What happens on renewal fail?

I am going to run sudo certbot --expand -d domain1.com, domain2.com, domain3.com on nginx

But i am wondering what happens if my expand fails? This is a high traffic site so I dont really want to mess with anything.

Also i am using cloudflare as pass through only (its only managing my DNS) and not using encryption on CF.

2 posts were merged into an existing topic: Adding different domains to existing certificate?