Abstract: Methods and systems for consistent reads in a distributed transaction protocol are disclosed. A method includes: receiving, by a computing device, a request to write a revision of a data object in a dispersed storage network (DSN); sending, by the computing device, a proposal with the revision of the data object to a plurality of storage units; receiving, by the computing device, a response to the proposal from each of the plurality of storage units, the response including a proposed minimum timestamp corresponding to the data object; determining, by the computing device, a minimum timestamp for the data object based on the proposed minimum timestamps received from the plurality of storage units; and determining, by the computing device, a version of the data object written in the DSN based on the minimum timestamp.

Abstract: A method, system, and computer program product for implementing indices in a dispersed storage network (dsNet) are provided. The method receives a key-value pair to be stored in a dsNet. The method routes the key and the value within a data source containing a SourceName repository and a data buffer. The key is routed to the SourceName repository and the value is routed to the data buffer. The data source is erasure encoded into a set of data slices having a slice name and a slice buffer. The method stores the set of data slices within the dsNet. The method generates a namespace index with an index entry for the key-value pair. The index entry represents the key-value pair as a SourceName and a data source indicator with the SourceName and the data source indicator being associated with the set of data slices.

Abstract: A method, system, and computer program product for implementing indices in a dispersed storage network (dsNet) are provided. The method receives a key-value pair to be stored in a dsNet. The method routes the key and the value within a data source containing a SourceName repository and a data buffer. The key is routed to the SourceName repository and the value is routed to the data buffer. The data source is erasure encoded into a set of data slices having a slice name and a slice buffer. The method stores the set of data slices within the dsNet. The method generates a namespace index with an index entry for the key-value pair. The index entry represents the key-value pair as a SourceName and a data source indicator with the SourceName and the data source indicator being associated with the set of data slices.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: Methods and systems for consistent reads in a distributed transaction protocol are disclosed. A method includes: receiving, by a computing device, a request to write a revision of a data object in a dispersed storage network (DSN); sending, by the computing device, a proposal with the revision of the data object to a plurality of storage units; receiving, by the computing device, a response to the proposal from each of the plurality of storage units, the response including a proposed minimum timestamp corresponding to the data object; determining, by the computing device, a minimum timestamp for the data object based on the proposed minimum timestamps received from the plurality of storage units; and determining, by the computing device, a version of the data object written in the DSN based on the minimum timestamp.

Abstract: A method begins by a processing module of a dispersed storage network (DSN) determining a fault domain for a portion of the DSN and generating a local redundancy for the fault domain. The method continues with the processing module identifying storage locations available for storing the first local redundancy, selecting storage locations for storing the first local redundancy and continues with the processing module facilitating storage of the local redundancy in the storage locations. Upon detecting a storage failure in the DSN, the method continues with the processing module determining whether the storage failure is associated with the fault domain and in response determining whether the first local redundancy is associated with the first fault domain. In response to determining that the local redundancy is associated with the first fault domain the method continues with the processing module recovering the local redundancy and correcting the storage failure.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: A method includes determining an acceptable site failure number for storing a set of encoded data slices based on available sites and storage units within the available sites. The method further includes determining dispersed storage error encoding parameters based on the acceptable site failure number, wherein the parameters includes a decode threshold number and a total width number. The method further includes encoding, in accordance with the parameters, a data segment of data to produce the set of encoded data slices. The method further includes generating a slice mapping based on the acceptable site failure number, the available sites, and the storage units within the available storage units within the available sites. The method further includes sending, based on the slice mapping, the set of encoded data slices to at least some of the storage units within at least some of the available sites for storage therein.

Abstract: A method begins by a dispersed storage (DS) processing module transmitting a set of write commands for storing a set of encoded data slices in storage units of a dispersed storage network (DSN) and determining whether at least a first threshold number of write responses have been received within a response time period. When the at least the first threshold number of the write responses have been received within the response time period, the method continues with the DS processing module determining whether a total number of responses have been received within another response time period. When the total number of responses have not been received within the other response time period, the method continues with the DS processing module issuing a sub-set of write commit commands corresponding to a response number of encoded data slices for which a response was received.

