Abstract: A method includes determining, by a computing device of a dispersed storage network (DSN), routing path performance information of a set of routing paths with respect to a set of storage units of the DSN. The method further includes adjusting a pillar width to decode threshold ratio of a dispersed storage error encoding function when the routing path performance information deviates from a performance threshold. The performance threshold includes a first error rate threshold and a second error rate threshold. The method further includes dispersed storage error encoding a data object using the adjusted pillar width to decode threshold ratio to produce a plurality of sets of encoded data slices. The method further includes sending the plurality of sets of encoded data slices to the set of storage units via the set of routing paths for storage therein.

Abstract: Methods and apparatus for isolating the introduction of software defects in a dispersed storage network (DSN) are disclosed. In various embodiments, a search strategy is employed whereby after identifying a test failure in a current version of the memory software code, a sequence of interim versions of the code between the current version of the memory software code and a previous successfully tested version of the code is determined. A first version of the memory software code is selected from the sequence of interim versions (e.g., from the middle of or approximately in the middle of the sequence) and tested. When testing of the first version does not result in a test failure, a second version of the memory software code is tested, the second version selected from a sub-sequence of the sequence of interim versions between the first version of the code and the current version of the code.

Abstract: A method includes determining, by a storage unit, to place a pointer in a hash table that is stored in local memory of the storage unit. The method further includes executing, by the storage unit, a hash function on addressing information relating to the pointer to produce a hash resultant. The method further includes executing, by the storage unit, a second function on related data to the addressing information or to the pointer to produce an auxiliary resultant. The method further includes storing, by the storage unit, the hash resultant and the auxiliary resultant as an entry in the hash table for the pointer, wherein, when a hash collision occurs with respect to the hash resultant, the storage unit utilizes the auxiliary resultant to resolve the hash collision.

Abstract: A method for execution by a compaction management system includes determining observed compaction information based on compaction observed in at least one storage device during an observed timeframe. An estimated compaction rate is generated for a first future timeframe based on the observed compaction information. An updated ingest rate is generated for the first future timeframe based on a current ingest rate and the estimated compaction rate. A first proper subset of a set of data to be written to the at least one storage device is generated based on the updated ingest rate. Storage of the first proper subset in the at least one storage device is facilitated during the first future timeframe. Storage of a remaining proper subset of the set of data in an elastic buffer is facilitated during the first future timeframe, where the elastic buffer utilizes a memory of the compaction management system.

Abstract: A method for processing partial tasks in a distributed storage network (DSN) includes receiving a partial task request message for a DS execution unit, where the partial task request message includes corresponding partial tasks. The method continues by processing each partial task request message in accordance with the processing parameters to produce task request slice groupings, generating slices, such that each message is directed at a corresponding DS execution unit, and the sending the slice groupings and the task request slice groupings to the selected DS execution units for storage therein. The method continues by retrieving at least a decode threshold number of task response slices of one or more task response slice groupings from the DS execution units, decoding the task response slices, retrieving at least a decode threshold number of partial result slices, and decoding the partial results slices and processing the partial results to produce a result.

Abstract: A method for execution by a computing device of a dispersed storage network includes identifying a DSN address for data to be accessed within a DSN. A plurality of storage cohorts associated with the data to be accessed are identified. Ranked scoring information for each storage cohort obtaining ranked scoring information for each storage cohort of the plurality of storage cohorts with regards to the data to be accessed is obtained. A storage cohort of the plurality of storage cohorts is selected based on the ranked scoring information. Slice access requests are issued to a set of storage units of the selected storage cohort for the data to be accessed. Slice access responses received from at least one of the set of storage units of the selected storage cohort are processed.

Abstract: A method begins by determining, by an authenticated device of a dispersed storage network (DSN), whether an access request from a requesting device is affiliated with an anonymous user or an authenticated user. When the requesting device is affiliated with the anonymous user, the method continues by determining, by the authenticated device, status of the anonymous user where the status of the anonymous user includes one of minimal threat, non-minimal threat, and significant threat. The method continues by processing, by the authenticated device, the access request in accordance with the status of the anonymous user.

Abstract: A distributed storage network (DSN) includes a DSN memory and a distributed storage (DS) processing unit. The DS processing unit determines a particular revision of source data for persistence, and generates a protocol message associated with the particular revision of source data. The protocol message is generated based on a balance between durability and persistence associated with the particular revision. The protocol message is transmitted from the DS processing unit to the DSN memory, and indicates to the DSN memory a particular persistence protocol. The DSN memory process data slices corresponding to the particular revision of source data in accordance with the particular persistence protocol.

Abstract: A processing module of a memory storage unit includes an interface configured to interface and communicate with a communication system, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory that is configured to execute the operational instructions to manage data stored using append-only formatting. When the processing module determines that a section of the memory includes invalid data and the amount of invalid data compares unfavorably to a predetermined limit, the processing module determines a rate for execution of a compaction routine for the section of memory, where the rate is based on a proportion, integral and derivative (PID) function that is based on a target usage level of the memory and a current usage level of the memory.

