Propeller: A Scalable Real-Time File-Search Service in Distributed Systems

File-search service is a valuable facility to accelerate many analytics applications, because it can drastically reduce the scale of the input data. The main challenge facing the design of large-scale and accurate file-search services is how to support real-time indexing in an efficient and scalable way. To address this challenge, we propose a distributed file-search service, called Propeller, which utilizes a special file-access pattern, called access-causality, to partition file-indices in order to expose substantial access locality and parallelism to accelerate the file-indexing process. The extensive evaluations of Propeller show that it is real-time in file-indexing operations, accurate in file-search results, and scalable in large datasets. It achieves significantly better file-indexing and file-search performance (up to 250x) than a centralized solution (MySQL) and much higher accuracy and substantially lower query latency (up to 22x) than a state-of-the-art desktop search engine (Spotlight).