CareerCup

As far as i understood the question here is what i think the answer would be:
Since the users have access to the five servers and not the integration server,the user can send a password change request to any of these five servers.The idea is to not change the password in the server that the request comes in instead the request is forwarded to the integration server that will handle the request and send a notification to all the five servers to change the password.There should be some kind of a response mechanism in these five servers acknowledging the change of password with the integration server otherwise the integration server should send the request again.

Hope this helps!

I think, this is possible using Observer Design Pattern Please see Link at name section
See the real word example (this demo Stock Problem ) However In this problem
Subject will be Users {}
Concrete Subject Each User : Users {}
Observer IServer {}
Concrete Server : IServer {}