d-sptf · research · also Distributed Shortest-Positioning Time First

D-SPTF

D-SPTF is a decentralized storage protocol that coordinates replicated read queues using cache hits and predicted disk positioning times.

Related Observatory article: D-SPTF on hesela.com

A cache miss is forwarded to replica holders. Claims remove competing queued reads; concurrent bids prefer shorter positioning time, then lower brick ID. Pre-scheduling provides a short coordination window. [1]

Delayed or lost claims can still cause duplicate work. A claimant that fails before replying requires client timeout and retry. This is not an exactly-once guarantee. [1]

The ASPLOS 2004 evaluation uses DiskSim, not a deployed fleet. Modern SSD performance is not established. [1]

Relations

related

Adaptive replica selection, Tied request, Seek time, I/O scheduler

Citations

1. Lumb, Golding and Ganger. D-SPTF: Decentralized Request Distribution in Brick-based Storage Systems. ASPLOS 2004, sections 3-5. (accessed 2026-11-09)

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