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 computer-implemented method may comprise executing, by a first plurality of replicated state machines, a sequence of ordered agreements to make mutations to a data stored in a first data storage of a first type and executing, by a second plurality of replicated state machines, the sequence of ordered agreements to make mutations to the data stored in a second data storage of a second type. First metadata of the mutated data stored in the first data storage may then be received and stored, as may second metadata of the mutated data stored in the second data storage. A comparison of the stored first and second metadata may then be carried out when the data stored in the first data storage that corresponds to the first metadata and the data stored in the second data storage that corresponds to the second metadata have been determined to have settled according to the predetermined one of the sequence of ordered agreements. A selected action may then be carried out depending upon a result of the comparison.

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.

The redundancy control device includes three controllers that output status signals, a majority voting circuit to which a first voltage or a second voltage is supplied as an output signal through an output line of each controller, a switch provided in each output line, a voltage supply unit provided for each output line to supply the second voltage to the output line when the first voltage is lost, a latch circuit provided for each output line to latch the second voltage when the second voltage is supplied thereto and continue to output the second voltage, a comparison circuit provided for each controller to output a comparison signal based on a comparison of the status signals, and a switch control unit provided for each switch to outputs a switch signal to the switch in response to the comparison signal from the comparison circuit.

Systems and techniques are provided for Byzantine agreement in open networks. An indication to change a validation network for an open network from a current validation network to a next validation network may be broadcast. An agreement to change to the validation network to the next validation network may be. An instance of external validity multi-valued Byzantine agreement may be run to determine a continuing sequence number to be used by the next validation network based on the sequence numbers of amendments applied to decentralized database copies stored node computing devices of the open network. The next validation network may be switched to as the validation network for the open network after the continuing sequence number is determined. An amendment validated by the next validation network may be applied to a decentralized database copy. The amendment may include a sequence number that is higher than the continuing sequence number.

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.

In a self-driving autonomous vehicle, a controller architecture includes multiple processors within the same box. Each processor monitors the others and takes appropriate safe action when needed. Some processors may run dormant or low priority redundant functions that become active when another processor is detected to have failed. The processors are independently powered and independently execute redundant algorithms from sensor data processing to actuation commands using different hardware capabilities (GPUs, processing cores, different input signals, etc.). Intentional hardware and software diversity improves fault tolerance. The resulting fault-tolerant/fail-operational system meets ISO26262 ASIL-D specifications based on a single electronic controller unit platform that can be used for self-driving vehicles.

A distributed consensus method for performing data consensus processing in a distributed system that couples one or more client apparatuses and a plurality of server apparatuses via a network, the method including a step in which each server apparatus performs data operation according to a predetermined distributed consensus algorithm, a step in which an auxiliary consensus device, which is an auxiliary device that assists in reaching a consensus in the event of a failure in response to a request from each server apparatus, decides an auxiliary consensus decided value, and a step in which the auxiliary consensus decided value is caused to take precedence over the decided value of the distributed consensus algorithm under conditions under which the auxiliary consensus decided value decided by the auxiliary consensus device and the decided value decided by the distributed consensus algorithm can conflict with each other.

Methods of guaranteed reception and of processing of a digital signal in an avionics system comprise a plurality of computers, each computer comprising processing electronics and a software layer, which, on receipt of an event, carries out the following steps: at a first instant, sending to each of the other computers of a first signal (ACK) of reception of the event; at a second instant termed “TimeOut ACK”, if the electronic computer has not received one of the first signals emanating from one of the other computers, sending of a second failure signal (FAIL) to each of the other computers; at a third instant termed “TimeOut GARANTEED”, if a second failure signal has been received by the computer, absence of taking into account of the event by the computer and if no failure signal has been received by the computer, taking into account of the event by the data processing electronics of the computer.

Described in detail herein is a system for determining the validity of a transaction in a distributed network environment. The system includes a plurality of peer servers. The system broadcast a first transaction to the plurality of peer servers. The system further elects at least one peer leader from the plurality of peer servers. The system further broadcasts a first set of indices associated with a first subset of transactions, received from the plurality of peer servers, to one or more of the plurality of peer servers. The system further executes a first instance of a binary agreement protocol based at least in part on a second subset of indices associated with a second subset of the transactions. The system further outputs a consensus vector comprising one or more of the transactions.