Archive for the ‘Synchronization’ Category

Synchronizer Based on Operational Transformation…

Monday, July 28th, 2014

Synchronizer Based on Operational Transformation for P2P Environments by Michelle Cart and Jean Ferrié


Reconciling divergent copies is a common problem encountered in distributed or mobile systems, asynchronous collaborative groupware, concurrent engineering, software configuration management, version control systems and personal work involving several mobile computing devices. Synchronizers provide a solution by enabling two divergent copies of the same object to be reconciled. Unfortunately, a master copy is generally required before they can be used for reconciling n copies, otherwise copy convergence will not be achieved. This paper presents the principles and algorithm of a Synchronizer which provides the means to reconcile n copies, without discriminating in favour of any particular copy. Copies can be modified (concurrently or not) on different sites and the Synchronizer we propose enables them to be reconciled pairwise, at any time, regardless of the pair, while achieving convergence of all copies. For this purpose, it uses the history of operations executed on each copy and Operational Transformations. It does not require a centralised or ordering (timestamp, state vector, etc.) mechanism. Its main advantage is thus to enable free and lazy propagation of copy updates while ensuring their convergence – it is particularly suitable for P2P environments in which no copy should be favoured.

Not the oldest work on operational transformations, 2007, nor the most recent.

Certainly of interest for distributed topic maps as well as other change tracking applications.

I first saw this in a tweet by onepaperperday.

ResourceSync Framework Specification

Monday, February 11th, 2013

NISO and OAI Release Draft for Comments of ResourceSync Framework Specification

From the post:

NISO and the Open Archives Initiative (OAI) announce the release of a beta draft for comments of the ResourceSync Framework Specification for the web consisting of various capabilities that allow third-party systems to remain synchronized with a server’s evolving resources. The ResourceSync joint project, funded with support from the Alfred P. Sloan Foundation and the JISC, was initiated to develop a new open standard on the real-time synchronization of Web resources.

Increasingly, large-scale digital collections are available from multiple hosting locations, are cached at multiple servers, and leveraged by several services. This proliferation of replicated copies of works or data on the Internet has created an increasingly challenging problem of keeping the repositories’ holdings and the services that leverage them up-to-date and accurate. The ResourceSync draft specification introduces a range of easy to implement capabilities that a server may support in order to enable remote systems to remain more tightly in step with its evolving resources.

The draft specification is available on the OAI website at: Comments on the draft can be posted on the public discussion forum at:!forum/resourcesync.

For more on the ResourceSync Framework, see the article in the January/February 2013 issue of D-Lib.

For those interested in synchronization of resources. Say from or to topic maps.