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52
PowerGraph: Distributed Graph-Parallel Computation on Natural Graphs
"... Large-scale graph-structured computation is central to tasks ranging from targeted advertising to natural language processing and has led to the development of several graph-parallel abstractions including Pregel and GraphLab. However, the natural graphs commonly found in the real-world have highly ..."
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Cited by 117 (4 self)
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Large-scale graph-structured computation is central to tasks ranging from targeted advertising to natural language processing and has led to the development of several graph-parallel abstractions including Pregel and GraphLab. However, the natural graphs commonly found in the real-world have highly skewed power-law degree distributions, which challenge the assumptions made by these abstractions, limiting performance and scalability. In this paper, we characterize the challenges of computation on natural graphs in the context of existing graphparallel abstractions. We then introduce the PowerGraph abstraction which exploits the internal structure of graph programs to address these challenges. Leveraging the PowerGraph abstraction we introduce a new approach to distributed graph placement and representation that exploits the structure of power-law graphs. We provide a detailed analysis and experimental evaluation comparing PowerGraph to two popular graph-parallel systems. Finally, we describe three different implementation strategies for PowerGraph and discuss their relative merits with empirical evaluations on large-scale real-world problems demonstrating order of magnitude gains. 1
GraphChi: Large-scale Graph Computation On just a PC
- In Proceedings of the 10th USENIX conference on Operating Systems Design and Implementation, OSDI’12
, 2012
"... Current systems for graph computation require a distributed computing cluster to handle very large real-world problems, such as analysis on social networks or the web graph. While distributed computational resources have become more accessible, developing distributed graph algorithms still remains c ..."
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Cited by 109 (6 self)
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Current systems for graph computation require a distributed computing cluster to handle very large real-world problems, such as analysis on social networks or the web graph. While distributed computational resources have become more accessible, developing distributed graph algorithms still remains challenging, especially to non-experts. In this work, we present GraphChi, a disk-based system for computing efficiently on graphs with billions of edges. By using a well-known method to break large graphs into small parts, and a novel parallel sliding windows method, GraphChi is able to execute several advanced data mining, graph mining, and machine learning algorithms on very large graphs, using just a single consumer-level computer. We further extend GraphChi to support graphs that evolve over time, and demonstrate that, on a single computer, GraphChi can process over one hundred thousand graph updates per second, while simultaneously performing computation. We show, through experiments and theoretical analysis, that GraphChi performs well on both SSDs and rotational hard drives. By repeating experiments reported for existing distributed systems, we show that, with only fraction of the resources, GraphChi can solve the same problems in very reasonable time. Our work makes large-scale graph computation available to anyone with a modern PC. 1
GPS: A Graph Processing System ∗
"... GPS (for Graph Processing System) is a complete open-source system we developed for scalable, fault-tolerant, and easy-to-program execution of algorithms on extremely large graphs. GPS is similar to Google’s proprietary Pregel system [MAB+ 11], with some useful additional functionality described in ..."
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Cited by 63 (3 self)
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GPS (for Graph Processing System) is a complete open-source system we developed for scalable, fault-tolerant, and easy-to-program execution of algorithms on extremely large graphs. GPS is similar to Google’s proprietary Pregel system [MAB+ 11], with some useful additional functionality described in the paper. In distributed graph processing systems like GPS and Pregel, graph partitioning is the problem of deciding which vertices of the graph are assigned to which compute nodes. In addition to presenting the GPS system itself, we describe how we have used GPS to study the effects of different graph partitioning schemes. We present our experiments on the performance of GPS under different static partitioning schemes—assigning vertices to workers “intelligently ” before the computation starts—and with GPS’s dynamic repartitioning feature, which reassigns vertices to different compute nodes during the computation by observing their message sending patterns. 1
Parallel breadth-first search on distributed memory systems
, 2011
"... Data-intensive, graph-based computations are pervasive in several scientific applications, and are known to to be quite challenging to implement on distributed memory systems. In this work, we explore the design space of parallel algorithms for Breadth-First Search (BFS), a key subroutine in several ..."
