Patroni

How to Add and Remove Members

Guide to dealing with membership in etcd cluster

member to add,remove,update membership:

13_etcdctl_member_2016062301

# 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:

# 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:

# [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}

Last modified October 25, 2021: adding weights to tutorials section. Setting weight for the Tutorials page to be just below old Demos page. Setting weight in individual pages to match order in old Demos page. (#530) (f54f357)