Pastiche: decentralized, low-cost backup using untrusted, Internet storage

Опубликовано 6 сентября 2016, 5:27

The cost and inconvenience of backup are unavoidable and often prohibitive. Large-scale solutions require aggregation of substantial demand to justify the costs of managing a large, centralized repository. Small-scale solutions require significant administrative effort by the end user. Pastiche is a low-cost, administration-free backup service that eases this tension. Pastiche copies users' backup state into a decentralized, peer-to-peer storage pool composed of volunteered, excess disk space. Each node in the collective is independent, untrusted, and unreliable. Pastiche replicates data at multiple sites so that at least one copy of the data is available at all times with very high probability. This talk will focus on two of the biggest challenges faced by Pastiche: the bandwidth required to create replicas and the incentives needed to encourage participants to contribute storage. Pastiche reduces bandwidth consumption by choosing replica sites based on the amount of overlapping inter-disk data. To bind consumption to contribution, Pastiche imposes a tit-for-tat exchange protocol and exploits cyclic demand among peers to allocate storage.