摘要:
Aspects of the subject matter described herein relate to resource replication systems. In aspects, a mechanism is described that detects when local resources are stale. Local resources may be stale when the time between a last successful synchronization activity and a current time exceeds a staleness value. If the local resources are determined to be stale, the local member may refrain from certain synchronization activities until the local member is allowed to resume these certain synchronization activities. If the local resources are not stale, additional synchronization activities including synchronizing resources between the member and an upstream or downstream partner may be performed.
摘要:
Aspects of the subject matter described herein relate to shutdown recovery for resource replication systems. In aspects, a mechanism is described in which a machine having replicated data thereon can recover from a dirty shutdown. First, the machine determines whether a dirty shutdown has occurred. If so, the machine automatically performs shutdown recovery by causing resource metadata stored by the machine to be consistent with resource data stored by the machine. This may involve fixing the resource metadata for updates to the resource data that were not flushed to disk or may involve deleting the resource metadata and restoring it from another machine replicating the data.
摘要:
Aspects of the subject matter described herein relate to replicating resources across machines participating in a replica set. In aspects, a downstream machine requests that an upstream machine notify the downstream machine when updates to resources of the replica set occur. When such updates occur, the upstream machine notifies the downstream machine. In response thereto, the downstream machine requests resource meta-data and may include a limit as to how much resource meta-data may be sent. The upstream machine responds with the requested resource meta-data. Thereafter, the downstream machine determines which data associated with the updated resources to request and requests such data.
摘要:
Aspects of the subject matter described herein relate to replicating initial content in resource replication systems. In aspects, each member participating in a replica group obtains a content set state from a directory service. The content set state indicates whether the member is allowed to synchronize resources with another member participating in the replica group. If the member is designated as a primary member, the member may replicate out resources to its downstream partners. If a member is not designated as a primary member, the member may not replicate out resources to its downstream partners until it has successfully synchronized resources with an upstream partner. Fence values may be set which control which resources win (and are replicated out) during synchronization.
摘要:
Aspects of the subject matter described herein relate to resource replication systems. In aspects, a mechanism is described that maintains replicated resources on a slave member that participates in a replica group. The slave member detects that a local resource has been updated locally. If the resource was created locally in the update, the slave member deletes the local resource. Otherwise, the slave member determines an upstream partner from which to install a replacement resource and then installs the replacement resource. In aspects, this behavior undoes local updates to local resources that occur on the slave member.
摘要:
A computing device has a file stored on a storage volume by a file system and accessed through such file system. The file is defined to include data and metadata relating to the data, and at least a portion of the data of the file is removed from the file and stored at an alternate location such that the data does not occupy substantially any space on the volume and the file is in a reduced, ghosted form. The ghosted file is reconstituted for use by retrieving the data from the alternate location and associating such retrieved data with such ghosted file to form the reconstituted file.
摘要:
Various embodiments introduce the notion of a replication entity which implements a highly scalable file replication system. In one embodiment, the replication entity resides in the form of a scalable replication service. In at least some embodiments, the replication service provides a “drive in the sky” facility that can be used by individuals, such as subscribers, to synchronize their individual machines, such that their files are automatically replicated to a safe and always-on location. Alternatively or additionally, individuals such as subscribers can also access their files via a web-based interface when they are away from their machines.
摘要:
The present invention provides a method for chunking an object. The method is arranged to provide efficient chunking of objects such that objects can be efficiently updated between a remote machine and a local machine over a network. The chunking algorithm is applicable in networked application such as file synchronization using remote differential compression (RDC) techniques. The chunking algorithm provides enhanced efficiencies by locating chunk boundaries around local maxima.
摘要:
Peer devices register with a resource locator service so that the peer devices can be uniquely identified in a networking environment. An addressing scheme addresses a peer resource in the networking environment based on the unique identifier of a peer device that is a master publisher of the resource. Based on the addressing scheme, the resource locator service can track the location of the master publisher of the resource as well as additional locations of peer devices that have cached the resource and made it available. In various embodiments, the resource locator service can service requests for peer resources by providing a list of locations where the resource is expected to be available or, in the case of non-compatible requester, provide access to the resource itself.
摘要:
A method and system for controlling which content gets precedence and is replicated. A replica set is comprised of a set of resources. Each resource is associated with resource data and resource meta-data. For files-based systems, resource data includes file contents and attributes, while resource meta-data includes additional attributes that are relevant for negotiating synchronization during replication. An extra field called a “fence value” is added to the meta-data associated with each resource. During synchronization, first fence values are compared. The resource with the highest fence value includes the content that is controlling and replicated. If fence values are equal (and greater than a particular value), the controlling resource is determined based on other meta-data.