Proceedings of the ... International Symposium on High Performance Distributed Computing最新文献

{"title":"Õptimal Dual Vertex Failure Connectivity Labels","authors":"M. Parter, Asaf Petruschka","doi":"10.48550/arXiv.2208.10168","DOIUrl":"https://doi.org/10.48550/arXiv.2208.10168","url":null,"abstract":"In this paper we present succinct labeling schemes for supporting connectivity queries under vertex faults. For a given $n$-vertex graph $G$, an $f$-VFT (resp., EFT) connectivity labeling scheme is a distributed data structure that assigns each of the graph edges and vertices a short label, such that given the labels of a vertex pair $u$ and $v$, and the labels of at most $f$ failing vertices (resp., edges) $F$, one can determine if $u$ and $v$ are connected in $G setminus F$. The primary complexity measure is the length of the individual labels. Since their introduction by [Courcelle, Twigg, STACS '07], FT labeling schemes have been devised only for a limited collection of graph families. A recent work [Dory and Parter, PODC 2021] provided EFT labeling schemes for general graphs under edge failures, leaving the vertex failure case fairly open. We provide the first sublinear $f$-VFT labeling schemes for $f geq 2$ for any $n$-vertex graph. Our key result is $2$-VFT connectivity labels with $O(log^3 n)$ bits. Our constructions are based on analyzing the structure of dual failure replacement paths on top of the well-known heavy-light tree decomposition technique of [Sleator and Tarjan, STOC 1981]. We also provide $f$-VFT labels with sub-linear length (in $|V|$) for any $f=o(loglog n)$, that are based on a reduction to the existing EFT labels.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"13 1","pages":"32:1-32:19"},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83907438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Packet Forwarding with a Locally Bursty Adversary","authors":"Will Rosenbaum","doi":"10.4230/LIPIcs.DISC.2022.4","DOIUrl":"https://doi.org/10.4230/LIPIcs.DISC.2022.4","url":null,"abstract":"We consider packet forwarding in the adversarial queueing theory (AQT) model introduced by Borodin et al. We introduce a refinement of the AQT $(rho, sigma)$-bounded adversary, which we call a emph{locally bursty adversary} (LBA) that parameterizes injection patterns jointly by edge utilization and packet origin. For constant ($O(1)$) parameters, the LBA model is strictly more permissive than the $(rho, sigma)$ model. For example, there are injection patterns in the LBA model with constant parameters that can only be realized as $(rho, sigma)$-bounded injection patterns with $rho + sigma = Omega(n)$ (where $n$ is the network size). We show that the LBA model (unlike the $(rho, sigma)$ model) is closed under packet bundling and discretization operations. Thus, the LBA model allows one to reduce the study of general (uniform) capacity networks and inhomogenous packet sizes to unit capacity networks with homogeneous packets. On the algorithmic side, we focus on information gathering networks -- i.e., networks in which all packets share a common destination, and the union of packet routes forms a tree. We show that the Odd-Even Downhill (OED) forwarding protocol described independently by Dobrev et al. and Patt-Shamir and Rosenbaum achieves buffer space usage of $O(log n)$ against all LBAs with constant parameters. OED is a local protocol, but we show that the upper bound is tight even when compared to centralized protocols. Our lower bound for the LBA model is in contrast to the $(rho, sigma)$-model, where centralized protocols can achieve worst-case buffer space usage $O(1)$ for $rho, sigma = O(1)$, while the $O(log n)$ upper bound for OED is optimal only for local protocols.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"34 1","pages":"34:1-34:18"},"PeriodicalIF":0.0,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85135554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exponential Speedup Over Locality in MPC with Optimal Memory","authors":"A. Balliu, S. Brandt, Manuela Fischer, R. Latypov, Yannic Maus, D. Olivetti, Jara Uitto","doi":"10.48550/arXiv.2208.09453","DOIUrl":"https://doi.org/10.48550/arXiv.2208.09453","url":null,"abstract":"Locally Checkable Labeling ( LCL ) problems are graph problems in which a solution is correct if it satisfies some given constraints in the local neighborhood of each node. Example problems in this class include maximal matching, maximal independent set, and coloring problems. A successful line of research has been studying the complexities of LCL problems on paths/cycles, trees, and general graphs, providing many interesting results for the LOCAL model of distributed computing. In this work, we initiate the study of LCL problems in the low-space Massively Parallel Computation ( MPC ) model. In particular, on forests, we provide a method that, given the complexity of an LCL problem in the LOCAL model, automatically