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Cited by 34 (9 self)
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Data-intensive, graph-based computations are pervasive in several scientific applications, and are known to to be quite challenging to implement on distributed memory systems. In this work, we explore the design space of parallel algorithms for Breadth-First Search (BFS), a key subroutine in several graph algorithms. We present two highly-tuned parallel approaches for BFS on large parallel systems: a levelsynchronous strategy that relies on a simple vertex-based partitioning of the graph, and a two-dimensional sparse matrix partitioning-based approach that mitigates parallel communication overhead. For both approaches, we also present hybrid versions with intra-node multithreading. Our novel hybrid two-dimensional algorithm reduces communication times by up to a factor of 3.5, relative to a common vertex based approach. Our experimental study identifies execution regimes in which these approaches will be competitive, and we demonstrate extremely high performance on leading distributed-memory parallel systems. For instance, for a 40,000-core parallel execution on Hopper, an AMD Magny-Cours based system, we achieve a BFS performance rate of 17.8 billion edge visits per second on an undirected graph of 4.3 billion vertices and 68.7 billion edges with skewed degree distribution. 1.
A Flexible Open-Source Toolbox for Scalable Complex Graph Analysis
, 2011
"... The Knowledge Discovery Toolbox (KDT) enables domain experts to perform complex analyses of huge datasets on supercomputers using a high-level language without grappling with the difficulties of writing parallel code, calling parallel libraries, or becoming a graph expert. KDT provides a flexible Py ..."
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Cited by 19 (3 self)
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The Knowledge Discovery Toolbox (KDT) enables domain experts to perform complex analyses of huge datasets on supercomputers using a high-level language without grappling with the difficulties of writing parallel code, calling parallel libraries, or becoming a graph expert. KDT provides a flexible Python interface to a small set of high-level graph operations; composing a few of these operations is often sufficient for a specific analysis. Scalability and performance are delivered by linking to a state-of-the-art back-end compute engine that scales from laptops to large HPC clusters. KDT delivers very competitive performance from a generalpurpose, reusable library for graphs on the order of 10 billion edges and greater. We demonstrate speedup of 1 and 2 orders of magnitude over PBGL and Pegasus, respectively, on some tasks. Examples from simple use cases and key graphanalytic benchmarks illustrate the productivity and performance realized by KDT users. Semantic graph abstractions provide both flexibility and high performance for real-world use cases. Graph-algorithm researchers benefit from the ability to develop algorithms quickly using KDT’s graph and underlying matrix abstractions for distributed memory. KDT is available as open-source code to foster experimentation.
GraphX: Graph Processing in a Distributed Dataflow Framework
- USENIX ASSOCIATION 11TH USENIX SYMPOSIUM ON OPERATING SYSTEMS DESIGN AND IMPLEMENTATION (OSDI ’14)
, 2014
"... In pursuit of graph processing performance, the systems community has largely abandoned general-purpose dis-tributed dataflow frameworks in favor of specialized graph processing systems that provide tailored programming ab-stractions and accelerate the execution of iterative graph algorithms. In thi ..."
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Cited by 16 (0 self)
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In pursuit of graph processing performance, the systems community has largely abandoned general-purpose dis-tributed dataflow frameworks in favor of specialized graph processing systems that provide tailored programming ab-stractions and accelerate the execution of iterative graph algorithms. In this paper we argue that many of the advan-tages of specialized graph processing systems can be re-covered in a modern general-purpose distributed dataflow system. We introduce GraphX, an embedded graph pro-cessing framework built on top of Apache Spark, a widely used distributed dataflow system. GraphX presents a fa-miliar composable graph abstraction that is sufficient to express existing graph APIs, yet can be implemented us-ing only a few basic dataflow operators (e.g., join, map, group-by). To achieve performance parity with special-ized graph systems, GraphX recasts graph-specific op-timizations as distributed join optimizations and mate-rialized view maintenance. By leveraging advances in distributed dataflow frameworks, GraphX brings low-cost fault tolerance to graph processing. We evaluate GraphX on real workloads and demonstrate that GraphX achieves an order of magnitude performance gain over the base dataflow framework and matches the performance of spe-cialized graph processing systems while enabling a wider range of computation.
