal 5'-phosphate under conditions that cause at least 90% inactivation of its catalytic activity was found to incorporate about 1.5 eq of pyridoxal 5'-phosphate per subunit. After digestion with thermolysin, two pyridoxal 5'-phosphate-containing peptides were isolated and their amino acid sequences(More)
Glucose-6-phosphate isomerase (EC is a dimeric enzyme of molecular mass 132000 which catalyses the interconversion of D-glucose-6-phosphate and D-fructose-6-phosphate. The crystal structure of the enzyme from pig muscle has been determined at a nominal resolution of 2.6 A. The structure is of the alpha/beta type. Each subunit consists of two(More)
In this work we present OSARE, an active replication protocol for transactional systems that combines the usage of Optimistic Atomic Broadcast with a speculative concurrency control mechanism in order to overlap transaction processing and replica synchronization. OSARE biases the speculative serialization of transactions towards an order aligned with the(More)
Software Transactional Memories (STMs) are emerging as a potentially disruptive programming model. In this paper we are address the issue of how to enhance dependability of STM systems via replication. In particular we present AGGRO, an innovative Optimistic Atomic Broadcast-based (OAB) active replication protocol that aims at maximizing the overlap between(More)
Software Transactional Memories (STMs) are emerging as a highly attractive programming model, thanks to their ability to mask concurrency management issues to the overlying applications. In this paper we are interested in dependability of STM systems via replication. In particular we present an extensive simulation study aimed at assessing the efficiency of(More)
Nowadays the 2-Phase-Locking (2PL) concurrency control algorithm still plays a core rule in the construction of transactional systems (e.g. database systems and transactional memories). Hence, any technique allowing accurate analysis and prediction of the performance of 2PL based systems can be of wide interest and applicability. In this article we present(More)
We present an analytical performance modeling approach for concurrency control algorithms in the context of Software Transactional Memories (STMs). We consider a realistic execution pattern where each thread alternates the execution of transactional and non-transactional code portions. Our model captures dynamics related to the execution of both (i)(More)