provides an exponentially faster algorithm for the low-space MPC setting that uses optimal global memory, that is, truly linear. While restricting to forests may seem to weaken the result, we emphasize that all known (conditional) lower bounds for the MPC setting are obtained by lifting lower bounds obtained in the distributed setting in tree-like networks (either forests or high girth graphs), and hence the problems that we study are challenging already on forests. Moreover, the most important technical feature of our algorithms is that they use optimal global memory, that is, memory linear in the number of edges of the graph. In contrast, most of the state-of-the-art algorithms use more than linear global memory. Further, they typically start with a dense graph, sparsify it, and then solve the problem on the residual graph, exploiting the relative increase in global memory. On forests, this is not possible, because the given graph is already as sparse as it can be, and using optimal memory requires new solutions. Graph Exponentiation. A reoccurring challenge for all regimes lies in respecting the linear global memory, which roughly means that on average, every node can use only a constant amount of memory. This is particularly unfortunate because almost all recent MPC results – and in particular all that achieve exponential speedups – rely on the memory-intense graph exponentiation technique [45]. Informally, this technique enables a node to gather its 2 k -hop neighborhood in k communication rounds. Doing this in parallel for every node in the graph results in a ∆ 2 k overhead in global memory. For this technique to be useful, k has to be ω (1), yielding a non-constant multiplicative increase in the global memory requirement. In order to use this technique but not violate linear global memory, we develop new solutions that are discussed in the following paragraphs. ▶ Lemma 9. The distance- k O (∆ 2 k ) -coloring problem on general graphs can be solved in the low-space MPC model with a O (log log ∗ n + log k ) -time deterministic algorithm, as long as ∆ k < n δ . The algorithm requires O (∆ k ) words of local and O ( m + n · ∆ k ) words of global memory. If k and ∆ are constants, the runtime reduces to O (log log ∗ n ) and we require","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"22 1","pages":"9:1-9:21"},"PeriodicalIF":0.0,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89174417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smoothed Analysis of Information Spreading in Dynamic Networks","authors":"M. Dinitz, Jeremy T. Fineman, Seth Gilbert, Calvin C. Newport","doi":"10.48550/arXiv.2208.05998","DOIUrl":"https://doi.org/10.48550/arXiv.2208.05998","url":null,"abstract":"The best known solutions for $k$-message broadcast in dynamic networks of size $n$ require $Omega(nk)$ rounds. In this paper, we see if these bounds can be improved by smoothed analysis. We study perhaps the most natural randomized algorithm for disseminating tokens in this setting: at every time step, choose a token to broadcast randomly from the set of tokens you know. We show that with even a small amount of smoothing (one random edge added per round), this natural strategy solves $k$-message broadcast in $tilde{O}(n+k^3)$ rounds, with high probability, beating the best known bounds for $k=o(sqrt{n})$ and matching the $Omega(n+k)$ lower bound for static networks for $k=O(n^{1/3})$ (ignoring logarithmic factors). In fact, the main result we show is even stronger and more general: given $ell$-smoothing (i.e., $ell$ random edges added per round), this simple strategy terminates in $O(kn^{2/3}log^{1/3}(n)ell^{-1/3})$ rounds. We then prove this analysis close to tight with an almost-matching lower bound. To better understand the impact of smoothing on information spreading, we next turn our attention to static networks, proving a tight bound of $tilde{O}(ksqrt{n})$ rounds to solve $k$-message broadcast, which is better than what our strategy can achieve in the dynamic setting. This confirms that although smoothed analysis reduces the difficulties induced by changing graph structures, it does not eliminate them altogether. Finally, we apply our tools to prove an optimal result for $k$-message broadcast in so-called well-mixed networks in the absence of smoothing. By comparing this result to an existing lower bound for well-mixed networks, we establish a formal separation between oblivious and strongly adaptive adversaries with respect to well-mixed token spreading, partially resolving an open question on the impact of adversary strength on the $k$-message broadcast problem.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"85 1","pages":"18:1-18:22"},"PeriodicalIF":0.