Distributed Computing最新文献

A wait-free queue with polylogarithmic step complexity 步长复杂度为多对数的无等待队列

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-08-17 DOI: 10.1007/s00446-024-00471-7

Hossein Naderibeni, Eric Ruppert

引用次数: 0

Deterministic near-optimal distributed listing of cliques 确定性近优分布式小群列表

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-06-20 DOI: 10.1007/s00446-024-00470-8

Keren Censor-Hillel, Dean Leitersdorf, David Vulakh

{"title":"Deterministic near-optimal distributed listing of cliques","authors":"Keren Censor-Hillel, Dean Leitersdorf, David Vulakh","doi":"10.1007/s00446-024-00470-8","DOIUrl":"https://doi.org/10.1007/s00446-024-00470-8","url":null,"abstract":"The importance of classifying connections in large graphs has been the motivation for a rich line of work on distributed subgraph finding that has led to exciting recent breakthroughs. A crucial aspect that remained open was whether deterministic algorithms can be as efficient as their randomized counterparts, where the latter are known to be tight up to polylogarithmic factors. We give deterministic distributed algorithms for listing cliques of size p in (n^{1 - 2/p + o(1)}) rounds in the Congest model. For triangles, our (n^{1/3+o(1)}) round complexity improves upon the previous state of the art of (n^{2/3+o(1)}) rounds (Chang and Saranurak, in: 2020 IEEE 61st annual symposium on foundations of computer science (FOCS), pp 377–388. IEEE Computer Society, Los Alamito, 2020. https://doi.org/10.1109/FOCS46700.2020.00043). For cliques of size (p ge 4), ours are the first non-trivial deterministic distributed algorithms. Given known lower bounds, for all values (p ge 3) our algorithms are tight up to an (n^{o(1)}) subpolynomial factor, which comes from the deterministic routing procedure we use.\u0000","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"62 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On implementing SWMR registers from SWSR registers in systems with Byzantine failures 在存在拜占庭故障的系统中从 SWSR 寄存器实现 SWMR 寄存器

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-06-06 DOI: 10.1007/s00446-024-00465-5

Xing Hu, Sam Toueg

{"title":"On implementing SWMR registers from SWSR registers in systems with Byzantine failures","authors":"Xing Hu, Sam Toueg","doi":"10.1007/s00446-024-00465-5","DOIUrl":"https://doi.org/10.1007/s00446-024-00465-5","url":null,"abstract":"The implementation of registers from (potentially) weaker registers is a classical problem in the theory of distributed computing. Since Lamport’s pioneering work (Lamport in Distrib Comput 1(2):77–101, 1986), this problem has been extensively studied in the context of asynchronous processes with crash failures. In this paper, we investigate this problem in the context of Byzantine process failures, with and without process signatures. We first prove that, without signatures, there is no wait-free linearizable implementation of a 1-writer n-reader register from atomic 1-writer 1-reader registers. In fact, we show a stronger result, namely, even under the assumption that the writer can only crash and at most one reader can be malicious, there is no linearizable implementation of a 1-writer n-reader register from atomic 1-writer ((n-1))-reader registers that ensures that every correct process eventually completes its operations. In light of this impossibility result, we give two implementations of a 1-writer n-reader register from atomic 1-writer 1-reader registers that work under different assumptions. The first implementation is linearizable (under any combination of Byzantine process failures), but it guarantees that every correct process eventually completes its operations only under the assumption that the writer is correct or no reader is Byzantine—thus matching the impossibility result. The second implementation assumes process signatures; it is wait-free and linearizable under any number and combination of Byzantine process failures.\u0000","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"40 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141549333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Developing Irelands first National Student Mental Health and Suicide Prevention Framework for Higher Education. 制定爱尔兰第一个全国高等教育学生心理健康和自杀预防框架。

IF 1.8 4区计算机科学

Distributed Computing Pub Date : 2024-06-01 Epub Date: 2022-04-05 DOI: 10.1017/ipm.2022.10

J Surdey, D Byrne, T Fox

{"title":"Developing Irelands first National Student Mental Health and Suicide Prevention Framework for Higher Education.","authors":"J Surdey, D Byrne, T Fox","doi":"10.1017/ipm.2022.10","DOIUrl":"10.1017/ipm.2022.10","url":null,"abstract":"This article focuses on the development of Ireland's first National Student Mental Health and Suicide Prevention Framework for Higher Education. There is growing concern for student mental health in higher education nationally and globally. The majority of students are aged between 18 and 24, which is identified as a high-risk group for mental health difficulties. Recent surveys of student mental illness, mental distress, and low well-being have been recognized by the World Health Organization, the Union of Students in Ireland National Report on Student Mental Health in Third Level Education, the My World survey and the My World 2 study. The Higher Education Authority in Ireland made a commitment to the Department of Health Connecting for Life (Ireland's National Strategy to Reduce Suicide 2015-2020) to form national guidelines for suicide prevention in higher education. In order to deliver on this commitment, The National Student Mental Health and Suicide Prevention Framework was developed. The Framework is informed by international evidence and was the product of a collaborative cross sector and cross disciplinary team including health professionals, government representatives, educators, students, policy makers, community organizations, researchers and clinicians.","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"1 1","pages":"254-258"},"PeriodicalIF":1.8,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89836997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Asymmetric distributed trust 非对称分布式信任

