PODC

This paper describes programming constructs and system support functions that are intended to facilitate the programming of reliable distributed systems. The systems considered include very different kinds of computers communicating through a network. ...

Design and implementation of an inter-address-space communication mechanism for the SBN network computer are described. SBN's basic communication primitives appear in context of a new distributed systems programming language strongly supported by the ...

A large array is an array whose storage is distributed among primary and secondary storage and whose processing may be distributed among several tasks in a distributed system. This paper presents a semantic model (set of language concepts) for ...

This paper describes a new model for dynamic distributed systems, where new processes are added and terminated at execution time. It is an extension of the static model underlying CSP. The model uses CSP I/O commands as the basic means of communications ...

The use of UIDs as internal names in an operating system for a local network is discussed. The use of internal names in other distributed systems is briefly surveyed. For this system, UIDs were chosen because of their intrinsic location independence and ...

Complex systems (such as distributed ones) should be specified before they are implemented. Even more advantages accrue if the specifications are executable, so that behaviors of the specified systems can be tested. This paper addresses practical ...

In computer networks, message routing is often accomplished by network nodes using local information. The unavailability of global information intuitively makes hard routing problems virtually impossible. This paper formalizes this intuition by ...

A fundamental problem in the theory of parallel computation is to find an efficient interconnection pattern between N processors that minimizes the number of lines entering or leaving each processor while enabling fast communication between the ...

Using a simple finite degree interconnection network among n processors and a straightforward randomized algorithm for packet delivery, it is possible to deliver a set of n packets travelling to unique targets from unique sources in 0(log n) expected ...

Distributed systems make possible both a high degree of concurrency and robustness in the face of failure. One approach to achieving these goals is to employ pools of servers implementing major system functions. This paper describes the concept of pools ...

In this paper we consider a resource allocation problem which is local in the sense that the maximum number of users competing for a particular resource at any time instant is bounded and also at any time instant the maximum number of resources that a ...

This paper addresses the problem of finding safe paths through a network, some of whose nodes may be faulty. By a safe path we mean one between two nodes that does not contain any faulty node. The kinds of faults that concern us are not limited to those ...

An algebraic calculus of asynchronous parallel computation, called CCS (Calculus of Communicating Systems), was developed in [HM,Mil 1]. CCS can express both the semantics of parallel programming languages and the behaviour of data structures (mailbox, ...

Systems of processes connected together by communication channels are studied semantically. A model for such systems, based on traces of communication events, is described. This semantic model is more general than the stream function model described by ...

Given an n-nodes network and an assertion G expressing its correctness, it is shown that G can be decomposed into collection of n local assertions and n.(n-1) “communication” assertions. The special case of a 2-nodes network is first examined, and it is ...

Byzantine Agreement has become increasingly important in establishing distributed properties when there may exist errors in the systems. Recent polynomial algorithms for reaching Byzantine Agreement provide us with feasible solutions for obtaining ...

Message passing provides a way for concurrently executing processes to communicate and synchronize. In this paper, we develop proof rules for asynchronous message-passing primitives (i.e. “send no-wait”). Two benefits accrue from this. The obvious one ...

Exchange of information between executing processes is one of the primary reasons for process interaction. Many distributed systems implement explicit message passing primitives to facilitate intercommunication. Typically, a process executes a write ...

This paper presents a distributed algorithm to detect deadlocks in distributed data bases. Features of this paper are (1) a formal model of the problem is presented, (2) the correctness of the algorithm is proved, i.e. we show that all true deadlocks ...

This paper reexamines deadlock prevention in the context of multiprocessor or distributed systems. The essential idea is to have a deadlock prevention process that executes “on-the-fly”, i.e. in parallel with processes that use resources. The prevention ...

Two locking protocols are defined for distributed database systems. One protocol provides deadlock avoidance without the need to roll back transactions. The other allows a useful weakening of the protocol in which only a limited class of easily handled ...

Over the past years, stress has been put on global deadlock processing in distributed database management systems. This paper presents the main results of evaluation studies which were intended to provide clues for the choice of a concurrency control ...

In the literature on serializability (see [1]), a transaction is considered to be a finite sequence of operations. As a step towards the handling of more complex evolutions of processes, we assume in this paper that the sequence of operations performed ...

A method is proposed for reasoning about safety and liveness properties of message passing networks. The method is hierarchical and is based upon combining the specifications of component processes to obtain the specification of a network. The inference ...

Concurrency control is the activity of synchronizing operations issued by concurrently executing programs on a shared database. The goal is to produce an execution that has the same effect as a serial (noninterleaved) one.

In a multiversion database ...

The multi-version data item concept is a method for increasing concurrency in a database system. All previously proposed schemes utilizing this concept relied on transaction rollback as a means for preserving consistency. These rollbacks require a ...

An n-failure-resilient protocol for distributed transaction processing regarding site crash, network partitioning, and local failures like abort of subtransactions is specified. The three-phased protocol contains concurrency control, a mechanism ...

A perfect matching in a graph G(V,E), also called a 1-factor, is a collection P of non-interesting edges engaging (incident with) all the vertices; in case G is bipartite V = M @@@@ F, M @@@@ F = φ, P should engage all the vertices of M. The ...

We investigate the complexity of seaching by comparisons a table of n elements on a synchronous, shared memory parallel computer with p processors. We show that O(lgn) steps are required if concurrent access to the same memory cell is not allowed, ...

This paper is about two constructions for transforming planar systolic arrays. By a systolic array we mean a uniformly structured processor configuration that allows only local communication (between neighbour processors) and supports high throughout by ...