do a complete agreement. it might choose the wrong leader initially, and have to re-submit after giving up. entirely gives up after about 10 seconds.

tell the shardctrler that a group is joining.

attach server i to the net.

detach server i from the net.

enable/disable a ClientEnd.

check that one of the connected servers thinks it is the leader, and that no other connected server thinks otherwise. try a few times in case re-ele

send an RPC, wait for the reply. the return value indicates success; false means that no reply was received from the server. 请求使用的是每个客户端的chan，req会创建一个

tell the shardctrler that a group is leaving.

the service using Raft (e.g. a k/v server) wants to start agreement on the next command to be appended to Raft's log. if this server isn't the leader

connect a ClientEnd to a server. a ClientEnd can only be connected once in its lifetime.

debug下打印日志

create a client end-point. start the thread that listens and delivers.

start a Test. print the Test message. e.g. cfg.begin("Test (2B): RPC counts aren't too high")

debug下打印日志

debug下打印日志

end a Test -- the fact that we got here means there was no failure. print the Passed message, and some performance numbers.

Basic test is as follows: one or more clients submitting Append/Get operations to set of servers for some period of time. After the period is over, t

start or re-start a Raft. if one already exists, "kill" it first. allocate new outgoing port file names, and a new state persister, to isolate previo

* 通用函数 */ 自定义锁

debug下打印日志

return currentTerm and whether this server believes it is the leader.

返回当前状态机的最后一条日志的任期和索引 索引是一直会增大的，但是我们的日志队列却不可能无限增大，在队列中下标0存储快照

Create a clerk with clerk specific server names. Give it connections to all of the servers, but for now enable only connections to servers in to[].

import "time"

save Raft's persistent state to stable storage, where it can later be retrieved after a crash and restart. see paper's Figure 2 for a description of

start i'th server in gi'th group

start a Test. print the Test message. e.g. cfg.begin("Test (2B): RPC counts aren't too high")

end a Test -- the fact that we got here means there was no failure. print the Passed message, and some performance numbers.

how many servers think a log entry is committed?

rpc请求：报告任务状态

Shutdown i'th server of gi'th group, by isolating it

If restart servers, first call ShutdownServer

shut down a Raft server but save its persistent state.

获取当前存储位置的索引

which shard is a key in? please use this function, and please do not change it.

main/mrcoordinator.go calls Done() periodically to find out if the entire job has finished. 如果工作全部完成，返回true

get/put/putappend that keep counts

the tester doesn't halt goroutines created by Raft after each test, but it does call the Kill() method. your code can use killed() to check whether K

controler server name for labrpc.

用于生成一个随机数，可以生成clientId和commandId

Sets up 2 partitions with connectivity between servers in each partition.

保存快照

debug下打印日志

fetch the current value for a key. returns "" if the key does not exist. keeps trying forever in the face of all other errors. you can send an RPC w

the service or tester wants to create a Raft server. the ports of all the Raft servers (including this one) are in peers[]. this server's port is pee