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Management of Replicated Data, 1992., Second Workshop on the

Date 12-13 Nov. 1992

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  • Second Workshop on the Management of Replicated Data (Cat. No.92TH0489-5)

    Publication Year: 1992
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    Freely Available from IEEE
  • Replication and mobility

    Publication Year: 1992, Page(s):9 - 12
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    Mobility of users and services and its impact on data replication and migration will be one of the main technical problems to be resolved. In fact, the authors view mobility as probably the most challenging new issue facing distributed systems of the future. The distinct new element which mobility brings into the issues of data replication is system's uncertainty about its own state (meaning prima... View full abstract»

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  • Weak consistency group communication for wide-area systems

    Publication Year: 1992, Page(s):13 - 16
    Cited by:  Papers (5)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    Replicated services can be implemented as process groups. Member processes use group communication protocols to communicate amongst themselves and group membership protocols to determine what processes are in the group. These protocols can provide various levels of consistency between members. The author investigates weak consistency protocols that guarantee that messages are delivered to all memb... View full abstract»

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  • The case for independent updates

    Publication Year: 1992, Page(s):17 - 19
    Cited by:  Papers (1)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    The authors present the case for allowing independent updates on replicated databases. In autonomous, heterogeneous, or large scale systems, using two-phase commit for updates may be infeasible. Instead, the authors propose that a site may perform updates independently. Sites that are available can receive these updates immediately. But sites that are unavailable, or otherwise do not participate i... View full abstract»

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  • Computing replica placement in distributed systems

    Publication Year: 1992, Page(s):58 - 61
    Cited by:  Papers (10)  |  Patents (36)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    The authors investigate the design of a replica management system (RMS) which allows a programmer to specify the quality of service required for individual replicated objects in terms of availability and performance. From the quality of service specification, information about the replication protocol to be used, and data about the characteristics of the underlying distributed system, the RMS comp... View full abstract»

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  • A replicated monitoring tool

    Publication Year: 1992, Page(s):96 - 99
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    Modeling the reliability of distributed systems requires a good understanding of the reliability of the components. Careful modeling allows highly fault-tolerant distributed applications to be constructed at the least cost. Realistic estimates can be found by measuring the performance of actual systems. An enormous amount of information about system performance can be acquired with no special priv... View full abstract»

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  • An analysis of replica control

    Publication Year: 1992, Page(s):22 - 25
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    Early replica control work focused on maintaining the availability of an object despite the unavailability of its copies. More recent work has focused on improving the response time, autonomy, and scalability of the earlier work while preserving their availability characteristics. The authors analyze the several ways the new algorithms make such improvements View full abstract»

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  • An algorithm for dynamic data distribution

    Publication Year: 1992, Page(s):62 - 65
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    The replication scheme of a distributed database determines how many replicas of each object are created, and to which processors these replicas are allocated. This scheme critically affects the performance of a distributed system, since reading an object locally is less costly than reading it from a remote processor. Therefore in a read-intensive network a widely distributed replication is mandat... View full abstract»

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  • Implementation and performance of cluster-based file replication in large-scale distributed systems

    Publication Year: 1992, Page(s):100 - 103
    Cited by:  Papers (1)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    The authors describe the implementation and an initial performance study of Frolic, a cluster-based dynamic file replication system. This system specifically targets large scale commercial environments with extensive file sharing, although it is expected to also perform well in systems with limited file sharing as well. Instead of keeping copies of a widely shared file at each client workstation, ... View full abstract»

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  • Dynamic logical structures: a position statement for managing replicated data

    Publication Year: 1992, Page(s):26 - 29
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    The authors discuss extensions to the grid protocol to improve the fault-tolerance of write operations by using the notions of structured read and write grid quorums. As is the case in the standard quorum protocols, the increased fault-tolerance for write operations is at the increased cost of executing read operations. In order to let users continue using the analogues of the read-one-write-all p... View full abstract»

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  • An integrated approach to fault tolerance

    Publication Year: 1992, Page(s):82 - 85
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    Describes Manetho, an experimental protocol system, whose goal is to explore the extent to which transparent fault tolerance can be added to long-running distributed applications. Transparent techniques are attractive because they can automatically add fault tolerance to existing applications that were written without consideration for reliability. Previous techniques for providing transparent fau... View full abstract»

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  • Replication in an information filtering system

    Publication Year: 1992, Page(s):66 - 67
    Cited by:  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    In the Tapestry system developed at Xerox PARC, users provide queries to filter incoming streams of documents. These queries run continuously over a growing database of electronic mail messages, news articles, and other textual documents. In the current implementation, all filter queries for all users run on a single database server. Those documents that match a user's filter query (or queries) ar... View full abstract»

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  • Efficient recovery in Harp [replicated Unix file system]

    Publication Year: 1992, Page(s):104 - 106
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    Harp is a replicated Unix file system accessible via the VFS interface. It provides highly available and reliable storage for files and guarantees that file operations are executed atomically in spite of concurrency and failures. Replication enables Harp to safely trade disk accesses for network communication and thus to provide good performance both during normal operation and during recovery. Th... View full abstract»

