Abstract: A system is disclosed for synchronizing partially-replicated collections while keeping synchronization overhead low by using the concept of item-set knowledge. Item-set knowledge uses knowledge fragments, which associate knowledge vectors with item-sets. An item-set consists of an explicitly represented list of items. In a partial replica, this item set may be the items known to a replica within which a filter is applied limiting the items known to some subset of the overall items in the collection.

Abstract: A system is disclosed for recovery from a compromise of a replica in a weakly-consistent distributed collection. The system employs a collection manager for revoking a compromised replica, and one or more archival replicas for storing time-stamped versions. Upon a compromise, versions tainted by the compromised replica may be expunged from the collection. Thereafter, versions determined to be unaffected by the compromise may be returned to the collection using the time-stamped versions stored in the one or more archival replicas.

Abstract: Methods for enabling multi-master synchronization of particular sets of data using filters. In a synchronization request, data including knowledge and filters may be supplied. A response may comprise data including changes that are identified by the filter and that have versions that are not known by the requestor.

Abstract: An exercise system includes an elastic cord assembly including an elastic and plugs. The elastic has a first and second end and a stretch between the first and second ends. One of the plugs is inserted into the first end and another one of the plugs is inserted into the second end. At least one strap assembly is slidably attached to the elastic cord assembly. The strap assembly includes a block having an aperture formed from one side to another side of the block forming an unbroken wall through the block. The strap assembly also includes a strap connected to the block in a manner that forms a loop in the strap. The plugs retain the strap assembly on the stretch of the elastic cord assembly between the first and second ends.

Abstract: Various embodiments of the present invention are directed to systems and method for detecting conflicts and applying conflict resolutions during manual and automatic conflict resolution operations. Several embodiments are directed to preventing both: (a) non-convergence of conflict resolutions, where partners can end up in a divergent steady state (i.e. have different data in the absence of outstanding conflicts); and (b) a non-terminating ping-pong of conflict resolutions between partners (which can occur with certain inefficient solutions that continuously update metadata for each conflict resolution without end). Certain specific embodiments of the present invention are directed to a method for maintaining knowledge that guarantees convergence of data, even when different partners apply different conflict resolutions.

Abstract: Systems and methods for replicating replicas in a sync community. Each replica in the sync community stores knowledge that represents changes the replica is aware of. Because each replica has its own knowledge, each replica does not need to know how many replicas are in the sync community or the topology of the sync community. By sending the knowledge with a request for changes, a replicating replica can enumerate the changes to replicate by comparing its knowledge with the received knowledge. After replication, the knowledge is updated. Knowledge may also include made-with-knowledge change IDs that permit each resolution to identify what a replica was aware of when a particular change was made. The made-with-knowledge values are used to detect conflicts during replication.

Abstract: A protocol for replicating replicas in a sync community. Each replica maintains a knowledge that represents changes that the replica is aware of. Each replica does not typically maintain knowledge about other replicas. The protocol includes messages that include knowledge about changes on the various replicas. Using the knowledge, the replicas can enumerate changes and send the changes using asynchronous messages that do not need to be received in any particular order. The protocol enables filters to ensure that a valid replication is possible using a minimum knowledge argument. The protocol also enables replicas to partially replicate using filtered knowledge.