Causally and totally ordered communication support (CATOCS) has been proposed as important to provide as part of the basic building blocks for constructing reliable distributed systems. In this paper, we identify four major limitations to CATOCS, investigate the applicability of CATOCS to several classes of distributed applications in light of these limitations, and the potential impact of these facilities on communication scalability and robustness. From this investigation, we find limited merit and several potential problems in using CATOCS. The fundamental difficulty with the CATOCS is that it attempts to solve problems at the communication level in violation of the well-known "end-to-end" argument.

Research can rarely be performed on large-scale, distributed systems at the level of thousands of workstations. In this paper, we describe the motivating constraints, design principles, and architecture for an extensible, distributed system operating in such an environment. The constraints include continuous operation, dynamic system evolution, and integration with extant systems. The Information Bus, our solution, is a novel synthesis of four design principles: core communication protocols have minimal semantics, objects are self-describing, types can be dynamically defined, and communication is anonymous. The current implementation provides both flexibility and high performance, and has been proven in several commercial environments, including integrated circuit fabrication plants and brokerage/trading floors.

A data management protocol for executing transactions on a replicated database is presented. The protocol ensures one-copy serializability. i.e., the concurrent execution of transactions on a replicated database is equivalent to some serial execution of the same transactions on a non-replicated database. The protocol tolerates a large class of failures, including: processor and communication link crashes, partitioning of the communication network, lost messages, and slow responses of processors and communication links. Processor and link recoveries are also handled. The protocol implements the reading of a replicated object efficiently by reading the nearest available copy of the object. When reads outnumber writes, the protocol performs better than other known protocols.

A total failure occurs whenever all processes cooperatively executing a distributed task fail before the task completes. A frequent prerequisite for recovery from a total failure is identification of the last set (LAST) of processes to fail. Necessary and sufficient conditions are derived here for computing LAST from the local failure data of recovered processes. These conditions are then translated into procedures for deciding LAST membership, using either complete or incomplete failure data. The choice of failure data is itself dictated by two requirements: (1) it can be cheaply maintained, and (2) it must afford maximum fault-tolerance in the sense that the expected number of recoveries required for identifying LAST is minimized.

This paper presents a taxonomy of consensus problems, based on their safeness and liveness properties, and then explores the relationships among the different problems in the taxonomy. Each problem is characterized by the communication patterns of protocols solving it. This then becomes the basis for a new notion of reducibility between problems. Formally, problem P1 reduces to problem P2 whenever each set of communication patterns of a protocol for P2 is the set of communication patterns of a protocol for P1. This means intuitively that any protocol for P2 can solve P1 by relabeling local states and padding messages. Consequently, the message complexity (measured in number of messages) of P1 is not greater than the message complexity of P2. Our method of characterizing and comparing problems is the principal contribution of this paper.

Article Free Access Share on Increasing availability in partitioned database systems Authors: Dale Skeen Cornell University, Ithaca, New York Cornell University, Ithaca, New YorkView Profile , David D. Wright Prime Computer Inc., Framingham, Massachusetts Prime Computer Inc., Framingham, MassachusettsView Profile Authors Info & Claims PODS '84: Proceedings of the 3rd ACM SIGACT-SIGMOD symposium on Principles of database systemsApril 1984 Pages 290–299https://doi.org/10.1145/588011.588054Online:02 April 1984Publication History 26citation248DownloadsMetricsTotal Citations26Total Downloads248Last 12 Months11Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

A commitment protocol orchestrates the execution of a distributed transaction, allowing each participant to “vote” on the transaction and then applying a pre-specified rule to decide the outcome (commit or abort). A nonblocking commitment protocol is able to correctly terminate a transaction at all operational participants in the presence of any number of benign processor failures. Herein, we derive strong lower bounds for both nonblocking protocols and their less fault-tolerant blocking counterparts. Results on message complexity are both surprising and encouraging: the message complexities of the two classes of protocols are identical. Results on time complexity were less encouraging: nonblocking protocols are approximately 50% more expensive. However, we show how to overlap nonblocking executions of interfering transactions and thereby reduce their extra cost.

We describe a reliability algorithm being considered for DDM, a distributed database system under development at Computer Corporation of America. The algorithm is designed to tolerate clean site failures in which sites simply stop running. The algorithm allows the system to reconfigure itself to run correctly as sites fail and recover. The algorithm solves the subproblems of atomic commit and replicated data handling in an integrated manner.

Article Free Access Share on Determining the last process to fail Author: Dale Skeen Cornell University, Ithaca, New York Cornell University, Ithaca, New YorkView Profile Authors Info & Claims PODS '83: Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systemsMarch 1983Pages 16–24https://doi.org/10.1145/588058.588062Published:21 March 1983Publication History 6citation154DownloadsMetricsTotal Citations6Total Downloads154Last 12 Months1Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Adaplex is an integrated language for programming database applications. It results from the embedding of the database sublanguage DAPLEX in the general purpose programming language Ada. This paper provides an overview of the DDM: a distributed database manager (DDM) that supports the use of Adaplex as an interface language. The important technical innovations we have incorporated in the design of this system include:1. An advanced data model that captures more application semantics than conventional data models.2. Support for flexible data distribution options that improve locality of reference and efficiency of query processing.3. Extensive query optimization that combines compile time access path optimization with run time site selection.4. Efficient transaction management that reduces transaction conflicts and improves the resiliency of replicated data.5. Robust, incremental recovery management that provides for automatic recovery from certain "catastrophic" failure conditions.

A formal model for atomic commit protocols for a distributed database system is introduced. The model is used to prove existence results about resilient protocols for site failures that do not partition the network and then for partitioned networks. For site failures, a pessimistic recovery technique, called independent recovery, is introduced and the class of failures for which resilient protocols exist is identified. For partitioned networks, two cases are studied: the pessimistic case in which messages are lost, and the optimistic case in which no messages are lost. In all cases, fundamental limitations on the resiliency of protocols are derived.

Protocols that allow operational sites to continue transaction processing even though site failures have occurred are called nonblocking. Many applications require nonblocking protocols. This paper investigates the properties of nonblocking protocols. Necessary and sufficient conditions for a protocol to be nonblocking are presented and from these conditions a method for designing them is derived. Both a central site nonblocking protocol and a decentralized nonblocking protocol are presented.