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Distributed Computing Systems, 1993., Proceedings the 13th International Conference on

Date 25-28 May 1993

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  • Proceedings of IEEE International Conference on Distributed Computing Systems - ICDCS '93

    Publication Year: 1993
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    Freely Available from IEEE
  • Degradable agreement in the presence of Byzantine faults

    Publication Year: 1993 , Page(s): 237 - 244
    Cited by:  Papers (1)  |  Patents (1)
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    The authors consider a system consisting of a sender that wants to send a value to certain receivers. Byzantine agreement protocols have previously been proposed to achieve this in the presence of arbitrary failures. The imposed requirement typically is that the fault-free receivers must all agree on the same value. An agreement protocol is proposed that achieves Lamport's Byzantine agreement (L. Lamport et al., 1982) up to a certain number of faults and a degraded form of agreement with a higher number of faults. The degraded form of agreement allows the fault-free receivers to agree on at most two different values, one of which is necessarily the default value. The proposed approach is named degradable agreement. An algorithm for degradable agreement is presented along with bounds on the number of nodes and network connectivity necessary to achieve degradable agreement View full abstract»

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  • Approximate analysis of priority scheduling systems using stochastic reward nets

    Publication Year: 1993 , Page(s): 466 - 473
    Cited by:  Papers (4)
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    Presents a performance analysis of a heterogeneous multiprocessor system where tasks may arrive from Poisson sources as well as by spawning and probabilistic branching of other tasks. Non-preemptive priority scheduling is used between different tasks. Stochastic reward nets are used as the system model, and are solved analytically by generating the underlying continuous-time Markov chain. An approximation technique is used, that is based on fixed-point iteration to avoid the problem of a large underlying Markov chain. The iteration scheme works reasonably well, and the existence of a fixed point for the iterative scheme is guaranteed under certain conditions View full abstract»

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  • Deadline assignment in a distributed soft real-time system

    Publication Year: 1993 , Page(s): 428 - 437
    Cited by:  Papers (24)  |  Patents (2)
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    In a distributed environment, tasks often have processing demands on multiple sites. A distributed task is usually divided up into several subtasks, each one to be executed at some site in order. In a real-time system, an overall deadline is usually specified by an application designer indicating when a distributed task is to be finished. To study the subtask deadline assignment problem a simple model of the system and tasks is postulated. The focus is on soft real-time systems. In such systems, it is very difficult to guarantee that all deadlines will be met, and hence one tries to minimize the number of deadlines that are missed. The authors examine (through simulations) four strategies for subtask deadline assignment in a distributed soft real-time environment View full abstract»

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  • Intelligent job selection for distributed scheduling

    Publication Year: 1993 , Page(s): 517 - 524
    Cited by:  Papers (4)  |  Patents (2)
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    A key issue in distributed scheduling is selecting appropriate jobs to transfer. A job selection policy that considers the diversity of job behaviors is proposed. A mechanism used in artificial neural networks, called weight climbing, is employed. Using this mechanism, a distributed scheduler can learn the behavior of a job from its past executions and make a correct prediction about whether transferring the job is worthwhile. A scheduler using the proposed job selection policy has been implemented and experimental results show that it is able to learn job behaviors fast, make decisions accurately and adjust itself promptly when system configuration or program behaviors are changed. In addition, the selection policy introduces only negligible time and space overhead View full abstract»

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  • General structured voting: a flexible framework for modelling cooperations

    Publication Year: 1993 , Page(s): 227 - 236
    Cited by:  Papers (7)
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    Data replication schemes and mutual exclusion protocols can be regarded as special instances of cooperation schemes, which describe the interaction of independent nodes within a computer network to achieve a common goal. The author presents a new mechanism called general structured voting for cooperation management and demonstrates its use for handling instances of these problem domains. The proposed approach is shown to be very flexible, covers a wide range of scenarios, and supports an easy tailoring. In particular, it supports the switching from one cooperation scheme to another, e.g., as a reaction to changing network characteristics, simply by modifying the parameters of the model, avoiding a time and money consuming modification of the implementation View full abstract»

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  • Sharing complex objects in a distributed PEER environment

