环境：tidb4.0、centos7
1、查看集群节点信息
tiup cluster display tidb
2、剔除节点
tiup cluster scale-in tidb --node 172.21.210.39:20160
其中 --node 参数为需要下线节点的 ID。
预期输出 Scaled cluster <cluster-name> in successfully 信息，表示缩容操作成功。
[root@host-172-21-210-32 ~]# tiup cluster scale-in tidb --node 172.21.210.39:20160
Starting component `cluster`: scale-in tidb --node 172.21.210.39:20160
This operation will delete the 172.21.210.39:20160 nodes in `tidb` and all their data.
Do you want to continue? [y/N]: y
Scale-in nodes...
+ [ Serial ] - SSHKeySet: privateKey=/root/.tiup/storage/cluster/clusters/tidb/ssh/id_rsa, publicKey=/root/.tiup/storage/cluster/clusters/tidb/ssh/id_rsa.pub
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.39
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.32
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.34
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.32
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.38
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.33
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.32
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.26
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.32
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.35
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.36
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.34
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.33
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.32
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.37
+ [Parallel] - UserSSH: user=tidb, host=172.21.210.27
+ [ Serial ] - ClusterOperate: operation=ScaleInOperation, options={Roles:[] Nodes:[172.21.210.39:20160] Force:false SSHTimeout:5 OptTimeout:120 APITimeout:300 IgnoreConfigCheck:false RetainDataRoles:[] RetainDataNodes:[]}
Delete store 14299 172.21.210.39:20160 from the cluster success
The component `tikv` will be destroyed when display cluster info when it become tombstone, maybe exists in several minutes or hours
+ [ Serial ] - UpdateMeta: cluster=tidb, deleted=`''`
+ [ Serial ] - UpdateTopology: cluster=tidb
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.38, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.32, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/grafana-3000.service, deploy_dir=/data1/tidb-deploy/grafana-3000, data_dir=[], log_dir=/data1/tidb-deploy/grafana-3000/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.35, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.33, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/pd-2379.service, deploy_dir=/data1/tidb-deploy/pd-2379, data_dir=[/data1/tidb-data/pd-2379], log_dir=/data1/tidb-deploy/pd-2379/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.27, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.26, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.33, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tidb-4000.service, deploy_dir=/data1/tidb-deploy/tidb-4000, data_dir=[], log_dir=/data1/tidb-deploy/tidb-4000/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.32, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/pd-2379.service, deploy_dir=/data1/tidb-deploy/pd-2379, data_dir=[/data1/tidb-data/pd-2379], log_dir=/data1/tidb-deploy/pd-2379/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.32, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/prometheus-9090.service, deploy_dir=/data1/tidb-deploy/prometheus-9090, data_dir=[/data1/tidb-data/prometheus-9090], log_dir=/data1/tidb-deploy/prometheus-9090/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.32, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tidb-4000.service, deploy_dir=/data1/tidb-deploy/tidb-4000, data_dir=[], log_dir=/data1/tidb-deploy/tidb-4000/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.37, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.36, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.34, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tidb-4000.service, deploy_dir=/data1/tidb-deploy/tidb-4000, data_dir=[], log_dir=/data1/tidb-deploy/tidb-4000/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.34, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/tikv-20160.service, deploy_dir=/data1/tidb-deploy/tikv-20160, data_dir=[/data1/tidb-data/tikv-20160], log_dir=/data1/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
+ [ Serial ] - InitConfig: cluster=tidb, user=tidb, host=172.21.210.32, path=/root/.tiup/storage/cluster/clusters/tidb/config-cache/alertmanager-9093.service, deploy_dir=/data1/tidb-deploy/alertmanager-9093, data_dir=[/data1/tidb-data/alertmanager-9093], log_dir=/data1/tidb-deploy/alertmanager-9093/log, cache_dir=/root/.tiup/storage/cluster/clusters/tidb/config-cache
Scaled cluster `tidb` in successfully