Abstract: A method begins by a first computing device of a plurality of computing devices accessing a rebuild hierarchical index structure to identify a data object having encoded data slices requiring rebuilding, where the structure includes a plurality of nodes that organizes a plurality of data objects based on a level of need of rebuilding. The method continues with the first computing device utilizing a rebuilding function to rebuild one or more of the identified encoded data slices to be rebuilt to produce one or more rebuilt encoded data slices and sending a write request to memory of a dispersed storage network to store the one or more rebuilt encoded data slices. The method continues with the first or another computing device updating the level of need of rebuilding of the identified data object and updating the rebuild hierarchical index structure based on the updated level of need of rebuilding.

Abstract: A computing device of a dispersed storage network (DSN) includes a memory, interface and a processing module operable to identify an encoded data slice of the set of encoded data slices to produce an identified encoded data slice. The processing module generates a set of first write requests regarding the set of encoded data slices less the identified encoded data slice, and generates a set of second write requests regarding the identified encoded data slice. The set of second write requests include the identified encoded data slice and replications of the identified encoded data slice. The processing module sends the set of first write requests to storage units of the DSN, and sends the set of second write requests to a set of storage units of the DSN, where each storage unit of the set of storage units is sent a corresponding one of the set of second write requests.

Abstract: Methods and apparatus for selection of memory locations for data access operations in a dispersed storage network (DSN) are disclosed. In various embodiments, a dispersed storage (DS) processing module of the DSN receives a DSN access request regarding at least one data segment of a data object. The DS processing module determines a DSN address associated with the DSN access request and performs a scoring function using the DSN address and one or more properties of DSN memory to produce a storage scoring resultant. The storage scoring resultant is utilized to identify a set of storage units of the DSN. A set of access requests is then sent to the set of storage units regarding the DSN access request. The scoring function can include, for example, performing deterministic functions, normalizing functions and ranking functions to produce the storage scoring resultant.

Abstract: In an approach, a processor detects a transmission control protocol disconnection of a first distributed storage unit from a distributed storage network, wherein the distributed storage network comprises a set of distributed storage units. A processor identifies a transaction, wherein: the transaction is not in a final state, the transaction is a first proposal, from the first distributed storage unit, for the set of distributed storage units to store a dataset with a first revision number within the distributed storage network, and the dataset is broken into one or more data pieces to be written on the set of distributed storage units of the distributed storage network that approve the proposal. A processor identifies a timestamp of the transaction. A processor determines a stage the transaction has reached. A processor places the transaction in a final state based on the determined stage the transaction has reached.

Abstract: A method begins by a processing module of a dispersed storage network (DSN) determining a fault domain for a portion of the DSN and generating a local redundancy for the fault domain. The method continues with the processing module identifying storage locations available for storing the first local redundancy, selecting storage locations for storing the first local redundancy and continues with the processing module facilitating storage of the local redundancy in the storage locations. Upon detecting a storage failure in the DSN, the method continues with the processing module determining whether the storage failure is associated with the fault domain and in response determining whether the first local redundancy is associated with the first fault domain. In response to determining that the local redundancy is associated with the first fault domain the method continues with the processing module recovering the local redundancy and correcting the storage failure.

Abstract: A method begins by storage units of a dispersed storage network (DSN) receiving a retrieval request for a data object, where each storage unit stores a unique group of encoded data slices of the data object and a local set of encoded recovery data slices. The method continues with some storage units sending the unique group of encoded data slices to a requesting computing device and with one storage unit sending an encoded recovery data slice to the requesting computing device. The method continues with the requesting computing device identifying an errant unique group encoded data slice, correcting the errant encoded data slice based on received data slices to produce an updated unique group of encoded data slices, and dispersed storage error decoding the updated unique group of encoded data slices and the unique groups of encoded data slices from other storage units to recover the data object.

Abstract: A method includes identifying a data object for retrieval. The data object is encoded in accordance with first encoded parameters and stored as a plurality of sets of encoded data slices in a set of storage units. The method further includes determining whether an access metric regarding the data object exceeds an access threshold. When the access metric is equal to or exceeds the access threshold, the data object is further encoded in accordance with second encoding parameters and stored as a second plurality of sets of encoded data slices in a second set of storage units. The method further includes issuing retrieval requests to the second set of storage units regarding the second plurality of encoded data slices in accordance with a read threshold of the second encoding parameters. The method further includes recovering the data object from the second plurality of encoded data slices.