    Publication Year: 1993 , Page(s): 186 - 193
    Cited by:  Papers (1)  |  Patents (2)
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    For distributed computing environments, required for computer integrated manufacturing and other engineering applications, it is most important to support the sharing and exchange of complex objects among cooperating sites, while preserving their autonomy. Specification of complex objects and their object boundaries in a federated database are described. Each database, as well as the entire federation, is modeled as a collection of related objects. Complex objects are defined as subgraphs of the entire object base and are specified by a root object and a collection of paths. A complex object can be distributed over several sites. A method is described that ensures referential integrity while maintaining the autonomy of each database. Different linearization techniques of complex objects are supported to enable applications to retrieve complex objects as single entities. This model is implemented in PEER, a federated, object-oriented database system developed for engineering applications View full abstract»

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  • A general architecture for load balancing in a distributed-memory environment

    Publication Year: 1993 , Page(s): 47 - 54
    Cited by:  Papers (9)
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    The goal of load balancing is to assign to each node a number of tasks proportional to its performance. On distributed-memory machines, it is important to take data dependencies into account when distributing tasks, since they have a big impact on the communication requirements of the distributed application. The authors present a load balancing architecture that can deal with applications with heterogeneous tasks. The idea is to provide a set of load balancers that are effective for different types of homogeneous tasks, and to allow users to combine these load balancers for applications with heterogeneous tasks. This architecture was implemented on the Nectar multicomputer and performance results are presented for several applications with homogeneous and heterogeneous tasks View full abstract»

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  • A subsystem for swapping and mapped file I/O on top of Chorus

    Publication Year: 1993 , Page(s): 12 - 19
    Cited by:  Patents (5)
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    Chorus is a micro-kernel-based distributed operating system architecture. The authors explore the architectural and implementational issues involved in constructing a distributed paging service in the Chorus environment. Apart from outlining the pager architecture, they provide insight into how the characteristic goals of a critical distributed application on top of the Chorus system may be put into practice. The respective Chorus features are thereby judged in view of their suitability with respect to the pager implementation. The results of an experimental evaluation of the pager are included View full abstract»

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  • Deadlock prevention in the RTC programming system for distributed real-time applications

    Publication Year: 1993 , Page(s): 420 - 427
    Cited by:  Papers (2)
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    The RTC distributed real-time programming system was implemented using AND-OR locking of system resources to meet real-time and concurrency control requirements. Since RTC processes can hold locks while acquiring others, deadlock is possible and therefore a deadlock prevention technique was implemented for AND-OR locking in such systems. The authors briefly discuss the RTC programming system, illustrate the system's use in programming a timed version of the classic dining philosophers example, describe the deadlock prevention technique, and show how it is applied in the RTC dining philosophers example View full abstract»

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  • Uniform reliable multicast in a virtually synchronous environment

    Publication Year: 1993 , Page(s): 561 - 568
    Cited by:  Papers (22)
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    The authors present the definition of and solution to the uniform reliable multicast problem in the virtually synchronous environment defined by the Isis system. A uniform reliable multicast of a message m has the property that if m has been received by any destination process (faulty or not), then m is received by all processes that reach a decision. Uniform reliable multicast provides a solution to the distributed commit problem. Two multicast primitives are defined in the virtually synchronous model: reliable multicast (called view-atomic) and uniform reliable multicast (called uniform view-atomic). The view-atomic multicast is used to implement the uniform view-atomic primitive. As view-atomicity is based on the concept of process group membership, a connection is established between the process group membership and the distributed commit problems View full abstract»

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  • Distributed shared repository: a unified approach to distribution and persistency

    Publication Year: 1993 , Page(s): 20 - 29
    Cited by:  Papers (4)  |  Patents (1)
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    The authors propose an information management system providing distribution and persistency. By separating context from virtual address space, the system has a unified approach for both distribution and persistency. The former is achieved by moving contents between sites and the latter by moving contents between virtual address space and persistent storage. Contents include any information including data, program, and even the state of execution of a program. Contents are stored persistently in a logical space termed the distributed shared repository (DSR). A programming model for the DSR is proposed. Using the model, persistency, fine-grain mobility of information, and the passing of various distributed parameters can be obtained. The implementation anti experimental performance of the system are also presented View full abstract»

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  • Asynchronous event handling in distributed object-based systems

    Publication Year: 1993 , Page(s): 383 - 390
    Cited by:  Papers (1)  |  Patents (11)
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    Discusses the design and the operating system support necessary for providing asynchronous event handling in distributed, passive object-based programming environments, where objects are potentially shared by disparate applications. We discuss the necessity of thread-based as well as object-based event notification and how a variety of hard-to-solve distributed programming issues can be handled by using the approach outlined in the design. The usefulness of the design is considered by using some examples. The implementation strategy and related work in this area are discussed View full abstract»