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-05-28 DOI: 10.1007/s00446-024-00469-1

Orestis Alpos, Christian Cachin, Björn Tackmann, Luca Zanolini

引用次数: 0

Iterative approximate Byzantine consensus in arbitrary directed graphs 任意有向图中的迭代近似拜占庭共识

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-05-22 DOI: 10.1007/s00446-024-00468-2

Lewis Tseng, Guanfeng Liang, Nitin H. Vaidya

{"title":"Iterative approximate Byzantine consensus in arbitrary directed graphs","authors":"Lewis Tseng, Guanfeng Liang, Nitin H. Vaidya","doi":"10.1007/s00446-024-00468-2","DOIUrl":"https://doi.org/10.1007/s00446-024-00468-2","url":null,"abstract":"This paper identifies necessary and sufficient conditions for the existence of iterative algorithms that achieve approximate Byzantine consensus in arbitrary directed graphs, where each directed link represents a communication channel between a pair of nodes. The class of iterative algorithms considered in this paper ensures that, after each iteration of the algorithm, the state of each fault-free node remains in the convex hull of the states of the fault-free nodes at the end of the previous iteration. We present the necessary and sufficient condition for the existence of such iterative consensus algorithms in synchronous arbitrary point-to-point networks in presence of Byzantine faults in two different equivalent forms. We prove the necessity using an indistinguishability argument. For sufficiency, we develop a proof framework, which first uses a series of “transition matrices” to model the state evolution of the fault-free nodes using our algorithm, and then proves the correctness by identifying important properties of the matrices. The proof framework is useful for other iterative fault-tolerant algorithms. We discuss the extensions to asynchronous systems and the Byzantine links fault model.","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"28 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141153650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Liveness and latency of Byzantine state-machine replication 拜占庭状态机复制的有效性和延迟

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-05-03 DOI: 10.1007/s00446-024-00466-4

Manuel Bravo, Gregory Chockler, Alexey Gotsman

{"title":"Liveness and latency of Byzantine state-machine replication","authors":"Manuel Bravo, Gregory Chockler, Alexey Gotsman","doi":"10.1007/s00446-024-00466-4","DOIUrl":"https://doi.org/10.1007/s00446-024-00466-4","url":null,"abstract":"Byzantine state-machine replication (SMR) ensures the consistency of replicated state in the presence of malicious replicas and lies at the heart of the modern blockchain technology. Byzantine SMR protocols often guarantee safety under all circumstances and liveness only under synchrony. However, guaranteeing liveness even under this assumption is nontrivial. So far we have lacked systematic ways of incorporating liveness mechanisms into Byzantine SMR protocols, which often led to subtle bugs. To close this gap, we introduce a modular framework to facilitate the design of provably live and efficient Byzantine SMR protocols. Our framework relies on a view abstraction generated by a special SMR synchronizer primitive to drive the agreement on command ordering. We present a simple formal specification of an SMR synchronizer and its bounded-space implementation under partial synchrony. We also apply our specification to prove liveness and analyze the latency of three Byzantine SMR protocols via a uniform methodology. In particular, one of these results yields what we believe is the first rigorous liveness proof for the algorithmic core of the seminal PBFT protocol.\u0000","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"17 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140886522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Asynchronous opinion dynamics in social networks 社交网络中的异步舆论动态

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-04-26 DOI: 10.1007/s00446-024-00467-3

Petra Berenbrink, Martin Hoefer, Dominik Kaaser, Pascal Lenzner, Malin Rau, Daniel Schmand

