How to

How to configure etcd nodes simultaneously

Note

We assume you have a deeper knowledge of how etcd works. Otherwise, refer to the configuration where you add etcd nodes one by one.

Instead of adding etcd nodes one by one, you can configure and start all nodes in parallel.

1. Create etcd configuration file on every node. You can edit the sample configuration file /etc/etcd/etcd.conf.yaml or create your own one. Replace the node names and IP addresses with the actual names and IP addresses of your nodes:

   node1node2node3

   /etc/etcd/etcd.conf.yaml

   name: 'node1'
   initial-cluster-token: PostgreSQL_HA_Cluster_1
   initial-cluster-state: new
   initial-cluster: node1=http://10.104.0.1:2380,node2=http://10.104.0.2:2380,node3=http://10.104.0.3:2380
   data-dir: /var/lib/etcd
   initial-advertise-peer-urls: http://10.104.0.1:2380 
   listen-peer-urls: http://10.104.0.1:2380
   advertise-client-urls: http://10.104.0.1:2379
   listen-client-urls: http://10.104.0.1:2379
   

   /etc/etcd/etcd.conf.yaml

   name: 'node2'
   initial-cluster-token: PostgreSQL_HA_Cluster_1
   initial-cluster-state: new
   initial-cluster: node1=http://10.104.0.1:2380,node2=http://10.104.0.2:2380,     node3=http://10.104.0.3:2380
   data-dir: /var/lib/etcd
   initial-advertise-peer-urls: http://10.104.0.2:2380 
   listen-peer-urls: http://10.104.0.2:2380
   advertise-client-urls: http://10.104.0.2:2379
   listen-client-urls: http://10.104.0.2:2379
   

   /etc/etcd/etcd.conf.yaml

   name: 'node1'
   initial-cluster-token: PostgreSQL_HA_Cluster_1
   initial-cluster-state: new
   initial-cluster: node1=http://10.104.0.1:2380,node2=http://10.104.0.2:2380,     node3=http://10.104.0.3:2380
   data-dir: /var/lib/etcd
   initial-advertise-peer-urls: http://10.104.0.3:2380 
   listen-peer-urls: http://10.104.0.3:2380
   advertise-client-urls: http://10.104.0.3:2379
   listen-client-urls: http://10.104.0.3:2379
   

2. Enable and start the etcd service on all nodes:

   $ sudo systemctl enable --now etcd
   

   During the node start, etcd searches for other cluster nodes defined in the configuration. If the other nodes are not yet running, the start may fail by a quorum timeout. This is expected behavior. Try starting all nodes again at the same time for the etcd cluster to be created.

3. Check the etcd cluster members. Connect to one of the nodes and run the following command:

   $ sudo etcdctl member list
   

   The output resembles the following:

   2d346bd3ae7f07c4: name=node2 peerURLs=http://10.104.0.2:2380 clientURLs=http://10.104.0.2:2379 isLeader=false
   8bacb519ebdee8db: name=node3 peerURLs=http://10.104.0.3:2380 clientURLs=http://10.104.0.3:2379 isLeader=false
   c5f52ea2ade25e1b: name=node1 peerURLs=http://10.104.0.1:2380 clientURLs=http://10.104.0.1:2379 isLeader=true