What is meant by state machine replication?
In computer science, state machine replication (SMR) or state machine approach is a general method for implementing a fault-tolerant service by replicating servers and coordinating client interactions with server replicas.
What is a state machine distributed systems?
The state machine approach is a general method for achieving fault tolerance and implementing decentralized control in distributed systems. This paper reviews the approach and identifies abstractions needed for coordinating ensembles of state machines.
What are the basic 2 requirements needed to create replicas in state machine replication PBFT?
PBFT is often considered to be the first practical algorithm in the area [3]. Although its performance seems adequate for many applications, its costs are considerable, requiring at least 4 replicas (n = 3f +1 with f = 1) and 5 communication steps in normal operation (worse in case there are faults).
What is state machine replication in Blockchain?
The state machine approach is a general method for implementing a fault-tolerant distributed system by replicating services and coordinating client interactions across service replicas. A replicated state machine is deterministic in that it consists of a set of state variables that encode its state and transactions.
Where is raft consensus used?
A consensus algorithm is used to agree on the commands in the servers’ logs. The consensus algorithm must ensure that if any state machine applies set x to 3 as the nth command, no other state machine will ever apply a different nth command.
What is finite state machine in distributed system?
One of the simplest and best-understood models of computation is the Finite State Machine (FSM). An FSM has fixed range of states it can be in, and is always in one of these states. When an input arrives, this triggers a transition in the FSM from its current state to the next state.
What is paxos?
Paxos is a family of protocols for solving consensus in a network of unreliable or fallible processors. Consensus is the process of agreeing on one result among a group of participants. This problem becomes difficult when the participants or their communications may experience failures.
What is practical Byzantine fault tolerance?
Practical Byzantine Fault Tolerance is a consensus algorithm introduced in the late 90s by Barbara Liskov and Miguel Castro. pBFT was designed to work efficiently in asynchronous(no upper bound on when the response to the request will be received) systems. It is optimized for low overhead time.
What are the two types of state machines?
Finite-state machines are of two types—deterministic finite-state machines and non-deterministic finite-state machines. A deterministic finite-state machine can be constructed equivalent to any non-deterministic one.
What is virtual machine replication?
Utilize a “seed copy” of virtual machine data for the initial synchronization to reduce the amount of time required to create the initial copy
What is storage replication service?
Editing and deleting records in a replicated database. When you edit or delete a record,you affect the data in use at other sites.
What is a replication site?
Site replication is a feature that allows you to create replicated sites for your affiliates. In post affiliate pro, a special type of banner is replicated, and you can create an unlimited number of similar.
What is resource replication?
Resource replication is defined as the creation of multiple instances of the same IT resource, and is typically performed when an IT resource’s availability and performance need to be enhanced. Virtualization technology is used to implement the resource replication mechanism to replicate cloud-based IT resources (Figure 1).