What's the difference between Downtime and Maintenance mode?

[leiless]

Hi, @shlomi-noach.

$ orchestrator-client -c help | grep maintenance -C2
    begin-downtime                           Mark an instance as downtimed
    end-downtime                             Indicate an instance is no longer downtimed
    begin-maintenance                        Request a maintenance lock on an instance
    end-maintenance                          Remove maintenance lock from an instance

As from the documentation, the difference between downtime and maintenance mode is unclear.

Also, how do those two modes affect graceful/automatic failover?

SEE ALSO: https://github.com/openark/orchestrator/issues/1244

[leiless]

As I tested, why I can promote a downtimed instance from replica into master in web UI by graceful-master-takeover?