{"title":"Asynchronous opinion dynamics in social networks","authors":"Petra Berenbrink, Martin Hoefer, Dominik Kaaser, Pascal Lenzner, Malin Rau, Daniel Schmand","doi":"10.1007/s00446-024-00467-3","DOIUrl":"https://doi.org/10.1007/s00446-024-00467-3","url":null,"abstract":"Opinion spreading in a society decides the fate of elections, the success of products, and the impact of political or social movements. A prominent model to study opinion formation processes is due to Hegselmann and Krause. It has the distinguishing feature that stable states do not necessarily show consensus, i.e., the population of agents might not agree on the same opinion. We focus on the social variant of the Hegselmann–Krause model. There are n agents, which are connected by a social network. Their opinions evolve in an iterative, asynchronous process, in which agents are activated one after another at random. When activated, an agent adopts the average of the opinions of its neighbors having a similar opinion (where similarity of opinions is defined using a parameter (varepsilon )). Thus, the set of influencing neighbors of an agent may change over time. We show that such opinion dynamics are guaranteed to converge for any social network. We provide an upper bound of ({text {O}}(n|E|^2 (varepsilon /delta )^2)) on the expected number of opinion updates until convergence to a stable state, where (|E|) is the number of edges of the social network, and (delta ) is a parameter of the stability concept. For the complete social network we show a bound of ({text {O}}(n^3(n^2 + (varepsilon /delta )^2))) that represents a major improvement over the previously best upper bound of ({text {O}}(n^9 (varepsilon /delta )^2)).","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"27 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the power of bounded asynchrony: convergence by autonomous robots with limited visibility 有界异步的力量：能见度有限的自主机器人的趋同性

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-04-09 DOI: 10.1007/s00446-024-00463-7

David Kirkpatrick, Irina Kostitsyna, Alfredo Navarra, Giuseppe Prencipe, Nicola Santoro

{"title":"On the power of bounded asynchrony: convergence by autonomous robots with limited visibility","authors":"David Kirkpatrick, Irina Kostitsyna, Alfredo Navarra, Giuseppe Prencipe, Nicola Santoro","doi":"10.1007/s00446-024-00463-7","DOIUrl":"https://doi.org/10.1007/s00446-024-00463-7","url":null,"abstract":"A distributed algorithm ({mathcal {A}}) solves the Point Convergence task if an arbitrarily large collection of entities, starting in an arbitrary configuration, move under the control of ({mathcal {A}}) to eventually form and thereafter maintain configurations in which the separation between all entities is arbitrarily small. This fundamental task in the standard (mathcal {OBLOT}) model of autonomous mobile entities has been previously studied in a variety of settings, including full visibility, exact measurements (including distances and angles), and synchronous activation of entities. Our study concerns the minimal assumptions under which entities, moving asynchronously with limited and unknown visibility range and subject to limited imprecision in measurements, can be guaranteed to converge in this way. We present an algorithm operating under these constraints that solves Point Convergence, for entities moving in two or three dimensional space, with any bounded degree of asynchrony. We also prove that under similar realistic constraints, but unbounded asynchrony, Point Convergence in the plane is not possible in general, contingent on the natural assumption that algorithms maintain the (visible) connectivity among entities present in the initial configuration. This variant, that we call Cohesive Convergence, serves to distinguish the power of bounded and unbounded asynchrony in the control of autonomous mobile entities, settling a long-standing question whether in the Euclidean plane synchronously scheduled entities are more powerful than asynchronously scheduled entities.","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"2675 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Good-case early-stopping latency of synchronous byzantine reliable broadcast: the deterministic case 同步拜占庭可靠广播的良好情况早期停止延迟：确定性案例

IF 1.3 4区计算机科学

Distributed Computing Pub Date : 2024-03-22 DOI: 10.1007/s00446-024-00464-6

Timothé Albouy, Davide Frey, Michel Raynal, François Taïani

{"title":"Good-case early-stopping latency of synchronous byzantine reliable broadcast: the deterministic case","authors":"Timothé Albouy, Davide Frey, Michel Raynal, François Taïani","doi":"10.1007/s00446-024-00464-6","DOIUrl":"https://doi.org/10.1007/s00446-024-00464-6","url":null,"abstract":"This paper considers the good-case latency of Byzantine Reliable Broadcast (BRB), i.e., the time taken by correct processes to deliver a message when the initial sender is correct. This time plays a crucial role in the performance of practical distributed systems. Although significant strides have been made in recent years on this question, progress has mainly focused on either asynchronous or randomized algorithms. By contrast, the good-case latency of deterministic synchronous BRB under a majority of Byzantine faults has been little studied. In particular, it was not known whether a good-case latency below the worst-case bound of (t+1) rounds could be obtained. This work answers this open question positively and proposes a deterministic synchronous Byzantine reliable broadcast that achieves a good-case latency of (textsf{max} (2,t+3-c)) rounds (or equivalently (textsf{max} (2,f+t+3-n))), where t is the upper bound on the number of Byzantine processes, (fle t) the number of effectively Byzantine processes, and (c=n-f) the number of effectively correct processes. The proposed algorithm does not put any constraint on t, and assumes an authenticated setting, in which individual processes can sign the messages they send, and verify the authenticity of the signatures they receive.","PeriodicalId":50569,"journal":{"name":"Distributed Computing","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140204000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0