Temporal motif mining is the task of finding the occurrences of subgraph patterns within a large input temporal graph that obey the specified structural and temporal constraints. Despite its utility in several critical application domains that demand high performance (e.g., detecting fraud in financial transaction graphs), the performance of existing software is limited on commercial hardware platforms, in that it runs for tens of hours. This paper presents Everest - a system that efficiently maps the workload of mining (supports both enumeration and counting) temporal motifs to the highly parallel GPU architecture. In particular, using an input temporal graph and a more expressive user-defined temporal motif query definition compared to prior works, Everest generates an execution plan and runtime primitives that optimize the workload execution by exploiting the high compute throughput of a GPU. Everest generates motif-specific mining code to reduce long-latency memory accesses and frequent thread divergence operations. Everest incorporates novel low-cost runtime mechanisms to enable load balancing to improve GPU hardware utilization. To support large graphs that do not fit on GPU memory, Everest also supports multi-GPU execution by intelligently partitioning the edge list that prevents inter-GPU communication. Everest hides the implementation complexity of presented optimizations away from the targeted system user for better usability. Our evaluation shows that, using proposed optimizations, Everest improves the performance of a baseline GPU implementation by 19x, on average.

翻译：摘要：时序子图模式挖掘旨在从大规模输入时序图中，找出满足指定结构约束与时间约束的子图模式的出现实例。尽管该技术在多个对高性能有严苛要求的关键应用领域（例如金融交易图中的欺诈检测）具有实用价值，现有软件在商用硬件平台上的性能仍十分有限，运行时长可达数十小时。本文提出Everest系统，该系统将时序子图模式的挖掘工作（支持枚举与计数两种模式）高效映射至高度并行的GPU架构。具体而言，相比现有工作，Everest利用输入时序图及更具表达力的用户自定义时序子图模式查询定义，生成执行计划与运行时原语，通过发挥GPU的高计算吞吐量来优化工作负载执行。Everest生成模式专属的挖掘代码，以减少长延迟内存访问与频繁的线程发散操作，并引入新型低开销运行时机制实现负载均衡，提升GPU硬件利用率。为支持无法完全容纳于GPU内存的大规模图，Everest通过智能划分边列表实现多GPU执行，避免GPU间通信。此外，Everest将所有优化方案的实现复杂性对目标系统用户透明，以提高易用性。实验评估表明，采用所提优化后，Everest将基线GPU实现的性能平均提升了19倍。