DIRAQ: scalable in situ data- and resource-aware indexing for optimized query performance

作者:Lakshminarasimhan Sriram; Zou Xiaocheng; Boyuka David A II; Pendse Saurabh V; Jenkins John; Vishwanath Venkatram; Papka Michael E; Klasky Scott; Samatova Nagiza F*
来源:Cluster Computing, 2014, 17(4): 1101-1119.
DOI:10.1007/s10586-014-0358-z

摘要

Scientific data analytics in high-performance computing environments has been evolving along with the advancement of computing capabilities. With the onset of exascale computing, the increasing gap between compute performance and I/O bandwidth has rendered the traditional post-simulation processing a tedious process. Despite the challenges due to increased data production, there exists an opportunity to benefit from %26quot;cheap%26quot; computing power to perform query-driven exploration and visualization during simulation time. To accelerate such analyses, applications traditionally augment, post-simulation, raw data with large indexes, which are then repeatedly utilized for data exploration. However, the generation of current state-of-the-art indexes involves a compute- and memory-intensive processing, thus rendering them inapplicable in an in situ context. In this paper we propose DIRAQ, a parallel in situ, in network data encoding and reorganization technique that enables the transformation of simulation output into a query-efficient form, with negligible runtime overhead to the simulation run. DIRAQ%26apos;s effective core-local, precision-based encoding approach incorporates an embedded compressed index that is 3-6 smaller than current state-of-the-art indexing schemes. Its data-aware index adjustmentation improves performance of group-level index layout creation by up to 35 % and reduces the size of the generated index by up to 27 %. Moreover, DIRAQ%26apos;s in network index merging strategy enables the creation of aggregated indexes that speed up spatial-context query responses by up to versus alternative techniques. DIRAQ%26apos;s topology-, data-, and memory-aware aggregation strategy results in efficient I/O and yields overall end-to-end encoding and I/O time that is less than that required to write the raw data with MPI collective I/O.

  • 出版日期2014-12
  • 单位IBM