Etcd教程 — 第二章 Etcd集群静态发现_etcd 双节点集群

监听用于和节点之间通信的url，可监听多个，集群内部将通过这些url进行数据交互(如选举，数据同步等)

–initial-advertise-peer-urls
建议用于和节点之间通信的url，节点间将以该值进行通信。

–listen-client-urls
监听的用于和客户端通信的url,同样可以监听多个。

–advertise-client-urls
建议使用的和客户端通信url,该值用于etcd代理或etcd成员与etcd节点通信。

–initial-cluster-token etcd-cluster-1
节点的token值，设置该值后集群将生成唯一id,并为每个节点也生成唯一id,当使用相同配置文件再启动一个集群时，只要该token值不一样，etcd集群就不会相互影响。

–initial-cluster
也就是集群中所有的initial-advertise-peer-urls 的合集

–initial-cluster-state new
新建集群的标志，初始化状态使用 new，建立之后改此值为 existing

#### 2.2.3 执行 goreman启动命令


在 `/root/gore` 下执行：

goreman -f ./Procfile.learner start

`注意`：如果报以下错误，则说明应先安装Etcd然后在使用goreman来配置集群

07:29:58 etcd1 | Starting etcd1 on port 5000
07:29:58 etcd2 | Starting etcd2 on port 5100
07:29:58 etcd3 | Starting etcd3 on port 5200
07:29:58 etcd1 | /bin/sh: etcd: 未找到命令
07:29:58 etcd2 | /bin/sh: etcd: 未找到命令
07:29:58 etcd3 | /bin/sh: etcd: 未找到命令
07:29:58 etcd1 | Terminating etcd1
07:29:58 etcd2 | Terminating etcd2
07:29:58 etcd3 | Terminating etcd3

#### 2.2.4 查看Etcd启动情况


命令：

etcdctl --endpoints=http://localhost:22379 member list

集群内的成员：

8211f1d0f64f3269, started, infra1, http://127.0.0.1:12380, http://127.0.0.1:12379, false
91bc3c398fb3c146, started, infra2, http://127.0.0.1:22380, http://127.0.0.1:22379, false
fd422379fda50e48, started, infra3, http://127.0.0.1:32380, http://127.0.0.1:32379, false

至此，单机上搭建Etcd集群就完成了。


### ※2.3 多机搭建Etcd集群


多机搭建Etcd集群需要注意的是每个机器上的 2379、2380端口要保持开放，否则会搭建失败。


`各主机信息`：  
 ![etcd集群](https://img-blog.csdnimg.cn/7ecd6f882c5d4de0aef1655417c4c5e3.png)


#### 2.3.1 开放端口


开放每台机器上的2379、2380端口的命令：  
 2379：

firewall-cmd --zone=public --add-port=2379/tcp --permanent

2380：

firewall-cmd --zone=public --add-port=2380/tcp --permanent

重启防火墙：

firewall-cmd --reload

查看开放的端口：

firewall-cmd --list-port

关闭firewall：

systemctl stop firewalld.service #停止firewall

systemctl disable firewalld.service #禁止firewall开机启动

#### 2.3.2 下载安装Etcd


这里我们在 `第一章 2.2 Linux安装Etcd` 基础上进行改造从而实现Etcd多机集群，故不再单独在每台机器上下载安装Etcd。


#### 2.3.3 修改配置


1、 在每台机器上 切换至 `/opt/soft/etcd/etcd-download-test/` 目录，将 `etcd` 和 `etcdctl` 这两个二进制文件复制到 `/usr/local/bin` 目录下，这样就可以在系统中直接调用`etcd/etcdctl`这两个程序了。

