653 results about "Erasure code" patented technology

An efficient method to apply an erasure encoding and decoding scheme across dispersed data stores that receive constant updates. A data store is a persistent memory for storing a data block. Such data stores include, without limitation, a group of disks, a group of disk arrays, or the like. An encoding process applies a sequencing method to assign a sequence number to each data and checksum block as they are modified and updated onto their data stores. The method preferably uses the sequence number to identify data set consistency. The sequencing method allows for self-healing of each individual data store, and it maintains data consistency and correctness within a data block and among a group of data blocks. The inventive technique can be applied on many forms of distributed persistent data stores to provide failure resiliency and to maintain data consistency and correctness.

Latency based selection of fractional-storage servers, including the steps of identifying a first group of fractional-storage servers estimated to have low response latencies in relation to an assembling device. Retrieving, by the assembling device from a second group of fractional-storage servers, enough erasure-coded fragments for reconstructing approximately sequential segments of streaming content. While retrieving the fragments, identifying at least one server from the second group having latency higher than a certain threshold in response to a fragment pull protocol request. And using the fragment pull protocol to replace the identified server with at least one server selected from the first group.

A “PeerStreamer” provides receiver-driven peer-to-peer (P2P) media streaming for loosely coupled P2P networks. Peers in the network perform only simple operations, may cache all or part of the streaming media, do not collaborate with other peers, may be unreliable, and may drop offline or come online during any given streaming session. Clients in the network operate in real-time to coordinate peers, stream media from multiple peers, perform load balancing, handle online/offline states of peers, and perform decoding and rendering the streaming media. In one embodiment, the PeerStreamer uses high rate erasure resilient coding to allow multiple serving peers to hold partial media without conflict, such that clients simply retrieve fixed numbers of erasure coded blocks regardless of where and what specific blocks are retrieved. In another embodiment, the PeerStreamer uses embedded coded media to vary streaming bitrates according to available serving bandwidths and client queue status.

Embodiments provide methodologies for reliably storing data within a storage system using liquid distributed storage control. Such liquid distributed storage control operates to compress repair bandwidth utilized within a storage system for data repair processing to the point of operating in a liquid regime. Liquid distributed storage control logic of embodiments may employ a lazy repair policy, repair bandwidth control, a large erasure code, and/or a repair queue. Embodiments of liquid distributed storage control logic may additionally or alternatively implement a data organization adapted to allow the repair policy to avoid handling large objects, instead streaming data into the storage nodes at a very fine granularity.

The invention discloses a data storage method of a cloud storage system, which comprises the steps of: carrying out coding fragmentation on a file on the basis of a buffer zone erasure code technology to obtain data fragments and check fragments; processing the data fragments and the check fragments to obtain a check identification; storing the check identification in an index server; requesting storage resource information to the index server according to the quantity of the data fragments and the check fragments; sending the data fragments and the check fragments to a plurality of storage nodes according to the storage resource information; judging whether needing to carry out integrity check on the data fragments and the check fragments in the storage nodes; if needing to carry out integrity check on the data fragments and the check fragments in the storage nodes, sending the data integrity check information to the storage nodes, receiving an identification information set returned by the storage nodes, and judging whether data storage errors or data losses exist according to the identification information set, if yes, coding for recovering the data, and sending the recovered data to the corresponding storage nodes.

The invention discloses a node consensus verification method under a league chain network through an asynchronous mode. Each node takes a transaction request from the head of a buffer queue to act as a transaction sequence to be submitted and then encrypts the sequence by using threshold encryption; each node broadcasts the encrypted transaction sequence, ensures the integrity of the transmitted message by using an erasure code and ensures message consistency of different nodes by using a Merkle tree; and all the nodes vote the transaction sequences by using the binary Byzantine consensus agreement to reach a consensus, each node waits for local receiving all the voted transaction sequences and then decrypts the transaction sequences by using threshold decryption so as to finally obtain the decrypted transaction information to act as the transaction request written in blocks within the period. The method is completely decentralized, the system has no timeout mechanism and the broadcast message completely depends on the network bandwidth so that the method has higher network throughput when a large number of nodes exist in the network in comparison with the conventional synchronization Byzantine fault tolerance consensus method.

