Thanks to propose your help !

What I find vague in "ZooKeeper and consensus" is the answer to "Why does this proposal work compared to the original one?":

>> Because each of the workers has “proposed” a single value

Does the processes read or propose the value ?

>> and no changes to those values are supposed to occur.

Not suppose to ? How do you ensure that ?

>> Over time, as the configurator changes the value,

>> they can agree on the different values by running independent instances

>> of this simple agreement recipe.

Sorry, but I fail to see what recipe you speak about.