Processing large-scale graphs with billions to trillions of edges requires efficiently utilizing parallel systems. However, current graph processing engines do not scale well beyond a few tens of computing nodes because they are oblivious to the communication cost variations across the interconnection hierarchy. We introduce GraphCube, a better approach to optimizing graph processing on large-scale parallel systems with complex interconnections. GraphCube features a new graph partitioning approach to achieve better load balancing and minimize communication overhead across multiple levels of the interconnection hierarchy. We evaluate GraphCube by applying it to fundamental graph operations performed on synthetic and real-world graph datasets. Our evaluation used up to 79,024 computing nodes and 1.2+ million processor cores. Our large-scale experiments show that GraphCube outperforms state-of-the-art parallel graph processing methods in throughput and scalability. Furthermore, GraphCube outperformed the top-ranked systems on the Graph 500 list.

As graph size (numbers of vertices and edges) is increasing from billions to trillions, efficient graph processing requires exascale computing clusters, which consist of hundreds of thousands of nodes connected via hierarchical networks with multiple levels of communication domains, e.g., multilevel triangle communication domains. While the computation of traversal-centric graph algorithms is relatively simple (e.g., status check), communication is the bottleneck due to the transfer of numerous small messages among hierarchical triangle communication domains.

The graph has recently enabled substantial advances in big data analysis. As graphs are increasing from billions to trillions, efficient graph processing requires large-scale distributed clusters, which have up to thousands of nodes. For big data applications of which the computation is relatively simple, while the communication, especially for imbalanced communication is the bottleneck on distributed clusters, where huge numbers of small messages are transferred through 2D-topology networks. Graph partitioning is the dominant factor to affect the performance of large-scale distributed graph processing. Current graph partitioning policies have paid extensive attention to the utilization of the power law of big graphs but failed to exploit the advanced architectural benefits of 2D topology. To address such a problem, this paper presents GraphMedia, a communication-balanced graph partitioning for distributed search at scale. The key idea of GraphMedia is a communication-balanced partitioning to balance communication based on hardware/software co-design, in which the power law of graphs would be explored to average communication among nodes, and communication would be balanced between row and column by leveraging advanced 2D-topology knowledge. We use both benchmarks and real-world graphs to validate GraphMedia. Specially, GraphMedia-based Graph500 tests on the Tianhe supercomputer are superior to the fastest systems in the latest Graph500 lists (June 2022). We finally apply GraphMedia to real-world graphs for online graph media access, which outperforms the state-of-the-art graph partitioning and graph system by orders of magnitude.

Ankit Srivastava et al. (Srivastava et al. 2020) proposed a parallel framework for Constraint-Based Bayesian Network (BN) Learning via Markov Blanket Discovery (referred to as ramBLe) and implemented it over three existing BN learning algorithms, namely, GS, IAMB and Inter-IAMB. As part of the Student Cluster Competition at SC21, we reproduce the computational efficiency of ramBLe on our assigned Oracle cluster. The cluster has 4x36 cores in total with 100 Gbps RoCE v2 support and is equipped with CentOS-compatible Oracle Linux. Our experiments, covering the same three algorithms of the original ramBLe article (Srivastava et al. 2020), evaluate the strong and weak scalability of the algorithms using real COVID-19 data sets. We verify part of the conclusions from the original article and propose our explanation of the differences obtained in our results.Author: Please confirm or add details for any funding or financial support for the research of this article. ?>

As intelligent transportation systems (ITS) are now being integrated into our everyday lives, it has been widely accepted that forecasting road networks is a promising killer engine for ITS with high social and economic benefits. However, current solutions ignore the heterogeneity of spatial-temporal traffic data and fail to capture hidden spatial-temporal correlations. This paper presents STEGNN: a novel spatial-temporal embedding graph neural network for road network forecasting. The key idea of STEGNN is utilizing Cosine Similarity to generate a high-quality temporal graph and thus fills the gap between the temporal-spatial correlations for traffic graph, which includes (i) a novel approach to construct temporal graph based on temporal-spatial similarity from traffic graphs, which is much more accurate on measured similarity of time series claimed by previous methods; (ii) an advanced spatial-temporal embedding model to exploit spatial-temporal dependencies by leveraging specific arrangements of temporal and spatial graphs; and (iii) an effective framework that gasps extensive spatial-temporal dependencies in the long-term by mixing multi-layer graph convolution with dilated convolution to understand wide-range spatial-temporal features. Extensive evaluations validate STEGNN by applying it to real-world traffic graphs and indicate that STEGNN outperforms state-of-the-art solutions with much more accurate forecasting of road networks.