--- title: How to Add and Remove Members description: Guide to dealing with membership in etcd cluster weight: 1300 categories: [Task] upstream_link: "https://github.com/etcd-io/website/blob/824597935df6e95992ef61c07e3222f4f796ca6c/content/en/docs/v3.7/tasks/operator/how-to-deal-with-membership.md" aliases: [/etcd/tasks/operator/how-to-deal-with-membership/] --- `member` to add,remove,update membership: ![13_etcdctl_member_2016062301](/docs/etcd/tasks/img/manage-members.gif) ```shell # For each machine TOKEN=my-etcd-token-1 CLUSTER_STATE=new NAME_1=etcd-node-1 NAME_2=etcd-node-2 NAME_3=etcd-node-3 HOST_1=10.240.0.13 HOST_2=10.240.0.14 HOST_3=10.240.0.15 CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380 # For node 1 THIS_NAME=${NAME_1} THIS_IP=${HOST_1} etcd --data-dir=data.etcd --name ${THIS_NAME} \ --initial-advertise-peer-urls http://${THIS_IP}:2380 \ --listen-peer-urls http://${THIS_IP}:2380 \ --advertise-client-urls http://${THIS_IP}:2379 \ --listen-client-urls http://${THIS_IP}:2379 \ --initial-cluster ${CLUSTER} \ --initial-cluster-state ${CLUSTER_STATE} \ --initial-cluster-token ${TOKEN} # For node 2 THIS_NAME=${NAME_2} THIS_IP=${HOST_2} etcd --data-dir=data.etcd --name ${THIS_NAME} \ --initial-advertise-peer-urls http://${THIS_IP}:2380 \ --listen-peer-urls http://${THIS_IP}:2380 \ --advertise-client-urls http://${THIS_IP}:2379 \ --listen-client-urls http://${THIS_IP}:2379 \ --initial-cluster ${CLUSTER} \ --initial-cluster-state ${CLUSTER_STATE} \ --initial-cluster-token ${TOKEN} # For node 3 THIS_NAME=${NAME_3} THIS_IP=${HOST_3} etcd --data-dir=data.etcd --name ${THIS_NAME} \ --initial-advertise-peer-urls http://${THIS_IP}:2380 \ --listen-peer-urls http://${THIS_IP}:2380 \ --advertise-client-urls http://${THIS_IP}:2379 \ --listen-client-urls http://${THIS_IP}:2379 \ --initial-cluster ${CLUSTER} \ --initial-cluster-state ${CLUSTER_STATE} \ --initial-cluster-token ${TOKEN} ``` Then replace a member with `member remove` and `member add` commands: ```shell # get member ID export ETCDCTL_API=3 HOST_1=10.240.0.13 HOST_2=10.240.0.14 HOST_3=10.240.0.15 etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 member list # remove the member MEMBER_ID=278c654c9a6dfd3b etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 \ member remove ${MEMBER_ID} # add a new member (node 4) export ETCDCTL_API=3 NAME_1=etcd-node-1 NAME_2=etcd-node-2 NAME_4=etcd-node-4 HOST_1=10.240.0.13 HOST_2=10.240.0.14 HOST_4=10.240.0.16 # new member etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379 \ member add ${NAME_4} \ --peer-urls=http://${HOST_4}:2380 ``` Next, start the new member with `--initial-cluster-state existing` flag: ```shell # [WARNING] If the new member starts from the same disk space, # make sure to remove the data directory of the old member # # restart with 'existing' flag TOKEN=my-etcd-token-1 CLUSTER_STATE=existing NAME_1=etcd-node-1 NAME_2=etcd-node-2 NAME_4=etcd-node-4 HOST_1=10.240.0.13 HOST_2=10.240.0.14 HOST_4=10.240.0.16 # new member CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_4}=http://${HOST_4}:2380 THIS_NAME=${NAME_4} THIS_IP=${HOST_4} etcd --data-dir=data.etcd --name ${THIS_NAME} \ --initial-advertise-peer-urls http://${THIS_IP}:2380 \ --listen-peer-urls http://${THIS_IP}:2380 \ --advertise-client-urls http://${THIS_IP}:2379 \ --listen-client-urls http://${THIS_IP}:2379 \ --initial-cluster ${CLUSTER} \ --initial-cluster-state ${CLUSTER_STATE} \ --initial-cluster-token ${TOKEN} ```