Using reconciliation to share files between occasionally connected computers

Abstract

Future large distributed systems will be made by interconnecting highly autonomous subsystems, rather than by building ever more elaborate complexes which attempt to provide a single system image transparent to the user. The work described here explores the implications of this in the context of file sharing using occasional reconciliation.

Flockfs, a moderated group authoring system for wireless workgroups

“…In a work-in-progress report, Howard et al [14] introduce the notion of maintaining multiple autonomous versions that reconcile rarely with no single authoritative version. flockfs also maintains n different versions which are reconciled using the moderation option.…”

“…Hence, we designed flockfs to address this limitation. As articulated by Howard et al [14], flockfs does not maintain a single shared copy. Each user is responsible for updating and maintaining their own copy.…”

The Bayou Architecture: Support for Data Sharing Among Mobile Users

“…This process is often called "reconciliation" when used to synchronize file systems [11] [13]. Anti-entropy ensures that all copies of a database are converging towards the same state and will eventually converge to identical states if there are no new updates.…”

“…Version vectors, as developed for Locus [21], or simple timestamps are popularly used to detect write-write conflicts [11] [13) [14)[23]. Read-write conflicts can be detected by recording and later checking an application's read-set [8].…”