Abstract: A method for execution by a dispersed storage and task (DST) processing unit includes generating contention level data by evaluating an update contention level in response to determining to update an entry of a node of a dispersed hierarchical index. The update of the node is executed when the contention level data indicates that the update contention level is favorable. An index update request is generated for transmission to an index update unit via a network when the contention level data indicates that the update contention level is unfavorable.

Abstract: A method includes determining, by a computing device, to change a node of a hierarchical index structure. The method further includes determining, by the computing device, whether one or more other computing devices are attempting to change the node. The method further includes, when yes, determining, by the computing device and/or the other computing device(s), to use a delegate device to process multiple change requests to the node. The method further includes, when determined to use the delegate device, sending, by the computing device, a message to the delegate device requesting the delegate device to process the change to the node. The method further includes coordinating, by the delegate device, requested changes to the node by the computing device and the other computing device(s). The method further includes updating, by the delegate device, the node in accordance with the coordinating of the requested changes.

Abstract: A method includes identifying, by a computing device of a dispersed storage network (DSN), a delegate device of a plurality of delegate devices of the DSN for processing a change to a node of a plurality of nodes of a hierarchical index structure. The method further includes sending, by the computing device, a change type specific request to the delegate device regarding the change to the node. The method further includes determining, by the delegate device, whether the delegate device is responsible for executing the change type specific request. When the delegate device is responsible for executing the change type specific request, the method further includes sending, by the delegate device, a response message to the computing device indicating that the delegate device is responsible for executing the change type specific request. The method further includes executing, by the delegate device, the change type specific request.

Abstract: A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method begins by, receiving a write data object request and writing and committing the data object as a set of encoded data slices into DSN memory. The method continues by writing and committing an index consistency write-intent to DSN memory. The method continues by writing metadata of the data object to DSN memory. The method continues by write and committing an index entry to DSN memory. The method continues, during a finalization of the index consistency write-intent, by executing the index consistency write-intent to ensure consistency between the metadata of the data object and metadata located in the index entry.

Abstract: A method includes identifying a fallback delegate device of a plurality of delegate devices for changing one or more nodes of a plurality of nodes of a hierarchical index structure, where a primary delegate device of the plurality of delegate devices is responsible for changing the one or more nodes and where each delegate device of a plurality of delegate devices is assigned an individual global namespace address that is partially based on a location within the DSN. The method further includes determining to process a change to a node of the one or more nodes using the fallback delegate device.

Abstract: A method includes determining that a primary delegate device is unavailable. The method continues by identifying a fallback delegate device for changing a node of a hierarchical index structure using a deterministic function. The deterministic function includes performing a first modification of global namespace address of the unavailable primary delegate device to produce a first modified address identifier. The deterministic function further includes determining whether another delegate device of the plurality of delegate devices has a global namespace address corresponding to the first modified address identifier. When the global namespace address of other delegate device corresponds to the first modified address identifier, the method further includes processing a change to a node of the one or more nodes via the other delegate device as the fallback delegate device.

Abstract: A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method begins by, receiving a write data object request and writing and committing the data object as a set of encoded data slices into DSN memory. The method continues by writing and committing an index consistency write-intent to DSN memory. The method continues by writing metadata of the data object to DSN memory. The method continues by write and committing an index entry to DSN memory. The method continues, during a finalization of the index consistency write-intent, by executing the index consistency write-intent to ensure consistency between the metadata of the data object and metadata located in the index entry.

Abstract: A method for execution by a dispersed storage and task (DST) processing unit includes generating contention level data by evaluating an update contention level in response to determining to update an entry of a node of a dispersed hierarchical index. The update of the node is executed when the contention level data indicates that the update contention level is favorable. An index update request is generated for transmission to an index update unit via a network when the contention level data indicates that the update contention level is unfavorable.

Abstract: A method includes temporarily storing, by a computing device tasks in a task queue to produce queued tasks. The method further includes identifying a task of the queued tasks for execution. The method further includes partitioning the task into a plurality of partial tasks. The method further includes sending partial task execution requests to at least some of the set of storage units. The method further includes transferring the task from the task queue to a task in process index and establishing an expiration time. When a partial task of the plurality of partial tasks has not been completed prior to the expiration time, the method further includes transferring the task from the task in process index to the task queue indicating that the task was not completed prior to the expiration time and re-queuing execution of at least a portion of the task.

Abstract: A method includes determining that a primary delegate device is unavailable. The method continues by identifying a fallback delegate device for changing a node of a hierarchical index structure using a deterministic function. The deterministic function includes performing a first modification of global namespace address of the unavailable primary delegate device to produce a first modified address identifier. The deterministic function further includes determining whether another delegate device of the plurality of delegate devices has a global namespace address corresponding to the first modified address identifier. When the global namespace address of other delegate device corresponds to the first modified address identifier, the method further includes processing a change to a node of the one or more nodes via the other delegate device as the fallback delegate device.

Abstract: A method includes identifying, by a computing device of a dispersed storage network (DSN), a delegate device of a plurality of delegate devices of the DSN for processing a change to a node of a plurality of nodes of a hierarchical index structure. The method further includes sending, by the computing device, a change type specific request to the delegate device regarding the change to the node. The method further includes determining, by the delegate device, whether the delegate device is responsible for executing the change type specific request. When the delegate device is responsible for executing the change type specific request, the method further includes sending, by the delegate device, a response message to the computing device indicating that the delegate device is responsible for executing the change type specific request. The method further includes executing, by the delegate device, the change type specific request.

Abstract: A method includes determining, by a computing device, to change a node of a hierarchical index structure. The method further includes determining, by the computing device, whether one or more other computing devices are attempting to change the node. The method further includes, when yes, determining, by the computing device and/or the other computing device(s), to use a delegate device to process multiple change requests to the node. The method further includes, when determined to use the delegate device, sending, by the computing device, a message to the delegate device requesting the delegate device to process the change to the node. The method further includes coordinating, by the delegate device, requested changes to the node by the computing device and the other computing device(s). The method further includes updating, by the delegate device, the node in accordance with the coordinating of the requested changes.

Abstract: A method to assign delegate devices for updating a hierarchical index structure includes determining a number of delegate devices to assign for updating the hierarchical index structure, wherein the hierarchical index structure is a self-balancing structure. The method further includes determining a node layer of the hierarchical index structure that has at least an equivalent number of nodes as the number of delegate devices. The method further includes, for the node layer, assigning each delegate device of the number of delegate devices a unique one or more nodes of the node layer and corresponding child nodes thereof. The method further includes generating a list of delegate device responsibilities based on the assigning.