Save both Raft state and K/V snapshot as a single atomic action, to help avoid them getting out of sync.

attach server i to servers listed in to caller must hold cfg.mu

attach server i to servers listed in to caller must hold cfg.mu

detach server i from the servers listed in from caller must hold cfg.mu

detach server i from the servers listed in from caller must hold cfg.mu

获取持久化的数据

自定义锁

自定义锁

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[].

shard server name for labrpc. i'th server of group gid.

wait for at least n servers to commit. but don't wait forever.

A service wants to switch to snapshot. Only do so if Raft hasn't have more recent info since it communicate the snapshot on applyCh. 其实CondInstallS

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 will have to modif

Maximum log size across all servers

创建一个task

the service says it has created a snapshot that has all info up to and including index. this means the service no longer needs the log through (and in

send an RPC request to the coordinator, wait for the response. usually returns true. returns false if something goes wrong.

check that no server's log is too big.

timeout = 0 means no timeout if this operation times out, then a false positive is possible

caller should hold cfg.mu

caller should hold cfg.mu

Check that ops are committed fast enough, better than 1 per heartbeat interval

the tester calls Kill() when a ShardCtrler instance won't be needed again. you are not required to do anything in Kill(), but it might be convenient

the tester calls Kill() when a KVServer instance won't be needed again. for your convenience, we supply code to set rf.dead (without needing a lock),

the tester calls Kill() when a ShardKV instance won't be needed again. you are not required to do anything in Kill(), but it might be convenient to (

判断是否存在指定config和指定shardId的output shard

shared by Put and Append. you can send an RPC with code like this: ok := ck.servers[i].Call("KVServer.PutAppend", &args, &reply) the types of args

shared by Put and Append. You will have to modify this function.

Shutdown a server by isolating it

Maximum snapshot size across all servers

* 初始化代码 */ servers[] contains the ports of the set of servers that will cooperate via Raft to form the fault-tolerant shardctrler service. me is the

If restart servers, first call ShutdownServer

* 配置调整代码 */ 配置的调整 我们的策略是尽量不改变当前的配置

check that for a specific client all known appends are present in a value, and in order

check that everyone agrees on the term. 检验每一个节点的term是否一致,并返回

Cook up a unique-ish UNIX-domain socket name in /var/tmp, for the coordinator. Can't use the current directory since Athena AFS doesn't support UNIX-d

map任务时获取要输出的文件名

returns "" or error string

判断当前raft的日志记录是否超过发送过来的日志记录

读取快照 两处调用：初始化阶段；收到Snapshot命令，即接收了leader的Snapshot

读取快照 两处调用：初始化阶段；收到Snapshot命令，即接收了leader的Snapshot

重置单个timer

立马发送

扫描任务状态并适当更新

spawn ncli clients and wait until they are all done

调用start向raft请求命令

caller should hold cfg.mu