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  • Run-time support and storage management for memory-mapped persistent objects

    Publication Year: 1993 , Page(s): 508 - 515
    Cited by:  Papers (1)  |  Patents (22)
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    The authors present the design and implementation of a persistent store called SPOMS. SPOMS is a runtime system that provides a store for persistent objects and is language independent. The objects are created via calls to SPOMS, and, when used, SPOMS directly maps them into the spaces of all requesting processes. The objects are stored in native format and are concurrently sharable. The store can handle distributed applications. The system uses the concept of a compiled class to manage persistent objects. The compiled class is a template that is used to create and store objects in a language independent manner and so that object reuse can occur without recompilation or relinking of an application that uses it. A prototype of SPOMS has been built on top of the Mach operating system. The motivations, the design, and implementation details are presented. Related and future work are discussed View full abstract»

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  • A performance study of general grid structures for replicated data

    Publication Year: 1993 , Page(s): 178 - 185
    Cited by:  Papers (10)
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    Recently, there has been considerable interest in the study of replica-control protocols which are based on organizing several copies of an object into logical structures, such as rectangular grids. In addition to high availability, another objective in exploiting such structures is to improve the degree of load sharing in a system. The authors extend the scope of grid structures to general grids, which allow holes in various positions of a rectangular structure and are useful to consider because they often produce availabilities that are higher than solid grids, where every position must be occupied by a node. In addition to proposing an improvement to the existing grid protocol, new insights are offered into the performance of the grids, from both availability and load sharing points of view. Algorithms for designing grids to maximize availability independently and also in conjunction with a load sharing constraint are given View full abstract»

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  • Laura: a coordination language for open distributed systems

    Publication Year: 1993 , Page(s): 39 - 46
    Cited by:  Papers (4)
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    Open distributed systems are an emerging class of distributed systems that have to take into account a number of heterogeneities in the system components and possibly high dynamics in the system structure by unrestrictedly joining and leaving agents. Uncoupled processing is a basis for a solution of the coordination problem that arises. Laura is a coordination language for open distributed systems following this paradigm by introducing a service space via which agents offer and request services without knowing about each other. They place and withdraw forms from the service space describing the type of service offered or requested. Type conformance based on subtyping determines if the forms match. An initial Laura implementation is described and further issues such as scalability and a role model are considered View full abstract»

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  • k-coteries for fault-tolerant k entries to a critical section

    Publication Year: 1993 , Page(s): 74 - 81
    Cited by:  Papers (12)
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    The authors extend the concept of coterie into k-coterie for k entries to a critical section. A structure named Cohorts is proposed to construct quorums in a k-coterie. The solution is resilient to node failures and/or network partitioning and has a low communication cost. The Cohorts structure is further improved to increase the availabilities of 1-entry critical sections View full abstract»

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  • Extraction of logical concurrency in distributed applications

    Publication Year: 1993 , Page(s): 66 - 73
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    Some methods are discussed to extract and represent the concurrency inherent in distributed applications. Concurrency is an application level property that is characterized completely by the set of messages exchanged in the application and the causal ordering relationship among the messages. The concurrency may be viewed at the logical level in the application rather than at the physical message communication level. The concurrency has a direct relationship to the message delivery performance in the underlying computation such as asynchronism in message delivery protocols. The authors quantitatively analyze how the application level concurrency influences the execution of the application. The analysis is based on methods for representing concurrency and deriving measures of concurrency from the representations. System level execution models based on ISIS, x-kernel and the causal broadcast communication system are used as case studies in the analysis. The analysis is in general useful in the design of applications and to compare their projected performance levels in an implementation-independent manner View full abstract»

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  • Diagnosis of single transition faults in communicating finite state machines

    Publication Year: 1993 , Page(s): 157 - 166
    Cited by:  Papers (3)
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    The authors propose a generalized diagnostic algorithm for the case where more than one fault (output or transfer) may be present in one of the transitions of a deterministic system represented by a set of communicating finite state machines (CFSMs). Such an algorithm localizes the faulty transition in the distributed system once the fault has been detected. It generates, if necessary, additional diagnostic test cases which depend on the observed symptoms and which permit the location of the detected faults. The algorithm guarantees the correct diagnosis of any single or double fault (output and/or transfer) in at most one of the transitions of a deterministic system which is represented by a set of communicating FSMs. A simple example is used to demonstrate the functioning of the different steps of the proposed diagnostic algorithm View full abstract»

