ETCD集羣安裝，常用命令，Go使用分佈式鎖案例

在不同的機器啓動一個cluster

TOKEN=token-01

CLUSTER_STATE=new

NAME_1=machine-1

NAME_2=machine-2

NAME_3=machine-3

HOST_1=10.240.0.17

HOST_2=10.240.0.18

HOST_3=10.240.0.19

CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380

THIS_NAME=${NAME_$1}

THIS_IP=${HOST_$1}

etcd--data-dir=data.etcd --name ${THIS_NAME} \

         --initial-advertise-peer-urlshttp://${THIS_IP}:2380 --listen-peer-urls http://${THIS_IP}:2380 \

         --advertise-client-urlshttp://${THIS_IP}:2379 --listen-client-urls http://${THIS_IP}:2379 \

         --initial-cluster ${CLUSTER} \

         --initial-cluster-state${CLUSTER_STATE} --initial-cluster-token ${TOKEN}

在三臺機器的腳本如下圖所示

在本地機器啓動一個cluster

First install goreman,which manages Procfile-based applications.

Our Procfile script will set up a localexample cluster. Start it with:

goreman start

This will bringup 3 etcd members infra1, infra2 and infra3 andetcd grpc-proxy, which runs locally and composes a cluster.

Every cluster member and proxy accepts key value readsand key value writes.

ETCDCTL_API=3

CMDS

$ etcdctl --endpointshttp://10.16.85.110:2379 put /message hello

$ etcdctl --endpointshttp://10.16.85.110:2379 get /message

$ etcdctl --endpointshttp://10.16.85.110:2379 rm /message

$ curl http://10.16.85.110:2379/v2/keys/message

$ curl http://10.16.85.110:2379/v2/keys

$ curl -X DELETE http://10.16.85.110:2379/v2/keys/message

$ etcdctl --endpointshttp://10.16.85.110:2379 mkdir /foo-service

$ etcdctl --endpointshttp://10.16.85.110:2379 put /foo-service/container1 localhost:1111

$ etcdctl --endpointshttp://10.16.85.110:2379 get /foo-service/container1

$ etcdctl --endpoints http://10.16.85.110:2379ls /foo-service

$ curl http://10.16.85.110:2379/v2/keys/foo-service/

$ etcdctl --endpointshttp://10.16.85.110:2379 watch --recursive --forever /foo-service

$ etcd]$ etcdctl --endpointshttp://10.16.85.110:2379 exec-watch --recursive /foo-service -- sh -c 'echo" \"$ETCD_WATCH_KEY\" key was updated to\"$ETCD_WATCH_VALUE\" value by \"$ETCD_WATCH_ACTION\"action    "'

$ etcdctl --endpointshttp://10.16.85.110:2379 put /message "hi"

$ etcdctl --endpointshttp://10.16.85.110:2379 put /message "hello" --swap-with-value"hi"

 

$ etcdctl --endpointshttp://10.16.85.110:2379 put /foo-ttl "expired soon" --ttl 10

$ etcdctl --endpoints=$ENDPOINTS leasegrant 300

$ etcdctl --endpoints=$ENDPOINTS put samplevalue --lease=2be7547fbc6a5afa

$ etcdctl --endpoints=$ENDPOINTS lockmutex1

$ etcdctl --endpoints=$ENDPOINTS elect onep1

$ etcdctl --write-out=table--endpoints=$ENDPOINTS endpoint status

 

$ etcdctl --endpoints=$ENDPOINTS snapshotsave my.db

$ etcdctl --write-out=table--endpoints=$ENDPOINTS snapshot status my.db

 AUTH

export ETCDCTL_API=3
ENDPOINTS=localhost:2379

etcdctl --endpoints=${ENDPOINTS} role add root

etcdctl --endpoints=${ENDPOINTS} role grant-permission root readwritefoo

etcdctl --endpoints=${ENDPOINTS} role get root

etcdctl --endpoints=${ENDPOINTS} user add root
etcdctl --endpoints=${ENDPOINTS} user grant-role root root
etcdctl --endpoints=${ENDPOINTS} user get root
etcdctl --endpoints=${ENDPOINTS} auth enable
# now all client requests go through auth
etcdctl --endpoints=${ENDPOINTS} --user=root:123 put foo bar
etcdctl --endpoints=${ENDPOINTS} get foo
etcdctl --endpoints=${ENDPOINTS} --user=root:123 get foo
etcdctl --endpoints=${ENDPOINTS} --user=root:123 get foo1

Heartbeat Interval : 100ms

Election Timeout : 1000ms (如果slave持續1000ms內沒有收到master的心跳，則自薦爲master)

Election Timeout應該爲不低於Heartbeat Interval的十倍。

 

# Command line arguments:

$ etcd --heartbeat-interval=100--election-timeout=500

 

# Environment variables:

$ ETCD_HEARTBEAT_INTERVAL=100ETCD_ELECTION_TIMEOUT=500 etcd

 

$ sudo ionice -c2 -n0 -p `pgrepetcd` //增加IO磁盤的優先級

 

GO使用ETCD分佈式鎖

endpoints := strings.Split(config.Conf.EtcdClusterNodes, ",")
	if endpoints != nil && len(endpoints) != 0{ //如果採用分佈式鎖
		cli, err := clientv3.New(clientv3.Config{Endpoints: endpoints})
		if err != nil {
			lib.Log.Panicf("ETCD NewEtcd cli failed , error is %v " , err)
		}
		defer cli.Close()
		s, err := concurrency.NewSession(cli)
		if err != nil {
			lib.Log.Panicf("ETCD NewSession failed , error is %v " , err)
		}
		defer s.Close()
		m := concurrency.NewMutex(s, "/my-lock-mbcp-bc-als/")
		if err := m.Lock(context.TODO()); err != nil {
			lib.Log.Panicf("ETCD NewMutex failed , error is %v " , err)
		}
		defer m.Unlock(context.TODO())
		//誰先搶到這個分佈式鎖誰就可以得到執行機會，搶不到則阻塞在這裏
	}