I have 3 sentinels monitoring a master slave setup with a quorum of 2, I would like to increase this to 5 sentinels and a quorum of 3. However when I run SENTINEL SET master quorum 3 the change is not propagated to the other 2 sentinels. Is this correct, if a fail over does happen is the value of the last change taken?
This is intended behavior. All master level commands must be sent to each sentinel individually, it does not propagate commands to other sentinels. Send the command to each of your five sentinels and you will get the effect you are after.