如一个命令是读v,还有一个是更新v。 但这种话不论是仅仅有一个server的系统还是replication系统,都不能并行运行,仅仅能依照total order来依次处理命令。所以假设命令间是dependent的,replication仅仅能採取串行运行。 这样越说越不正确劲了,这种话replication系统要解决什么问题呢?是让independent的命令并行运行,还是让dep...
State machine replication(SMR)复制状态机用于分布式系统的容错处理,通过增加数据副本的数量提高系统的可靠性和可用性。复制状态机由一系列的进程组成,进程包括无限多个客户端进程C = {c1,c2,...}和有限个服务器进程S = {s1,...,sn}。任何时候,服务器进程的处于以下故障或者正常的状态,即系统不存在拜占庭故障。
State Machine Replication是一项很有效的fault tolerance技术。在这个模型中,程序(比如一个apache server)被视为deterministic state machine,意思就是给程序一定顺序的input requests,程序执行后就会到达一定的状态(准确的说是数据结果),而replication就是在多个nodes中保持相同的state。当然这要求我们的SMR模型可以容忍来自n...
A state machine replication system is a client-sever system ensuring that each state machine replica executes the same sequence of client requests, even if these requests are submitted concurrently by clients and received in different orders by the replicas. Replicas agree on the execution order of ...
1、Scalable State-Machine Replication http://www.inf.usi.ch/faculty/pedone/Paper/2014/2014DSNa.pdf 例如,在一个kv数据库中,按照k将对象分为不同的分组p1,p2,p3...pi。保证每一个对象被至少分配至一个分组p。每个每组p使用服务器组s进行备份。为了执行一个请求C,客户端将C发送至全部访问的对象的所有...
1 Replicated State Machine 在raft协议中,每一个server中都有一个Replicated State Machine,只要每个server接收到的输入命令是相同的,那么Replicated State Machine最后的结果就是相同的,也就达到了最终的共识性。那么我们可以考虑下,如果不使用Replicated State Machine,还有其他的方式吗。其实一共两种方式的复制方式: ...
With active replication,also known as state machine replication, each replica implements a deterministic state machine. All replicas process the same operations in the same order. With passive replication,also known as primary backup, a primary replica runs a deterministic state machine, while backups...
This report presents LibraBFT, a robust and efficient state machine replication system designed for the Libra Blockchain. LibraBFT is based on HotStuff, a recent protocol that leverages several decades of scientific advances in Byzantine fault tolerance (BFT) and achieves the strong scalability and ...
State machine replication (SMR) is the problem of distributing the operation of a state machine across a set of replicas or servers so that the operation of the machine is resilient to failure of some the servers. A server is considered faulty if its behavior is no longer consistent with its...
State-machine replication: active replicationYears and Authors of Summarized Original Work 1978; Lamport Problem Definition This entry covers several problems, related with each other. The first problem is concerned with maintaining the causal relationship between events in adistributed system. The ...