| 摘要 |
A directory includes information about various systems (e.g., applications, processes, tasks, objects, services) and data, and may include data ownership information. The directory may define existing systems, corresponding locations by address, and corresponding semantic names. The directory may also specify the role of each system, e.g., a consumer or provider role. The directory may also define a scope of data a provider system can provide. As such, the directory may also include information about whether and how such data is being replicated. When a user requests data, a service may, based on the directory, determine and select an appropriate provider system for the data. The service may further create a subscription process to provide the user a local cache of the requested data. With such directory information, a service can provide data access services that integrate subscription processes. |
