Implementations of the present disclosure include setting, by a first consensus node, a timer that runs out before a timeout of a view change; sending, to a second consensus node, a request for one or more consensus messages missing by the first consensus node in response to the timer running out; receiving, from the second consensus node, the one or more consensus messages each digitally signed by a private key of a corresponding consensus node that generates the respective one or more consensus messages; and determining that a block of transactions is valid, if a quantity of commit messages included in the received one or more consensus messages is greater than or equal to 2f+1, where f is a maximum number of faulty nodes that is tolerable by the blockchain based on practical Byzantine fault tolerance.

A consensus building method suitable when f Byzantine failure nodes (f is an integer equal to or larger than 1 and smaller than N/3) are assumed in a network having N nodes (N is an integer equal to or larger than 1) participating in consensus building, comprising the steps of: receiving a first message from other node which communicates that the other node determined a message including data subject to consensus building valid as a proposal, when the number of received first messages reach a predetermined value Q, transmitting a second message to each node which communicates that it is accepting the proposal, and when the number of received first messages do not reach the predetermined value Q, transmitting a third message to each node which communicates that it is dismissing the proposal, when the number of received second messages reach a predetermined value Q, transmitting a fourth message to each note which communicates that it is treating the proposal as agreed in the network, and when the number of received third messages reach a predetermined value Q, transmitting a fifth message for proceeding to a next round (a unit of consensus building process is called “round”.) to each node, wherein the predetermined value Q is an integer equal to or larger than (f+N+1)/2 when a value of f is known, and wherein when the number of received first message reaches a predetermined value Q, a lock is set to limit behaviors thereafter.

A fault tolerant consensus generation and communication system and method is described. Each processing node in the system receives a plurality of measurements from a sensor, calculates a consolidated value for the received plurality of measurements, transmits the consolidated value to other processing nodes, receives consolidated values from the other processing nodes, calculates a consensus value based on the calculated consolidated value and the received one or more consolidated values, transmits the calculated consensus value to the other processing nodes, receives consensus values from the other processing nodes, generates a consensus message based on the calculated consensus value, the received one or more consensus values, and a predefined criterion, and, in a case where the consensus message is not present in a consensus queue, adds the consensus message to the consensus queue.

Example implementations relate to consensus protocols in a stretched network. According to an example, a distributed system includes continuously monitoring network performance and/or network latency among a cluster of a plurality of nodes in a distributed computer system. Leadership priority for each node is set based at least in part on the monitored network performance or network latency. Each node has a vote weight based at least in part on the leadership priority of the node. Each node's vote is biased by the node's vote weight. The node having a number of biased votes higher than a maximum possible number of votes biased by respective vote weights received by any other node in the cluster is selected as a leader node.

A method and system for performing a flexible Byzantine fault tolerant (BFT) protocol. The method includes sending, from a client device, a proposed value to a plurality of replica devices and receiving, from at least one of the plurality of replica devices, a safe vote on the proposed value. The replica device sends the safe vote, based on a first quorum being reached, to the client device and each of the other replica devices of the plurality of replica devices. The method further includes determining that a number of received safe votes for the proposed value meets or exceeds a second quorum threshold, selecting the proposed value based on the determination, and setting a period of time within which to receive additional votes. The method further includes, based on the period of time elapsing without receiving the additional votes, committing the selected value for the single view.

A networked database management system (DBMS) is disclosed. In particular, the disclosed DBMS includes a plurality of nodes, one of which is elected as a designated leader. The designated leader is elected using a consensus algorithm, such as tabulated random votes, RAFT or PAXOS. The designated leader is responsible for managing open coding lines, and determining when to close an open coding line.

A tool for performing remote part reseat actions. Responsive to receiving a request for a scheduled operation, the tool generates an operation table in a push file. Responsive to a determination that there is at least one redundant component for the scheduled operation, the tool identifies the at least one redundant component. The tool determines one or more tolerable errors for the at least one redundant component. The tool appends the at least one redundant component and the one or more tolerable errors to the operation table in the push file. The tool schedules the push file to prescribe one or more recovery operations for the scheduled operation.

A control system for controlling an apparatus or installation, wherein at least one first safety function controls the apparatus or installation, where the control system includes a first safety-oriented control device that is configured to perform the at least one first safety function, where the first safety-oriented control device is also configured as a first safety-oriented control application that is implemented in a cloud, and where the first safety oriented control application and the apparatus or installation are communicatively coupled via a first safety-oriented communication connection.

Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for storing blockchain data. One of the methods includes receiving a plurality of blocks from a blockchain node in the blockchain network; for each of the plurality of blocks: determining a first number of blockchain nodes that store a dataset divided from an error correction coding (ECC) encoded version of the block and a second number of blockchain nodes that store a dataset comprised of redundant bits divided from the ECC encoded version of the block; calculating a priority value of the block based on the first number and the second number; and encoding at least a portion of the plurality of blocks using ECC to generate a plurality of encoded blocks based on the priority value.

Methods, systems, and computer-readable media for a cell-based storage system with failure isolation are disclosed. A first subset of storage nodes is selected from a set of storage nodes of a data store and assigned to a first partition of data. Replicas of the first partition are stored using the first subset. A second subset of storage nodes is selected from the set of storage nodes and assigned to a second partition of data. The second subset is selected based (at least in part) on the membership of the first subset, and the second subset comprises at least one node not present in the first. Replicas of the second partition are stored using the second subset. Access requests associated with the first partition are routed to the first subset of storage nodes. Access requests associated with the second partition are routed to the second subset of storage nodes.