Handling Big Data in Astronomy and Astrophysics: Rich Structured Queries on Replicated Cloud Data with XtreemFS
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With recent observational instruments and survey campaigns in astrophysics, efficient analysis of big structured data becomes more and more relevant. While providing good query expressiveness and data analysis capabilities through SQL, off-the-shelf RDBMS are yet not well prepared to handle high volume scientific data distributed across several nodes, neither for fast data ingest nor for fast spatial queries. Our SQL query parser and job manager performs query reformulation to spread queries to data nodes, gathering outputs on a head node and providing them again to the shards for subsequent processing steps. We combine this data analysis architecture with the cloud data storage component XtreemFS for automatic data replication to improve the availability and access latency. With our solution we perform rich structured data analysis expressed using SQL on large amounts of structured astrophysical data distributed across numerous storage nodes in parallel. The cloud storage virtualization with XtreemFS provides elasticity and reproducibility of scientific analysis tasks through its snapshot capability.
KeywordsFile System Cloud Storage Head Node Dark Matter Halo Spatial Query
Part of the work on the RDBMS is funded by “Virtuelles Datenzentum (VDZ)”, BMBF grant 05A09BAB. We thank K. Riebe and J. Klar (AIP) for critical discussions and suggestions.
The XtreemFS development was partly funded by the EU projects XtreemOS (2006–2010) and Contrail (2010–2013) and by the German BMBF projects MoSGrid (2009–2012) and VDZ (2010–2012). We thank the XtreemFS team for the design and implementation of XtreemFS which, with its unique feature set, became a perfect tool for research on distributed data management.
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