Renzo Davoli

Bio: Renzo Davoli is an academic researcher from University of Bologna. The author has contributed to research in topics: Virtual machine & Fault tolerance. The author has an hindex of 19, co-authored 57 publications receiving 1197 citations.

VDE: virtual distributed Ethernet

Abstract: The idea of VDE is very effective but straightforward simple and can be applied in very many configuration to provide several services. It is a sort of Swiss knife of emulated networks. It can be used as a general virtual private network as well as a support technology for mobility, a tool for network testing, a general reconfigurable overlay network, a layer for implementing privacy preserving technologies and many others. A prototype VDE has been implemented and released as free software under the GPL licence.

RELACS: A communications infrastructure for constructing reliable applications in large-scale distributed systems

Abstract: Distributed systems that span large geographic distances or manage large numbers of objects are already common place. In such systems, programming applications with even modest reliability requirements to run correctly and efficiently is a difficult task due to asynchrony and the possibility of complex failure scenarios. We describe the architecture of the RELACS communication subsystem that constitutes the microkernel of a layered approach to reliable computing in large-scale distributed systems. RELACS is designed to be highly portable and implements a very small number of abstractions and primitives that should be sufficient for building a variety of interesting higher-level paradigms. >

Group communication in partitionable systems: specification and algorithms

Abstract: Gives a formal specification and an implementation for a partitionable group communication service in asynchronous distributed systems. Our specification is motivated by the requirements for building "partition-aware" applications that can continue operating without blocking in multiple concurrent partitions and can reconfigure themselves dynamically when partitions merge. The specified service guarantees liveness and excludes trivial solutions, it constitutes a useful basis for building realistic partition-aware applications, and it is implementable in practical asynchronous distributed systems where certain stability conditions hold.

Paralex: an environment for parallel programming in distributed systems. Interim report

Abstract: Modern distributed systems consisting of powerful workstations and high-speed interconnection networks are an economical alternative to special-purpose super computers. The technical issues that need to be addressed in exploiting the parallelism inherent in a distributed system include heterogeneity, high-latency communication, fault tolerance and dynamic load balancing. Current software systems for parallel programming provide little or no automatic support towards these issues and require users to be experts in fault-tolerant distributed computing. The Paralex system is aimed at exploring the extent to which the parallel application programmer can be liberated from the complexities of distributed systems. Paralex is a complete programming environment and makes extensive use of graphics to define, edit, execute and debug parallel scientific applications. All of the necessary code for distributing the computation across a network and replicating it to achieve fault tolerance and dynamic load balancing is automatically generated by the system. In this paper we give an overview of Paralex and present our experiences with a prototype implementation.

Paralex: an environment for parallel programming in distributed systems

Abstract: Modern distributed systems consisting of powerful workstations and high-speed interconnection networks are an economical alternative to special-purpose super computers. The technical issues that need to be addressed in exploiting the parallelism inherent in a distributed system include heterogeneity, high-latency communication, fault tolerance and dynamic load balancing. Current software systems for parallel programming provide little or no automatic support towards these issues and require users to be experts in fault-tolerant distributed computing. The Paralex system is aimed at exploring the extent to which the parallel application programmer can be liberated from the complexities of distributed systems. Paralex is a complete programming environment and makes extensive use of graphics to define, edit, execute and debug parallel scientific applications. All of the necessary code for distributing the computation across a network and replicating it to achieve fault tolerance and dynamic load balancing is automatically generated by the system. In this paper we give an overview of Paralex and present our experiences with a prototype implementation.

Dryad: distributed data-parallel programs from sequential building blocks

Abstract: Dryad is a general-purpose distributed execution engine for coarse-grain data-parallel applications. A Dryad application combines computational "vertices" with communication "channels" to form a dataflow graph. Dryad runs the application by executing the vertices of this graph on a set of available computers, communicating as appropriate through flies, TCP pipes, and shared-memory FIFOs.The vertices provided by the application developer are quite simple and are usually written as sequential programs with no thread creation or locking. Concurrency arises from Dryad scheduling vertices to run simultaneously on multiple computers, or on multiple CPU cores within a computer. The application can discover the size and placement of data at run time, and modify the graph as the computation progresses to make efficient use of the available resources.Dryad is designed to scale from powerful multi-core single computers, through small clusters of computers, to data centers with thousands of computers. The Dryad execution engine handles all the difficult problems of creating a large distributed, concurrent application: scheduling the use of computers and their CPUs, recovering from communication or computer failures, and transporting data between vertices.

The process group approach to reliable distributed computing

Abstract: The difficulty of developing reliable distributed software is an impediment to applying distributed computing technology in many settings. Experience with the ISIS system suggests that a structured approach based on virtually synchronous process groups yields systems which are substantially easier to develop, fault-tolerance, and self-managing. Six years of research on ISIS are reviewed, describing the model, the types of applications to which ISIS was applied, and some of the reasoning that underlies a recent effort to redesign and reimplement ISIS as a much smaller, lightweight system.

[서평]「Computer Organization and Design, The Hardware/Software Interface」

Abstract: Recognizing the mannerism ways to get this books computer organization and design the hardware software interface 4th fourth edition by patterson hennessy is additionally useful. You have remained in right site to begin getting this info. acquire the computer organization and design the hardware software interface 4th fourth edition by patterson hennessy join that we manage to pay for here and check out the link.

Group communication specifications: a comprehensive study

Abstract: View-oriented group communication is an important and widely used building block for many distributed applications. Much current research has been dedicated to specifying the semantics and services of view-oriented group communication systems (GCSs). However, the guarantees of different GCSs are formulated using varying terminologies and modeling techniques, and the specifications vary in their rigor. This makes it difficult to analyze and compare the different systems. This survey provides a comprehensive set of clear and rigorous specifications, which may be combined to represent the guarantees of most existing GCSs. In the light of these specifications, over 30 published GCS specifications are surveyed. Thus, the specifications serve as a unifying framework for the classification, analysis, and comparison of group communication systems. The survey also discusses over a dozen different applications of group communication systems, shedding light on the usefulness of the presented specifications. This survey is aimed at both system builders and theoretical researchers. The specification framework presented in this article will help builders of group communication systems understand and specify their service semantics; the extensive survey will allow them to compare their service to others. Application builders will find a guide here to the services provided by a large variety of GCSs, which could help them choose the GCS appropriate for their needs. The formal framework may provide a basis for interesting theoretical work, for example, analyzing relative strengths of different properties and the costs of implementing them.

Extending Networking into the Virtualization Layer.

Abstract: The move to virtualization has created a new network access layer residing on hosts that connects the various VMs. Virtualized deployment environments impose requirements on networking for which traditional models are not well suited. They also provide advantages to the networking layer (such as software flexibility and welldefined end host events) that are not present in physical networks. To date, this new virtualization network layer has been largely built around standard Ethernet switching, but this technology neither satisfies these new requirements nor leverages the available advantages. We present Open vSwitch, a network switch specifically built for virtual environments. Open vSwitch differs from traditional approaches in that it exports an external interface for fine-grained control of configuration state and forwarding behavior. We describe how Open vSwitch can be used to tackle problems such as isolation in joint-tenant environments, mobility across subnets, and distributing configuration and visibility across hosts.