Update expiring Mongo cluster SSL certificate I have a multi-node mongo cluster using SSL requireSSL and the certificates are going to expire. Is there a zero-downtime method to update the certs? I know the easiest way would be to stop all nodes, swap out the certs, and restart mongo. Same for all clients. I have not found a way to execute it without a service interruption.
If you CA don't change, just cert expiration time, you should not have any problems to change cert one node at the time (rolling upgrade).

But...
Basically following this procedure, so you "downgrade" you nodes ssl level allowSSL and doing change of certificate one node at time. After that you can bring ssl level back to requireSSL after everybody have new certs.