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83925635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault Tolerant Coloring of the Asynchronous Cycle","authors":"P. Fraigniaud, Patrick Lambein-Monette, M. Rabie","doi":"10.48550/arXiv.2207.11198","DOIUrl":"https://doi.org/10.48550/arXiv.2207.11198","url":null,"abstract":"We present a wait-free algorithm for proper coloring the n nodes of the asynchronous cycle $C_n$, where each crash-prone node starts with its (unique) identifier as input. The algorithm is independent of $n geq 3$, and runs in $mathrm{O}(log^* n)$ rounds in $C_n$. This round-complexity is optimal thanks to a known matching lower bound, which applies even to synchronous (failure-free) executions. The range of colors used by our algorithm, namely ${0, ..., 4}$, is optimal too, thanks to a known lower bound on the minimum number of names for which renaming is solvable wait-free in shared-memory systems, whenever $n$ is a power of a prime. Indeed, our model coincides with the shared-memory model whenever $n = 3$, and the minimum number of names for which renaming is possible in 3-process shared-memory systems is 5.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"6 1","pages":"23:1-23:22"},"PeriodicalIF":0.0,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73603019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On implementing SWMR registers from SWSR registers in systems with Byzantine failures","authors":"Xing Hu, S. Toueg","doi":"10.48550/arXiv.2207.01470","DOIUrl":"https://doi.org/10.48550/arXiv.2207.01470","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 [13], 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 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 malicious -- thus matching the impossibility result. The second implementation assumes process signatures; it is bounded wait-free and linearizable under any combination of process failures. Finally, we show that without process signatures, even if we assume that the writer is correct and at most one of the readers can be malicious, it is impossible to guarantee that every correct reader completes each read operation in a bounded number of steps.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"2 1","pages":"36:1-36:19"},"PeriodicalIF":0.0,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87242760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Holistic Verification of Blockchain Consensus","authors":"N. Bertrand, V. Gramoli, I. Konnov, Marijana Lazi'c, Pierre Tholoniat, Josef Widder","doi":"10.48550/arXiv.2206.04489","DOIUrl":"https://doi.org/10.48550/arXiv.2206.04489","url":null,"abstract":"Blockchain has recently attracted the attention of the industry due, in part, to its ability to automate asset transfers. It requires distributed participants to reach a consensus on a block despite the presence of malicious (a.k.a. Byzantine) participants. Malicious participants exploit regularly weaknesses of these blockchain consensus algorithms, with sometimes devastating consequences. In fact, these weaknesses are quite common and are well illustrated by the flaws in the hand-written proofs of existing blockchain consensus protocols [63]. Paradoxically, until now, no blockchain consensus has been holistically verified using model checking. In this paper, we remedy this paradox by model checking for the first time a blockchain consensus used in industry. We propose a holistic approach to verify the consensus algorithm of the Red Belly Blockchain [20], for any number $n$ of processes and any number $f<n/3$ of Byzantine processes. We decompose directly the algorithm pseudocode in two parts -- an inner broadcast algorithm and an outer decision algorithm -- each modelled as a threshold automaton [36], and we formalize their expected properties in linear-time temporal logic. We then automatically check the inner broadcasting algorithm, under a carefully identified fairness assumption. For the verification of the outer algorithm, we simplify the model of the inner algorithm by relying on its checked properties. Doing so, we formally verify not only the safety properties of the Red Belly Blockchain consensus but also its liveness in about 70 seconds.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"6 1","pages":"10:1-10:24"},"PeriodicalIF":0.0,"publicationDate":"2022-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90266908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved Deterministic Connectivity in Massively Parallel Computation","authors":"Manuela Fischer, Jeff Giliberti, C. Grunau","doi":"10.48550/arXiv.2206.01568","DOIUrl":"https://doi.org/10.48550/arXiv.2206.01568","url":null,"abstract":"A long line of research about connectivity in the Massively Parallel Computation model has culminated in the seminal works of Andoni et al. [FOCS'18] and Behnezhad et al. [FOCS'19]. They provide a randomized algorithm for low-space MPC with conjectured to be optimal round complexity $O(log D + log log_{frac m n} n)$ and $O(m)$ space, for graphs on $n$ vertices with $m$ edges and diameter $D$. Surprisingly, a recent result of Coy and Czumaj [STOC'22] shows how to achieve