This paper examines fundamental trade-offs in fault-tolerant distributed systems and replicated databases built over the Internet. We discuss interplays between consistency, availability, and latency which are in the very nature of globally distributed systems and also analyse their interconnection with durability and energy efficiency. In this paper we put forward an idea that consistency, availability, latency, durability and other properties need to be viewed as more continuous than binary in contrast to the well-known CAP/PACELC theorems. We compare different consistency models and highlight the role of the application timeout, replication factor and other settings that essentially determine the interplay between above properties. Our findings may be of interest to software engineers and system architects who develop Internet-scale distributed computer systems and cloud solutions.
Distributed replicated databases play a crucial role in modern computer systems enabling scalable, fault-tolerant, and high-performance data management. However, achieving these qualities requires resolving a number of trade-offs between various properties during system design and operation. This paper reviews trade-offs in distributed replicated databases and provides a survey of recent research papers studying distributed data storage. The paper first discusses a compromise between consistency and latency that appears in distributed replicated data storages and directly follows from CAP and PACELC theorems. Consistency refers to the guarantee that all clients in a distributed system observe the same data at the same time. To ensure strong consistency, distributed systems typically employ coordination mechanisms and synchronization protocols that involve communication and agreement among distributed replicas. These mechanisms introduce additional overhead and latency and can dramatically increase the time taken to complete operations when replicas are globally distributed across the Internet. In addition, we study trade-offs between other system properties including availability, durability, cost, energy consumption, read and write latency, etc. In this paper we also provide a comprehensive review and classification of recent research works in distributed replicated databases. Reviewed papers showcase several major areas of research, ranging from performance evaluation and comparison of various NoSQL databases to suggest new strategies for data replication and putting forward new consistency models. In particular, we observed a shift towards exploring hybrid consistency models of causal consistency and eventual consistency with causal ordering due to their ability to strike a balance between operations ordering guarantees and high performance. Researchers have also proposed various consistency control algorithms and consensus quorum protocols to coordinate distributed replicas. Insights from this review can empower practitioners to make informed decisions in designing and managing distributed data storage systems as well as help identify existing gaps in the body of knowledge and suggest further research directions.
Бази даних пройшли певний шлях еволюції від архітектури мейнфреймів до глобально-розподілених нереляційних сховищ, що призначені для збереження величезних обсягів інформації та обслуговування мільйонів користувачів. У статті зазначено драйвери та передумови цього розвитку, а також розглянуто трансформацію моделей властивостей систем керування базами даних та теорем, що формалізують відносини між ними. Зокрема, розглянуто обумовленість переходу від моделі властивостей ACID до моделі BASE, яка пом’якшує вимоги до узгодженості даних, що є необхідним для забезпечення високої продуктивності розподілених баз даних з багатьма репліками. Крім того, надано стисле обґрунтування теорем САР та PACELC, які встановлюють взаємовиключні відносини між доступністю, узгодженістю та швидкодією у реплікованих інформаційних системах та проаналізованоо їх обмеження. Зазначено проблеми сумісності моделей узгодженості, що використовуються різними нереляційними сховищами даних, та, в якості прикладу, детально розглянуто можливі налаштування узгодженості NoSQL баз даних Cassandra, MongoDB та Azure CosmosDB. Результати еволюції архітектур розподілених баз даних узагальнено за допомогою нотації GSN (Goal Structuring Notation). Також окреслено подальші напрямки наукових досліджень та шляхи подальшого розвитку глобально-розподілених інформаційних систем та сховищ даних.
This article is devoted to description the realization of the public-key infrastructure using the stateless algorithm of digital signature with quantum-resistance. This article is detail describe the development cycle and implementation of the stateless signature scheme using the hash function of DSTU 7564:2014.
This paper evaluates performance of distributed fault-tolerant computer systems and replicated NoSQL databases and studies the impact of data consistency on performance and throughput on the example of a three-replicated Cassandra cluster. The paper presents results of heavy-load testing (benchmarking) of Cassandra cluster’s read and write performance which replicas were deployed on Amazon EC2 cloud. The presented quantitative results show how different consistency settings affect the performance of a Cassandra cluster under different workloads considering two deployment scenarios: when all cluster replicas are located in the sane data center, and when they are geographically distributed across different data centers (i.e. Amazon availability zones). We propose a new method of minimizing Cassandra response time while ensuring strong data consistency which is based on optimization of consistency settings depending on the current workload and the proportion between read and write operations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.