Zero-downtime upgrade for HashiCorp Nomad server or client

Question

What is the recommended methodology to upgrade a HashiCorp Nomad server or client on CentOS Linux 7.5 without downtime?

I'm trying to migrate from v0.10.4 to the just-released v0.11.

Is there a way to perform a lazy-upgrade that will defer/wait for existing tasks to end before swapping binaries to ensure zero downtime?

Answer 1

The official Nomad upgrade guide covers everything you need.

Basically the process consists of the following steps

• Replace an old Nomad binary with a new one
• Restart Nomad process

I've just tested it on one of my staging servers and it worked like a charm. Docker containers have not been restarted during the Nomad update process.