Key Concepts in the Sync Framework

Applies to: SharePoint Foundation 2010

The Microsoft Sync Framework employs several key concepts. Following are brief descriptions of these key concepts and the special vocabulary that describes them.

Key Synchronization Concepts and Terms


The process of segmenting data into packets, as opposed to initiating a single transfer operation of an entire data store.


A service, application, or device that integrates with the Microsoft Sync Framework and receives synchronization updates from a server.

Clock vector

A list of synchronization versions that is ordered by the replica key.


A set of ID/value pairs that track the version state of a specified synchronization item (or replica). Knowledge is maintained as metadata, which individual replicas must update and maintain. Knowledge is portable and can be understood by any peer. Furthermore, each replica maintains its own knowledge.


Clients that make changes independently.


A set of continuous item identifiers to which a clock vector applies. A range is demarcated by a start point, and end point; the clock vector represents all IDs that are included between the start and end points.


Collection or range of items to be synchronized, along with associated synchronization metadata. A unit of synchronization. This term is sometimes used interchangeably with the term "store."

Replica key

A unique identifier for a specified replica.

Sync Provider (Provider)

A collection of application programming interfaces (APIs) defined by the Sync Framework that are implemented by a replica and which enable integration of the Sync Framework into the sync architecture.

Sync Scope

The range or set of individual objects that undergo synchronization in a specified synchronization operation.

Sync Version

Synchronization metadata that is associated with a specific item identifier/change unit identifier pair. The sync version consists of the replica key and an unsigned number, which is called the tick count.

Tick Count

A numerical counter of change instances for a specified item. The largest tick count for a specified item version represents the most recent synchronization state. The tick count is maintained as metadata to track version information for a given replica. Sometimes also referred to as the "change log number."

See Also


Introducing the Microsoft Sync Framework for SharePoint