Archpipe: Fast and Flexible Pipelined Erasure-coded Archival Scheme for Heterogeneous Networks

Abstract

Erasure-coded archival converts the redundancy mechanism of low access-frequency data from replication to erasure coding for balancing access performance and storage efficiency. A variety of pipelined schemes are designed to speed up the archival operation, however they neglect such three factors as heterogeneous network, under-utilization of replica resources and tight coupling with underlying platforms which restrict or even negate the performance gains. In this paper, we propose Archpipe, a fast and flexible pipelined erasure-coded archival scheme. It exhibits three distinct features: 1) heterogeneous network awareness, for a single-pipelined construction, sufficient-bandwidth links are given high scheduling priority to avoid network congestion, while considering locality to reducing network transmissions; 2) parallel encoding, the unused replica resources are exploited to adaptively construct multiple pipelines for each stripe based on the single-pipelined algorithm, thereby enabling parity blocks to be encoded in parallel; 3) loose coupling, it does not rely on specific block placement policies and stripe construction algorithms. Experimental results indicate that, Archpipe can be seamlessly integrated with common distributed storage systems, and it improves the erasure-coded archival performance by 3.6 ∼ 4.7× and 1.3 ∼ 2.6× in on-disk and in-memory scenarios, respectively.