Abstract: A method begins or continues by a computing device of a dispersed storage network (DSN) determining an error with a first write request in a first zone of a plurality of zones of a memory device of a storage unit of DSN, where the first zone includes a first set of sequential blocks that are in a first logical and physical location of the memory device. The method continues with the computing device abandoning pending write requests to the first zone. The method continues with reassigning the first write request to a second zone of the memory device, where the second zone includes a second set of sequential blocks that are in a second logical and physical location of the memory device.

Abstract: A method for execution by a computing device to adjust data storage efficiency of data in a storage network begins by obtaining a data segment for storage in memory of the storage network. The method continues by obtaining access level information regarding the data segment, where the access level information includes an estimated retrieval frequency level for the data segment. The method continues by determining a storage approach for the data segment based on the access level information and processing the data segment based on the storage approach to produce a processed data segment. The method continues by dispersed storage error encoding the processed data segment to produce a set of encoded data slices, where a decode threshold number of encoded data slices is needed to recover the processed data segment. The method continues by sending the set of encoded data slices to the memory for storage therein.

Abstract: A method for execution by a storage unit includes identifying, from a plurality of memory devices of the storage unit, a first memory device that is designated for storage of a first data slice to be written of the storage unit based on determining a slice name of the first data slice compares favorably to a namespace assigned to the first memory device. A function is performed on the slice name of the first data slice to identify a second memory device from the plurality of memory devices of the storage unit for temporary storage the first data slice in response to determining that the first memory device is unavailable and the first data slice is stored in the second memory device in response. The first data slice is migrated to storage in the first memory device in response to determining that the first memory device is available.

Abstract: A method for execution by a storage unit includes identifying, from a plurality of memory devices of the storage unit, a first memory device that is designated for storage of a first data slice to be written of the storage unit based on determining a slice name of the first data slice compares favorably to a namespace assigned to the first memory device. A function is performed on the slice name of the first data slice to identify a second memory device from the plurality of memory devices of the storage unit for temporary storage the first data slice in response to determining that the first memory device is unavailable and the first data slice is stored in the second memory device in response. The first data slice is migrated to storage in the first memory device in response to determining that the first memory device is available.

Abstract: A method for execution by a dispersed storage and task (DST) execution unit includes generating a first compaction object by performing a compaction function on a first previously compacted object and first data slices that compare favorably to a cold access threshold. Storage of the first previously compacted object in a cold memory region is replaced with the first compacted object, and the first data slices are removed from prior storage in different memory regions. A second compacted object is generated by performing the compaction function on a second previously compacted object and second data slices that compare favorably to a hot access threshold. Storage of the second previously compacted object in a hot memory region is replaced with the second compacted object, and the second data slices are removed from prior storage in different memory regions.

Abstract: A method for execution by one or more processing modules of a storage network (SN) begins with the one or more processing modules scanning a storage node of the SN at a predetermined interval to determine whether an erasure encoded data slice (EEDS) of a set of erasure encoded data slices (EEDSs) is corrupt, where the set of erasure encoded data slices (EEDSs) is generated from object data using an erasure error encoding dispersal function. The method continues with the one or more processing modules determining that an EEDS is corrupt and in response, rebuilding the EEDS in place in the storage node.

Abstract: A method for execution by a storage unit includes identifying, from a plurality of memory devices of the storage unit, a first memory device that is designated for storage of a first data slice to be written of the storage unit based on determining a slice name of the first data slice compares favorably to a namespace assigned to the first memory device. A function is performed on the slice name of the first data slice to identify a second memory device from the plurality of memory devices of the storage unit for temporary storage the first data slice in response to determining that the first memory device is unavailable and the first data slice is stored in the second memory device in response. The first data slice is migrated to storage in the first memory device in response to determining that the first memory device is available.

Abstract: A method for execution by a storage unit includes identifying, from a plurality of memory devices of the storage unit, a first memory device that is designated for storage of a first data slice to be written of the storage unit based on determining a slice name of the first data slice compares favorably to a namespace assigned to the first memory device. A function is performed on the slice name of the first data slice to identify a second memory device from the plurality of memory devices of the storage unit for temporary storage the first data slice in response to determining that the first memory device is unavailable and the first data slice is stored in the second memory device in response. The first data slice is migrated to storage in the first memory device in response to determining that the first memory device is available.

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 computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request for an encoded data slice (EDS) associated with a data object. The computing device compares a slice name of the data access request with slice names stored within RAM. When the data access request slice name compares unfavorably with those stored slice names, the computing device transmits an empty data access response that includes no EDS to the other computing device without needing to access a hard disk drive (HDD) that stores EDSs. Alternatively, the computing device transmits a data access response that includes the EDS.

Abstract: A method for execution by a processing system in dispersed storage and task network (DSTN) that includes a processor, includes: identifying a slice name of a slice in error of a set of slices stored in a set of dispersed storage (DS) units; identifying a number of slice errors of the set of slices; generating a queue entry that includes the slice name of the slice in error, a rebuilding task indicator, an identity of the set of slices, and the number of slice errors; identifying a rebuilding queue based on the number of slice errors, wherein the rebuilding queue is associated with one of: the set of DS units or another set of DS units; and facilitating storing the queue entry in the identified rebuilding queue.