the same deterministically. Unfortunately, however, their algorithm suffers from large local computation time. We present a deterministic connectivity algorithm that matches all the parameters of the randomized algorithm and, in addition, significantly reduces the local computation time to nearly linear. Our derandomization method is based on reducing the amount of randomness needed to allow for a simpler efficient search. While similar randomness reduction approaches have been used before, our result is not only strikingly simpler, but it is the first to have efficient local computation. This is why we believe it to serve as a starting point for the systematic development of computation-efficient derandomization approaches in low-memory MPC.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"21 1","pages":"22:1-22:17"},"PeriodicalIF":0.0,"publicationDate":"2022-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91056494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to Wake Up Your Neighbors: Safe and Nearly Optimal Generic Energy Conservation in Radio Networks","authors":"Varsha Dani, Thomas P. Hayes","doi":"10.48550/arXiv.2205.12830","DOIUrl":"https://doi.org/10.48550/arXiv.2205.12830","url":null,"abstract":"Recent work has shown that it is sometimes feasible to significantly reduce the energy usage of some radio-network algorithms by adaptively powering down the radio receiver when it is not needed. Although past work has focused on modifying specific network algorithms in this way, we now ask the question of whether this problem can be solved in a generic way, treating the algorithm as a kind of black box. We are able to answer this question in the affirmative, presenting a new general way to modify arbitrary radio-network algorithms in an attempt to save energy. At the expense of a small increase in the time complexity, we can provably reduce the energy usage to an extent that is provably nearly optimal within a certain class of general-purpose algorithms. As an application, we show that our algorithm reduces the energy cost of breadth-first search in radio networks from the previous best bound of $2^{O(sqrt{log n})}$ to $mathrm{polylog}(n)$, where $n$ is the number of nodes in the network A key ingredient in our algorithm is hierarchical clustering based on additive Voronoi decomposition done at multiple scales. Similar clustering algorithms have been used in other recent work on energy-aware computation in radio networks, but we believe the specific approach presented here may be of independent interest.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"17 1","pages":"16:1-16:22"},"PeriodicalIF":0.0,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85927583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distributed Randomness from Approximate Agreement","authors":"Luciano Freitas, P. Kuznetsov, Andrei Tonkikh","doi":"10.48550/arXiv.2205.11878","DOIUrl":"https://doi.org/10.48550/arXiv.2205.11878","url":null,"abstract":"Randomisation is a critical tool in designing distributed systems. The common coin primitive, enabling the system members to agree on an unpredictable random number, has proven to be particularly useful. We observe, however, that it is impossible to implement a truly random common coin protocol in a fault-prone asynchronous system. To circumvent this impossibility, we introduce two relaxations of the perfect common coin: (1) approximate common coin generating random numbers that are close to each other; and (2) Monte Carlo common coin generating a common random number with an arbitrarily small, but non-zero, probability of failure. Building atop the approximate agreement primitive, we obtain efficient asynchronous implementations of the two abstractions, tolerating up to one third of Byzantine processes. Our protocols do not assume trusted setup or public key infrastructure and converge to the perfect coin exponentially fast in the protocol running time. By plugging one of our protocols for Monte Carlo common coin in a well-known consensus algorithm, we manage to get a binary Byzantine agreement protocol with O ( n 3 log n ) communication complexity, resilient against an adaptive adversary, and tolerating the optimal number f < n/ 3 of failures without trusted setup or PKI. To the best of our knowledge, the best communication complexity for binary Byzantine agreement achieved so far in this setting is O ( n 4 ). We also show how the approximate common coin , combined with a variant of Gray code, can be used to solve an interesting problem of Intersecting Random Subsets, which we introduce in this paper.","PeriodicalId":89463,"journal":{"name":"Proceedings of the ... International Symposium on High Performance Distributed Computing","volume":"68 1","pages":"24:1-24:21"},"PeriodicalIF":0.0,"publicationDate":"2022-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75648232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}