cp etcd etcdctl /usr/local/bin

2、输入命令etcd，即可启动一个单节点的etcd服务,ctrl+c即可停止服务。这里讲解一下etcd服务启动后控制台显示的各个参数的意义：

{“level”:“info”,“ts”:“2022-06-05T22:46:31.751+0800”,“caller”:“etcdmain/etcd.go:73”,“msg”:“Running: “,“args”:[“etcd”]}
{“level”:“warn”,“ts”:“2022-06-05T22:46:31.751+0800”,“caller”:“etcdmain/etcd.go:105”,“msg”:”‘data-dir’ was empty; using default”,“data-dir”:“default.etcd”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.751+0800”,“caller”:“etcdmain/etcd.go:116”,“msg”:“server has been already initialized”,“data-dir”:“default.etcd”,“dir-type”:“member”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.751+0800”,“caller”:“embed/etcd.go:131”,“msg”:“configuring peer listeners”,“listen-peer-urls”:[“http://localhost:2380”]}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.752+0800”,“caller”:“embed/etcd.go:139”,“msg”:“configuring client listeners”,“listen-client-urls”:[“http://localhost:2379”]}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.752+0800”,“caller”:“embed/etcd.go:308”,“msg”:“starting an etcd server”,“etcd-version”:“3.5.4”,“git-sha”:“08407ff76”,“go-version”:“go1.16.15”,“go-os”:“linux”,“go-arch”:“amd64”,“max-cpu-set”:1,“max-cpu-available”:1,“member-initialized”:true,“name”:“default”,“data-dir”:“default.etcd”,“wal-dir”:“”,“wal-dir-dedicated”:“”,“member-dir”:“default.etcd/member”,“force-new-cluster”:false,“heartbeat-interval”:“100ms”,“election-timeout”:“1s”,“initial-election-tick-advance”:true,“snapshot-count”:100000,“snapshot-catchup-entries”:5000,“initial-advertise-peer-urls”:[“http://localhost:2380”],“listen-peer-urls”:[“http://localhost:2380”],“advertise-client-urls”:[“http://localhost:2379”],“listen-client-urls”:[“http://localhost:2379”],“listen-metrics-urls”:[],“cors”:[“*”],“host-whitelist”:[“*”],“initial-cluster”:“”,“initial-cluster-state”:“new”,“initial-cluster-token”:“”,“quota-size-bytes”:2147483648,“pre-vote”:true,“initial-corrupt-check”:false,“corrupt-check-time-interval”:“0s”,“auto-compaction-mode”:“periodic”,“auto-compaction-retention”:“0s”,“auto-compaction-interval”:“0s”,“discovery-url”:“”,“discovery-proxy”:“”,“downgrade-check-interval”:“5s”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.752+0800”,“caller”:“etcdserver/backend.go:81”,“msg”:“opened backend db”,“path”:“default.etcd/member/snap/db”,“took”:“75.889µs”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.752+0800”,“caller”:“etcdserver/server.go:529”,“msg”:“No snapshot found. Recovering WAL from scratch!”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.753+0800”,“caller”:“etcdserver/raft.go:483”,“msg”:“restarting local member”,“cluster-id”:“cdf818194e3a8c32”,“local-member-id”:“8e9e05c52164694d”,“commit-index”:6}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.753+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d switched to configuration voters=()”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.753+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d became follower at term 3”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.753+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“newRaft 8e9e05c52164694d [peers: [], term: 3, commit: 6, applied: 0, lastindex: 6, lastterm: 3]”}
{“level”:“warn”,“ts”:“2022-06-05T22:46:31.754+0800”,“caller”:“auth/store.go:1220”,“msg”:“simple token is not cryptographically signed”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.754+0800”,“caller”:“mvcc/kvstore.go:415”,“msg”:“kvstore restored”,“current-rev”:1}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.755+0800”,“caller”:“etcdserver/quota.go:94”,“msg”:“enabled backend quota with default value”,“quota-name”:“v3-applier”,“quota-size-bytes”:2147483648,“quota-size”:“2.1 GB”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.755+0800”,“caller”:“etcdserver/server.go:851”,“msg”:“starting etcd server”,“local-member-id”:“8e9e05c52164694d”,“local-server-version”:“3.5.4”,“cluster-version”:“to_be_decided”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.757+0800”,“caller”:“embed/etcd.go:277”,“msg”:“now serving peer/client/metrics”,“local-member-id”:“8e9e05c52164694d”,“initial-advertise-peer-urls”:[“http://localhost:2380”],“listen-peer-urls”:[“http://localhost:2380”],“advertise-client-urls”:[“http://localhost:2379”],“listen-client-urls”:[“http://localhost:2379”],“listen-metrics-urls”:[]}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.757+0800”,“caller”:“etcdserver/server.go:752”,“msg”:“starting initial election tick advance”,“election-ticks”:10}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“caller”:“embed/etcd.go:581”,“msg”:“serving peer traffic”,“address”:“127.0.0.1:2380”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“caller”:“embed/etcd.go:553”,“msg”:“cmux::serve”,“address”:“127.0.0.1:2380”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d switched to configuration voters=(10276657743932975437)”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“caller”:“membership/cluster.go:421”,“msg”:“added member”,“cluster-id”:“cdf818194e3a8c32”,“local-member-id”:“8e9e05c52164694d”,“added-peer-id”:“8e9e05c52164694d”,“added-peer-peer-urls”:[“http://localhost:2380”]}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“caller”:“membership/cluster.go:584”,“msg”:“set initial cluster version”,“cluster-id”:“cdf818194e3a8c32”,“local-member-id”:“8e9e05c52164694d”,“cluster-version”:“3.5”}
{“level”:“info”,“ts”:“2022-06-05T22:46:31.758+0800”,“caller”:“api/capability.go:75”,“msg”:“enabled capabilities for version”,“cluster-version”:“3.5”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.453+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d is starting a new election at term 3”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.453+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d became pre-candidate at term 3”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.454+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d received MsgPreVoteResp from 8e9e05c52164694d at term 3”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.454+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d became candidate at term 4”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.454+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d received MsgVoteResp from 8e9e05c52164694d at term 4”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.454+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“8e9e05c52164694d became leader at term 4”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.454+0800”,“logger”:“raft”,“caller”:“etcdserver/zap_raft.go:77”,“msg”:“raft.node: 8e9e05c52164694d elected leader 8e9e05c52164694d at term 4”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.474+0800”,“caller”:“etcdserver/server.go:2042”,“msg”:“published local member to cluster through raft”,“local-member-id”:“8e9e05c52164694d”,“local-member-attributes”:“{Name:default ClientURLs:[http://localhost:2379]}”,“request-path”:“/0/members/8e9e05c52164694d/attributes”,“cluster-id”:“cdf818194e3a8c32”,“publish-timeout”:“7s”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.475+0800”,“caller”:“embed/serve.go:98”,“msg”:“ready to serve client requests”}
{“level”:“info”,“ts”:“2022-06-05T22:46:33.475+0800”,“caller”:“embed/serve.go:140”,“msg”:“serving client traffic insecurely; this is strongly discouraged!”,“address”:“127.0.0.1:2379”}
{“level”:“info”,“ts”:“2022-0