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  • Using volatile witnesses to extend the applicability of available copy protocols

    Publication Year: 1992, Page(s):30 - 33
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    This paper presents a new replication control protocol tailored to environments where network partitions can only occur at a few well-defined partition points and are always the results of a gateway failure. The protocol implements the same `write all read-one' rule as the available copy (AC) protocol. Unlike the AC protocol, this protocol divides servers holding copies into local servers that can... View full abstract»

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  • Primarily disconnected operation: experiences with Ficus

    Publication Year: 1992, Page(s):2 - 5
    Cited by:  Papers (24)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    Ficus is a flexible replication facility with optimistic concurrency control designed to span a wide range of scales and network environments. Support for partitioned operation is fundamental to the Ficus design but was not widely exercised in early Ficus use. This paper reports recent experiences using Ficus in settings where some replicas are only occasionally connected to a network, and hence p... View full abstract»

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  • Replicating the procedure call abstraction

    Publication Year: 1992, Page(s):86 - 89
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    The authors recommend replicating the procedure call abstraction as a method for constructing highly available distributed programs. In order to make highly available systems much more widespread than they are today, one must make it easier for application developers to incorporate replication into one's systems. Given that remote procedure call has proven to be a useful abstraction in building di... View full abstract»

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  • I/O performance of fully-replicated disk systems

    Publication Year: 1992, Page(s):68 - 71
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    Mirrored disk storage is an accepted technique to enhance fault-tolerance of data through complete replication. Recent research suggested that in addition to higher reliability, mirrored disks can offer better I/O performance by either allowing parallel reads or by reducing the seek time in cases where shortest seek distance algorithms can be used. Accurate analysis of mirrored disk systems shows ... View full abstract»

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  • Strong, weak and hybrid group membership

    Publication Year: 1992, Page(s):34 - 38
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    Discusses the group membership problem in distributed systems. The paper describes a set of group membership protocols that are developed as part of a toolkit for building distributed parallel applications on a cluster of workstations. The group membership service is the lowest layer in the toolkit, and it is the glue which unifies all the other layers. The group membership layer supports three pr... View full abstract»

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  • An interface to support lazy replicated file service

    Publication Year: 1992, Page(s):6 - 8
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    The authors argue that, if they are going to assume low-sharing workloads, then it is possible to build more efficient implementations that provide the same (or stronger) semantics by making fullest use of the assumption. Accordingly, they take an extreme point on the spreading/searching tradeoff: the searcher is made responsible for all the work. Thus, spreading can be made asynchronous and hence... View full abstract»

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  • Experiences with two high availability designs [replication techniques]

    Publication Year: 1992, Page(s):51 - 54
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    The author compares two replication schemes designed to provide high availability in an efficient manner: HA-NFS and ARM. Both schemes use the primary copy method for replica control. Both schemes were designed with the goal of minimizing the overheads during failure-free operation. In a primary copy scheme these overheads primarily consist of updating the secondary replicas. The two schemes were ... View full abstract»

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  • Some consequences of excess load on the Echo replicated file system

    Publication Year: 1992, Page(s):92 - 95
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    Understanding the workload is crucial for the success of a replicated file system. The system must continue to provide service in the presence of excess load, otherwise, its availability will be compromised. This paper presents some shortcomings of the Echo replicated file system in handling excess load. The authors discuss the consequences of excess load on primary secondary design, on their comm... View full abstract»

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  • Protocol modularity in systems for managing replicated data

    Publication Year: 1992, Page(s):78 - 81
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    The authors describe their experience in attempting to modularize Consul, a fault-tolerant system for managing replicated data. Their experience is that, while modularity is needed to simplify the design and implementation of such systems, protocol dependencies, both direct and indirect, impact the way in which protocols are designed and implemented. They also identify certain operating system fea... View full abstract»

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  • Highly-available services using the primary-backup approach

    Publication Year: 1992, Page(s):47 - 50
    Cited by:  Papers (37)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    The authors derive lower bounds and the corresponding optimal protocols for three parameters for synchronous primary-backup systems. They compare their results with similar results for active replication in order to determine whether the common folklore on the virtues of the two approaches can be shown formally. They also extend some of their results to asynchronous primary-backup systems. They im... View full abstract»

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  • An object-oriented approach for replication management

    Publication Year: 1992, Page(s):74 - 77
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    One important bottleneck in research on replication management is the time needed for implementing algorithms in order to validate them. The author's approach, based on the fragmented object model, encourages re-usability of distributed abstractions for many replication management algorithms. He presents high-level building blocks for various replication protocols, ensuring different policies of c... View full abstract»

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  • Bounds on the effects of replication on availability

    Publication Year: 1992, Page(s):44 - 46
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    The author discusses some theoretical limitations on the potential benefits of replication. In particular, he investigates two fundamental questions: (1) does placing copies of data around a network increase the probability that the data will be available, and (2) does such a technique decrease the mean duration of unavailability of the data. Given that many applications require mutually exclusive... View full abstract»

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