ยป Consul Enterprise Automated Upgrades
Consul Enterprise supports an upgrade pattern that allows operators to deploy a complete cluster of new servers and then just wait for the upgrade to complete. As the new servers join the cluster, server introduction logic checks the version of each Consul server. If the version is higher than the version on the current set of voters, it will avoid promoting the new servers to voters until the number of new servers matches the number of existing servers at the previous version. Once the numbers match, Autopilot will begin to promote new servers and demote old ones.