Change

If we were to talk about old messaging system where there exist post-office, postman & mailbox. each component had its own functionality that we looked for when trying to visualize how those component where to interact in a computerized version. Simple scenario: Mail is added in mail box Postman arrive pick mails from his area mailboxes and take them to the post-office. Post-office organize mails by areas. Postman takes mails related to his area "distribute it in mailboxes". A person can go to post-office and  pick his own mail "in case of failure or wishes for early delivery". Mapping in a computerized version: Scenario: Observer design pattern which can use push or pull scenario, to inform those whom are registered for an event about its occurrence. Component: Post-Office = Message-Broker Post-Office-Box = Message-Storage-Validity Mailbox = Topic/Queue Postman !!! where's the postman ? Apache kafka act as a message broker which d