摘要:
Disclosed is a data synchronization service for use in a peer-to-peer computing environment. Selected data objects are copied onto selected computing devices. A service running on each device monitors data objects for changes. When a change is detected, the service sends a change notification to the other devices so that they can update their copies of the data object. A user can access a data object from any device, knowing that he will retrieve the latest version of the data object. Instead of incurring the costs of storing a large file on every device, a user “ghosts” the file on some devices. A ghosting device stores only metadata about the file rather than the entire file. The user accesses the file through the ghost: access requests are sent to a device that holds the actual contents, and those contents are presented to the user as if they were stored locally.
摘要:
An efficient and layered synchronization protocol for database systems is disclosed. A mechanism is provided for efficient synchronization of data between storage systems such as relational databases, object stores, etc. Synchronization capabilities may be defined and grouped into several levels that support specific scenarios. The levels may be defined in increasing order of capabilities. Such a synchronization protocol may be designed to work over communication protocols, such as HTTP, for example, between mobile devices and servers. The synchronization protocol may be an XML-based protocol that includes an envelope for handling extensibility and modularity and a body for representing data and metadata within the envelope.