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  • A state-aggregation method for analyzing dynamic load-balancing policies

    Publication Year: 1993 , Page(s): 482 - 489
    Cited by:  Papers (2)
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    Exact performance analyses of dynamic load-balancing policies for distributed systems are very difficult because the state space is multidimensional and load-balancing decisions are state-dependent. A state-aggregation method is proposed to analyze the performance of dynamic load-balancing policies. Those states with the same number of jobs are aggregated into a single state. The number of jobs in the system is modeled by a birth-death Markov process. The state transition rates are estimated by an iterative procedure. The proposed state-aggregation method is applied to analyze the performance of a particular dynamic load-balancing policy, namely a symmetric policy with threshold value equal to one. Extensive simulations were performed to study the accuracy of the state-aggregation method. This method provides accurate performance estimates for the symmetric policy for systems of various sizes when the mean job transfer delay is small compared to the average job service time View full abstract»

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  • Fast message ordering and membership using a logical token-passing ring

    Publication Year: 1993 , Page(s): 551 - 560
    Cited by:  Papers (33)  |  Patents (2)
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    The Totem protocol supports consistent concurrent operations by placing a total order on broadcast messages. This total order is achieved by including a sequence number in a token circulated around a logical ring that is imposed on a set of processors in a broadcast domain. A membership algorithm handles reconfiguration, including restarting of a failed processor and remerging of a partitioned network. Effective flow-control allows the protocol to achieve message ordering rates two to three times higher than the best prior protocols. The single-ring total ordering protocol of Totem provides fault-tolerant agreed and safe delivery of messages within a broadcast domain View full abstract»

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  • Disk cache replacement policies for network fileservers

    Publication Year: 1993 , Page(s): 2 - 11
    Cited by:  Papers (19)  |  Patents (9)
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    Trace driven simulations were used to study the performance of several disk cache replacement policies for network file servers. It is shown that locality based approaches, such as the common least recently used (LRU) policy, which are known to work well on stand-alone disked workstations and at client workstations in distributed systems, are inappropriate at a fileserver. Quite simple frequency based approaches do better. More sophisticated frequency based policies (eg., that take into account the file type) may offer additional improvements View full abstract»

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  • Average case behavior of election algorithms for unidirectional rings

    Publication Year: 1993 , Page(s): 366 - 373
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    The problem of election for asynchronous rings of processors is considered. Because of its many applications, this problem is important for both the practical and theoretical points of view. Thus, the availability of an algorithm that is good in both the average and the worst case has significant meaning. As an effort to achieve this goal, a new algorithm is designed and is simulated sequentially and analyzed by statistical methods. The statistical analysis demonstrates that the algorithm proposed is near optimal in the average case while its worst case message complexity is still O(n lg n). This is accomplished with the cost of one more bit in every message. This result is very interesting because it is contrary to the common belief that algorithms with good worst case complexity perform worse in the average case View full abstract»

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  • Distributed active catalogs and meta-data caching in descriptive name services

    Publication Year: 1993 , Page(s): 120 - 129
    Cited by:  Papers (5)  |  Patents (11)
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    Today's global internetworks challenge the ability of name services and other information services to locate data quickly. The authors introduce distributed active catalog and meta-data caching for optimizing queries in this environment. The active catalog constrains the search space for a query by returning a list of data repositories where the answer to the query is likely to be found. Meta-data caching improves performance by keeping frequently used characterizations of the search space close to the user, and eliminating active catalog communication and processing costs. When searching for query responses, the techniques contact only the small percentage of the data repositories with actual responses, resulting in search times of a few seconds. A distributed active catalog and meta-data caching method was implemented in a prototype descriptive name service called Nomenclator. Performance results for Nomenclator in a search space of 1000 data repositories are presented View full abstract»

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  • Delivering multicast messages in networks with mobile hosts

    Publication Year: 1993 , Page(s): 292 - 299
    Cited by:  Papers (32)  |  Patents (9)
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    There is a strong trend toward integrating portable computers within existing data networks. Traditional network protocols were designed assuming a static view of network connectivity. A mobile host can connect to the network from different locations at different times. This has led to the emergence of a new set of problems with regard to addressing schemes and network protocols for accommodating mobility within existing networks. The authors present a protocol for delivering a multicast message exactly once to a group of mobile destinations. The protocol is based on a system model derived from an architecture developed by J. Ioannidis et al. (1991), for mobile internetworking, relying on mobile support stations within the fixed network to communicate with mobile hosts View full abstract»

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