etcd dynamic discovery should join the cluster first or start process first?

[lengbingbin]

etcd dynamic discovery should join the cluster first or start process first?Why?

when etcd got an error and broken down, should I use "member add" to add member to the cluster and start process or start process first? Why? I have try two ways and get success all,but many answers told me should add member to the cluster and I do not why.

Thank you for answering