leader会为每个follower维护一个nextIndex，表示leader给各个follower发送的下一条log entry在log中的index，初始化为leader的最后一条log entry的下一个位置。leader给follower发送AppendEntriesRPC消息，带着(term_id, (nextIndex-1))， term_id即(nextIndex-1)这个槽位的log entry的term_id，follower接收到AppendEntriesRPC后，会从自己的log中找是不是存在这样的log entry，如果不存在，就给leader回复拒绝消息，然后leader则将nextIndex减1，再重复，知道AppendEntriesRPC消息被接收。 Chen, Y.F., Huang, A.C.: Controller design for a class of underactuated mechanical systems. IET Control Theory Appl. 6(1), 103–110 (2012) Navigate! Sail your raft towards new destinations and overcome their challenges, uncover their story and find new items to help you on your journey! Raft协议的每个副本都会处于三种状态之一：Leader、Follower、Candidate。 Leader：所有请求的处理者，Leader副本接受client的更新请求，本地处理后再同步至多个其他副本；

S5尚未将日志推送到Followers变离线了，进而触发了一次新的选主，而之前离线的S1经过重新上线后被选中变成Leader，此时系统term为4，此时S1会将自己的日志同步到Followers，按照上图就是将日志（2， 2）同步到了S3，而此时由于该日志已经被同步到了多数节点（S1, S2, S3），因此，此时日志（2，2）可以被commit了（即更新到状态机）； a b Heavy Messing (9 June 2018). "First Impressions: Raft - What shall we do with an indie sailor?". AltChar . Retrieved 8 July 2018. a b c d Schulz, Elena (8 April 2018). "Raft - Überleben auf einem Floß: Ozean-Survival-Spiel erscheint im Mai". Gamestar . Retrieved 8 July 2018. Follower将其当前term加一然后转换为Candidate。它首先给自己投票并且给集群中的其他服务器发送 RequestVote RPC （RPC细节参见八、Raft算法总结）。结果有以下三种情况：

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S1又下线了，触发一次选主，而S5有可能被选为新的Leader（这是因为S5可以满足作为主的一切条件：1. term = 5 > 4，2. 最新的日志为（3，2），比大多数节点（如S2/S3/S4的日志都新），然后S5会将自己的日志更新到Followers，于是S2、S3中已经被提交的日志（2，2）被截断了。 Leader在本地生成一个新的log entry，其内容是Cold∪Cnew，代表当前时刻新旧成员配置共存，写入本地日志，同时将该log entry复制至Cold∪Cnew中的所有副本。在此之后新的日志同步需要保证得到Cold和Cnew两个多数派的确认； The player also needs to manage basic needs like hunger and thirst by catching or growing food and purifying water to drink. When growing food, however, the player must protect the food from seagulls. One can do so by killing or driving away the seagull. During the game, the raft may pass by islands that the player can explore to get special items and resources. The player can also dive in coastal regions and collect special items. [12] [3] [8] [9] [10] [11] Synopsis [ edit ] Leader选出后，就开始接收客户端的请求。Leader把请求作为日志条目（Log entries）加入到它的日志中，然后并行的向其他服务器发起 AppendEntries RPC （RPC细节参见八、Raft算法总结）复制日志条目。当这条日志被复制到大多数服务器上，Leader将这条日志应用到它的状态机并向客户端返回执行结果。 Raft日志同步过程 Schulz, Elena (8 April 2018). "Raft - Überleben auf einem Floß: Ozean-Survival-Spiel erscheint im Mai". Gamestar . Retrieved 8 July 2018.

Raft 使用心跳（heartbeat）触发Leader选举。当服务器启动时，初始化为Follower。Leader向所有Followers周期性发送heartbeat。如果Follower在选举超时时间内没有收到Leader的heartbeat，就会等待一段随机的时间后发起一次Leader选举。 Paxos算法详解一文讲述了晦涩难懂的Paxos算法，以可理解性和易于实现为目标的Raft算法极大的帮助了我们的理解，推动了分布式一致性算法的工程应用，本文试图以通俗易懂的语言讲述Raft算法。 一、Raft算法概述 We offer several types of visits to help you become the healthiest version of yourself. We see patients for all types of health problems and conditions. When you schedule an appointment, you’ll be asked about your health concerns or problems you are seeking help with. You’ll then be scheduled for the appropriate visit type. Spong, M.W.: On the robust control of robot manipulators. IEEE Trans. Autom. Control 37(11), 1782–1786 (1992) Huang, A.C., Wu, S.C., Ting, W.F.: A FAT-based adaptive controller for robot manipulators without regressor matrix: theory and experiments. Robotica 24(2), 205–210 (2006)We deliver primary care health services to you and your family with respect, concern, and care. As family medicine providers, our goal is to develop helpful relationships and to ensure your family gets the highest quality treatment to achieve your optimum health and well-being. Meeting your families’ physical and emotional needs through preventative care and comprehensive treatment is our top priority. About This Game By yourself or with friends, your mission is to survive an epic oceanic adventure across Slotine, J.J.E., Li, W.: On the adaptive control of robot manipulators. Int. J. Robot. Res. 6(3), 49–59 (1987)

a b c "What's next for oceanic survival game Raft?". Polygon. 26 June 2018 . Retrieved 8 July 2018.

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consensus）,它是构建具有容错性（fault-tolerant）的分布式系统的基础。 在一个具有一致性的性质的集群里面，同一时刻所有的结点对存储在其中的某个值都有相同的结果，即对其共享的存储保持一致。集群具有自动恢复的性质，当少数结点失效的时候不影响集群的正常工作，当大多数集群中的结点失效的时候，集群则会停止服务（不会返回一个错误的结果）。