A storage unit operates by: receiving a write slice request, wherein the write slice request includes a plurality of encoded data slices and wherein the write slice request corresponds to a range; determining whether a write lock conflict exists based on the range; issuing an unfavorable write slice response when the write lock conflict is determined to exist; and when the write lock conflict is determined to not exist: initiating local storage of the plurality of encoded data slices; and issuing a favorable write slice response.

A cluster receives a request to store an object using replication or erasure coding. The cluster writes the object using erasure coding. A manifest is written that includes an indication of erasure coding and a unique identifier for each segment. The cluster returns a unique identifier of the manifest. The cluster receives a request from a client that includes a unique identifier. The cluster determines whether the object has been stored using replication or erasure coding. If using erasure coding, the method reads a manifest. The method identifies segments within the cluster using unique segment identifiers of the manifest. Using these unique segment identifiers, the method reconstructs the object. A persistent storage area of another disk is scanned to find a unique identifier of a failed disk. If using erasure coding, a missing segment previously stored on the disk is identified. The method locates other segments. Missing segments are regenerated.

Technologies for applying a redundancy encoding scheme to segmented portions of a data block include an endpoint computing device communicatively coupled to a destination computing device. The endpoint computing device is configured to divide a block of data into a plurality of data segments as a function of a transmit window size and a redundancy encoding scheme, and generate redundant data usable to reconstruct each of the plurality of data segments. The endpoint computing device is additionally configured to format a series of network packets that each includes a data segment of the plurality of data segments and generated redundant data for at least one other data segment of the plurality of data segments. Further, the endpoint computing device is configured to transport each of the series of network packets to a destination computing device. Other embodiments are described herein.

Certain aspects of the present disclosure relate to techniques and apparatus for improving decoding latency and performance of Polar codes. An exemplary method generally includes generating a codeword by encoding information bits, using a multi-dimensional interpretation of a polar code of length N, determining, based on one or more criteria, a plurality of locations within the codeword to insert error correction codes generating the error correction codes based on corresponding portions of the information bits, inserting the error correction codes at the determined plurality of locations, and transmitting the codeword. Other aspects, embodiments, and features are also claimed and described.

A computing device includes an interface configured to interface and communicate with a storage network, a memory that stores operational instructions, and a processing module operably coupled to the interface and memory configured to transmit a write request for a first write threshold number of encoded data slices of a set of encoded data slices to a set of storage units associated with a first storage site and transmit a write request for a second write threshold number of encoded data slices to a set of storage units associated with a second storage site. The processing module is configured to receive a read request for a read threshold number of encoded data slices of the set of encoded data slices, determine whether a read threshold number of encoded data slices of the set of encoded data slices is available in the set of storage units associated with the first storage site and when a read threshold number of encoded data slices of the set of encoded data slices is not available in the set of storage units associated with a first storage site, transmit a read request for a read threshold number of encoded data slices to the set of storage units associated with a second storage site.

A storage system includes a first information processor, a second information processor, and a superordinate device. The first information processor includes a first memory device that stores therein the data, a difference generator that generates difference data representing a difference between updating data received from the superordinate device and the data stored in the first memory device before updating, a second memory device stores therein the generated difference data, and a data transmitter that transmits the stored difference data to the second information processor. The second information processor includes a third memory device that stores therein the parity, a data receiver that receives the difference data transmitted from the data transmitter, and a parity difference applier that generates a post-updating parity that is to be written into the third memory device by applying the received difference data to the stored parity before the updating.

Techniques described and suggested herein include systems and methods for optimizing performance characteristics by differentiating data storage device types for data archives stored on data storage systems using redundancy coding techniques. For example, redundancy coded shards, which may include identity shards that contain unencoded original data of archives, may be stored on different types of data storage devices to optimize for various retrieval use cases and implemented environments. Implementing systems may monitor various performance characteristics so as to adaptively account for changes to some or all of the monitored parameters.

The present invention is directed to communication systems and methods. In a specific embodiment, the present invention provides a receiver that includes an error correction module. A syndrome value, calculated based on received signals, may be used to enable the error correction module. The error correction module includes an error generator, a Nyquist error estimator, and a decoder. The decoder uses error estimation generated by the Nyquist error estimator to correct the decoded data. There are other embodiments as well.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits to be transmitted in a current frame; a parity permutator configured to perform parity-permutation by interleaving the parity bits and group-wise interleaving a plurality of bit groups configuring the interleaved parity bits based on a group-wise interleaving pattern including a first pattern and a second pattern; a puncturer configured to puncture some of the parity-permutated parity bits; and an additional parity generator configured to select at least some of the punctured parity bits to generate additional parity bits to be transmitted in a previous frame of the current frame, based on the first pattern and the second pattern, wherein the first pattern determines parity bits to remain after the puncturing and then to be transmitted in the current frame.

A decoder includes one or more Variable-Node Processors (VNPs) that hold respective variables, and logic circuitry. The logic circuitry is configured to decode a code word of an Error Correction Code (ECC), which is representable by a set of check equations, by performing a sequence of iterations such that each iteration involves processing of at least some of the variables, to hold one or more auxiliary equations derived from the check equations, so that a number of the auxiliary equations is smaller than a number of the check equations, to evaluate the auxiliary equations, during the sequence of iterations, using the variables, and, in response to detecting that the variables satisfy the auxiliary equations, to terminate the sequence of iterations and output the variables as the decoded code word.