The invention relates to a block chain account book distributed storage technology based on erasure code, and belongs to the block chain technology field. The technology comprises the following steps:a) the block delay coding strategy allows to delay the coding of a certain number of new blocks to meet the synchronization requirements of other block chain consensus nodes for blocks; B) accordingto the set block coding algorithm, the blocks satisfying the coding condition are cut into k data blocks, each data block having a size of about 1/k of the original block, and further the cut k datablocks are encoded into n (n) k encoded blocks by the erasure coding technology; (c) each block chain node reserves a part of that coding block, and finally the whole block chain network store the coding blocks decentrally; D) when the original block needs to be recovered from the encoded block, the current node collects the remaining encoded block corresponding to the block from the remaining nodes, and then recovers the original block according to the corresponding decoding algorithm. The method reduces the requirement of the block chain for storage resources and improves the utilization rate of storage space.

The recovery of data during programming, such as in the case of a broken word-line, is considered. The arrangement described assumes that k pages may be corrupted when the system finishes programming a block. Then these corrupted pages can be recovered using an erasure code. In order to recover any k pages, the system will compute and temporarily store k parity pages in the controller. These k parity pages may be computed on-the-fly as the data pages are received from the host. Once programming of the block is finished, a post-write read may be done in order to validate that the data is stored reliably. If no problem is detected during EPWR, then the parity pages in the controller may be discarded. In case a problem is detected, and data in up to k pages is corrupt on some bad word-lines, then the missing data is recovered using the k parity pages that are stored in the controller and using the other non-corrupted pages that are read from the block of the memory array and decoded. Once the recovery is complete the block can be reprogrammed and the temporary parity pages in the controller may be discarded upon successfully reprogramming.

A method and apparatus is disclosed herein for low delay access to key-value based storage systems. In one embodiment, the method for putting data into a key-value store comprising dividing the data into K portions, where K is an integer; selecting an erasure coding to apply to the K portions as a function of delay performance of the key-value based storage system including determining a number of parity blocks to generate to satisfy one or both of a delay target of putting the object into the key-value store and a delay target of subsequent read requests based on an offline performance simulation of delay performance when different numbers of parity blocks are used given the delay distributions obtained through measurements for different request types and object sizes; applying the erasure coding to the K portions to create N blocks of data; sending the N write requests to write blocks of data to the storage system, where each block is assigned a unique key in the key-value store.

The invention discloses a user-oriented cloud storage data integrity protection method. The method includes the steps of 1, uploading, wherein a user side segments and numbers a file to generate intra-block redundancy check codes, the hash value of each file block is calculated and saved as a range-based 2-3 tree, the hash values are linked into one value and signed with private keys, and inter-block redundancy check codes are generated and encrypted with stream substitution secret keys; 2, verification, wherein a cloud management node sends a verification request to a corresponding cloud storage server, corresponding original data and algebraic signatures of the inter-block redundancy check codes corresponding to the original data are calculated and returned to the user side for data integrity verification, and the step 3 is executed if data destruction is found; 3, recovery, wherein the user side acquires all the file blocks on corresponding branch trees from a cloud side according to tree information and performs error recovery on the file blocks through erasure codes of the file blocks. According to the method, integrity verification and recovery are performed on the dynamic data stored in the cloud side from the user perspective.

The invention discloses a file processing method, which comprises the following steps of: encoding a file into a plurality of data blocks by utilizing an erasure code algorithm, and storing the plurality of data blocks in at least two storage nodes which at least comprise storage nodes in a distributed file system; wherein one data block is only stored once; and storing the file index of the file,the respective storage address of each data block in the plurality of data blocks and the hash value related to the file in a block chain network. Therefore, the data redundancy is greatly reduced, higher data reliability is obtained with lower data redundancy, and the utilization rate of the storage space is improved. Moreover, the method adopts a mode of combined storage of the block chain network and the out-of-chain distributed storage system, so that the storage pressure of the block chain network is reduced, and the storage capacity is expanded by introducing the distributed file system. The invention further discloses a file processing device, equipment, a medium and a computer program product.

