Eventually consistent storage and transactions in cloud based environment

A system, comprising:

• a general purpose computing device;
• and
• a computer program comprising program modules executable by the computing device, wherein the computing device is directed by the program modules of the computer program to:
• provide one or more fork-join models that use a conflict resolution policy, which does not include a causally consistent partial order or timestamp evaluation, for applying updates to a primary revision of data shared between a plurality of computing devices connected to a networking environment;
• maintain the primary revision on one or more of the computing devices acting as a primary host, said primary revision representing a local revision held by the primary host;
• initiate one or more forks of the primary revision to one or more computing devices acting as any of clients and secondary hosts to create one or more nested levels of forked revisions, each forked revision stored as a local revision on the computing devices receiving those forked revisions;
• perform one or more update operations on any local revision to create corresponding updated local revisions;
• and
• provide eventually consistent transactions by performing the following case-based actions while the data is being shared:
• if the client updates its local revision and a new revision is not currently expected by the client from any host, sending a copy of that client's updated local revision to one or more of the hosts, and locally forking a new copy of the updated local revision for continued local use by the client,
• if the new revision has been received by the client from any host, using one or more of the fork-join models to join the local revision into the new revision received from the host to create a new local revision for that client, and
• if the new revision expected from any host is not currently available to the client, preventing that client from joining or forking its local revision, and for any copy of the client's local revision sent to one or more hosts, joining that copy to the primary revision in accordance with one or more of the fork-join models to update the primary revision maintained by the primary host.

A computer-readable storage hardware device having computer executable instructions stored therein, said instructions causing a computing device to execute a method comprising:

• providing one or more fork-join models that provide a pre-defined conflict resolution policy, defined by a cloud data type, for applying updates to a primary revision of data shared between a plurality of computing devices connected to a networking environment;
• maintaining a primary revision of the shared data on one or more of the computing devices acting as a primary host, said primary revision representing a local revision held by the primary host;
• initiating one or more forks of the primary revision to one or more computing devices acting as any of clients and secondary hosts to create one or more nested levels of forked revisions, each forked revision stored as a local revision on the computing devices receiving those forked revisions;
• performing one or more update operations on any local revision to create corresponding updated local revisions;
• and
• providing eventually consistent transactions by joining one or more updated local revisions received by any particular host into the local revision of the particular host, and applying all update operations that were performed on the received updated local revisions, in the time between the fork of the primary revision to the corresponding computing device and the join of the corresponding updated local revision to the local revision of the particular host in accordance with the conflict-resolution policy.