Asynchronous Consistency
نویسنده
چکیده
Many database applications tolerate a certain amount of data inconsistency to gain increased concurrent processing and to accommodate real-world constraints. This paper describes how inconsistency can be modeled in a database and managed with consistency restoration methods. The correctness criterion for the maintenance of inconsistency is epsilon serializability (ESR). An informal notation to characterize inconsistency and several consistency restoration techniques are described.
منابع مشابه
Consistency Maintenance for ABT
One of the most powerful techniques for solving centralized constraint satisfaction problems (CSPs) consists of maintaining local consistency during backtrack search (e.g. [11]). Yet, no work has been reported on such a combination in asynchronous settings. The difficulty in this case is that, in the usual algorithms, the instantiation and consistency enforcement steps must alternate sequential...
متن کاملChecking Behavioral Consistency Constraints for Pervasive Context in Asynchronous Environments
Context consistency checking, the checking of specified constraint on properties of contexts, is essential to contextaware applications. In order to delineate and adapt to dynamic changes in the pervasive computing environment, context-aware applications often need to specify and check behavioral consistency constraints over the contexts. This problem is challenging mainly due to the distribute...
متن کاملAsynchronous PFC-MRDAC±Adopt —Consistency-Maintenance in Adopt—
Each agent has private problems. Private concerns can often be formulated in a general framework such as constraint satisfaction (where everything is modeled by either variables, values, or constraints). Often agents need to find agreement with others for the allocation of final resources. The constraint satisfaction (CSPs) is only a special case of optimization. Here it is shown how a very gen...
متن کاملHOWTO: Asynchronous PFC-MRDAC -Optimization in Distributed Constraint Problems±Adopt-
Each agent has private problems. Private concerns can often be formulated in a general framework such as constraint satisfaction (where everything is modeled by either variables, values, or constraints). Often agents need to find agreement with others for the allocation of final resources. The constraint satisfaction (CSPs) is only a special case of optimization. Here it is shown how a very gen...
متن کاملAsynchronous Reconfiguration for Paxos State Machines
This paper addresses reconfiguration of a Replicated State Machine (RSM) in an asynchronous system. It is well known that consensus cannot be solved in an asynchronous system. Therefore an RSM providing strong consistency, cannot guarantee progress in an asynchronous system. However, we show that reconfiguring the RSM is possible in a purely asynchronous system. This differs from all existing r...
متن کاملConsistency, Availability, and Convergence
We examine the limits of consistency in highly available and fault-tolerant distributed storage systems. We introduce a new property—convergence—to explore the these limits in a useful manner. Like consistency and availability, convergence formalizes a fundamental requirement of a storage system: writes by one correct node must eventually become observable to other connected correct nodes. Usin...
متن کامل