Highly Parallel Sparse Matrix-Matrix Multiplication
, 2010
"... Generalized sparse matrix-matrix multiplication is a key primitive for many high performance graph algorithms as well as some linear solvers such as multigrid. We present the first parallel algorithms that achieve increasing speedups for an unbounded number of processors. Our algorithms are based on ..."
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Cited by 16 (4 self)
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Generalized sparse matrix-matrix multiplication is a key primitive for many high performance graph algorithms as well as some linear solvers such as multigrid. We present the first parallel algorithms that achieve increasing speedups for an unbounded number of processors. Our algorithms are based on two-dimensional block distribution of sparse matrices where serial sections use a novel hypersparse kernel for scalability. We give a state-of-the-art MPI implementation of one of our algorithms. Our experiments show scaling up to thousands of processors on a variety of test scenarios.
Parallel Community Detection for Massive Graphs
"... Abstract. Tackling the current volume of graph-structured data requires parallel tools. We extend our work on analyzing such massive graph data with the first massively parallel algorithm for community detection that scales to current data sizes, scaling to graphs of over 122 million vertices and ne ..."
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Cited by 15 (4 self)
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Abstract. Tackling the current volume of graph-structured data requires parallel tools. We extend our work on analyzing such massive graph data with the first massively parallel algorithm for community detection that scales to current data sizes, scaling to graphs of over 122 million vertices and nearly 2 billion edges in under 7300 seconds on a massively multithreaded Cray XMT. Our algorithm achieves moderate parallel scalability without sacrificing sequential operational complexity. Community detection partitions a graph into subgraphs more densely connected within the subgraph than to the rest of the graph. We take an agglomerative approach similar to Clauset, Newman, and Moore’s sequential algorithm, merging pairs of connected intermediate subgraphs to optimize different graph properties. Working in parallel opens new approaches to high performance. On smaller data sets, we find the output’s modularity compares well with the standard sequential algorithms.
Communication Optimal Parallel Multiplication of Sparse Random Matrices
, 2013
"... Parallel algorithms for sparse matrix-matrix multiplication typically spend most of their time on inter-processor communication rather than on computation, and hardware trends predict the relative cost of communication will only increase. Thus, sparse matrix multiplication algorithms must minimize c ..."
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Cited by 10 (6 self)
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Parallel algorithms for sparse matrix-matrix multiplication typically spend most of their time on inter-processor communication rather than on computation, and hardware trends predict the relative cost of communication will only increase. Thus, sparse matrix multiplication algorithms must minimize communication costs in order to scale to large processor counts. In this paper, we consider multiplying sparse matrices corresponding to Erdős-Rényi random graphs on distributedmemory parallel machines. We prove a new lower bound on the expected communication cost for a wide class of algorithms. Our analysis of existing algorithms shows that, while some are optimal for a limited range of matrix density and number of processors, none is optimal in general. We obtain two new parallel algorithms and prove that they match the expected communication cost lower bound, and hence they are optimal.
Scalable multi-threaded community detection in social networks
- in Workshop on Multithreaded Architectures and Applications (MTAAP
, 2012
"... Abstract—The volume of existing graphstructured data requires improved parallel tools and algorithms. Finding communities, smaller subgraphs densely connected within the subgraph than to the rest of the graph, plays a role both in developing new parallel algorithms as well as opening smaller portion ..."
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Cited by 9 (2 self)
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Abstract—The volume of existing graphstructured data requires improved parallel tools and algorithms. Finding communities, smaller subgraphs densely connected within the subgraph than to the rest of the graph, plays a role both in developing new parallel algorithms as well as opening smaller portions of the data to current analysis tools. We improve performance of our parallel community detection algorithm by 20 % on the massively multithreaded Cray XMT, evaluate its performance on the next-generation Cray XMT2, and extend its reach to Intel-based platforms with OpenMP. To our knowledge, not only is this the first massively parallel community detection algorithm but also the only such algorithm that achieves excellent performance and good parallel scalability across all these platforms. Our implementation analyzes a moderate sized graph with 105 million vertices and 3.3 billion edges in around 500 seconds on a four processor, 80-logical-core Intel-based system and 1100 seconds on a 64-processor Cray XMT2.