Using a distributed storage to its maximum bandwidth including the following steps: for each group of at least one assembling device, selecting a subgroup of fractional-storage CDN servers according to at least one criterion, whereby a plurality of server subgroups are selected for a plurality of assembling device groups. And retrieving, using a pull protocol, by the assembling devices from the subgroups of servers, erasure-coded fragments associated with multiple segments of contents, until the aggregated bandwidth used for retrieving the fragments approaches the aggregated bandwidth of the servers included in the subgroups, and as long as the aggregated bandwidth used for delivering each segment does not exceed the aggregated bandwidth of the servers storing the fragments generated from the segment.

Improved method of encoding and repairing data for reliable storage and transmission using erasure codes, which is efficient enough for implementation in software as well as hardware. A systematic linear coding matrix over GF(2^q) is used which combines parity for fast correction of single erasures with the capability of correcting k erasures. Finite field operations involving the coding and repair matrices are redefined to consist of bitwise XOR operations on words of arbitrary length. The elements of the matrix are selected to reduce the number of XOR operations needed and buffers are aligned for optimal processor cache efficiency. Decode latency is reduced by pre-calculating repair matrices, storing them in a hashed table and looking them up using a bit mask identifying the erasures to be repaired.

The invention discloses a mixed cloud storage method based on file access frequency. The mixed cloud storage method based on the file access frequency includes the following steps: adopting a multi-copy mode storage strategy for a new file when the new file is uploaded to a file system; adopting an erasure code coding mode storage strategy for the file after the file is completely uploaded to the file system; periodically counting access frequency of each file in the file system, and dividing files into three categories which are respectively high frequency files, medium frequency files and low frequency files; adopting different storage strategies for different types of data and different types of files in the system; and dynamically adjusting the storage strategies of the files according to changes of the access frequency of the files in the system. The mixed cloud storage method based on the file access frequency classifies the files by periodically counting the access frequency of each file in the file system, adopts different storage strategies for different types of files, and adjusts the storage strategies of the files according to the changes of the access frequency of the files, and therefore the whole file system wholly improves system storage resource utilization rate on the premises of guaranteeing data reliability and access speed.

Fast retrieval and progressive retransmission of content, including the steps of obtaining erasure-coded fragments by an assembling server from fractional-storage CDN servers; reconstructing a streaming content file from the obtained fragments; and streaming the reconstructed content or a transcoded version of the content by the assembling server to a client device. Wherein most of the fractional-storage CDN servers are located close to or on the Internet backbone, and streaming the reconstructed content takes at least an order of magnitude longer than obtaining the fragments and reconstructing the content.

A system and method are provided for peer-to-peer distributed file storage in a network of connected clients. The method transmits data file peer-storage information from a first peer node to a network-connected backup manager. The backup manager creates a mapping plan, for mapping data file segments to a peer group, which typically includes a plurality of network-connected peer nodes. The backup manager transmits the mapping plan to the first peer node. The first peer node distributes the data file segments to the peer group in accordance with the mapping plan, for storage in tangible memory media. Typically, the first peer node accepts a data file and encrypts the data file. In one aspect, the backup manager creates a mapping plan for distributing (n+x) erasure-coded segments. After receipt of the mapping plan, the first peer node creates the (n+x) erasure coded file segments in preparation for distribution.

Embodiments provide methodologies for reliably storing data within a storage system using liquid distributed storage control. Such liquid distributed storage control operates to compress repair bandwidth utilized within a storage system for data repair processing to the point of operating in a liquid regime. Liquid distributed storage control logic of embodiments may employ a lazy repair policy, repair bandwidth control, a large erasure code, and/or a repair queue. Embodiments of liquid distributed storage control logic may additionally or alternatively implement a data organization adapted to allow the repair policy to avoid handling large objects, instead streaming data into the storage nodes at a very fine granularity.