Title
DIRAQ: scalable in situ data- and resource-aware indexing for optimized query performance
Abstract
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 "cheap" 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's effective core-local, precision-based encoding approach incorporates an embedded compressed index that is 3---6 $$\times $$ 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's in network index merging strategy enables the creation of aggregated indexes that speed up spatial-context query responses by up to $$10\times $$ 10 versus alternative techniques. DIRAQ'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.
Year
DOI
Venue
2014
10.1007/s10586-014-0358-z
Cluster Computing
Keywords
Field
DocType
Exascale computing,Indexing,Query processing,Compression
Exascale computing,Data analysis,Computer science,Visualization,Search engine indexing,Real-time computing,Rendering (computer graphics),Scalability,Speedup,Encoding (memory)
Journal
Volume
Issue
ISSN
17
4
1386-7857
Citations 
PageRank 
References 
3
0.37
27
Authors
9
Name
Order
Citations
PageRank
Sriram Lakshminarasimhan118710.01
Xiaocheng Zou2645.90
David A. Boyuka II3825.52
Saurabh V. Pendse4483.33
John Jenkins5566.72
Venkatram Vishwanath650747.27
Michael E. Papka7953138.69
Scott Klasky8154799.00
Nagiza F. Samatova986174.04