Please enable JavaScript.

Coggle requires JavaScript to display documents.

Session 3 - Event Driven (Advantages/Disadvantages (Great autonomy of the…

- - - - Contains all the event channels
      - It is a central component
      - Event channels can be message queues, message topics or a combination
    - - Responsible for processing an event
      - Publishes a new event that indicates what action it performed.
      - The events published are picked by other event processors (or not)
  - - - Hard to handle errors since there is no component that centralizes them.
    - - If there is something that needs to happen when a process is done, we need to wait until the end.
      - There can be another processor that just waits for all the rest of the events to be processed.
    - - It is very simple to add a new event processor.
- - - - This is used to transport the initial (external) events to the mediator
    - - Receives the event and orchestrates the event by sending additional asynchronous events to event channels
    - - Listen to event channels
      - Receive events from the mediator
      - Has the business logic that needs to be executed
  - - - It is easy to handle errors ??
    - - It is easy, cause we know when the changes are done
      - The mediator gives the impression of a transactional environment
    - - Hard to implement
      - When we need to add a new process, we have to change the entire mediator
      - There will be a team responsible with the mediator, which can become a bottleneck.
- - - - It is a DTO.
      - Contains all the data needed by the business logic components to execute
      - Anemic models, only contain data.
      - Change the state of an object (entity), also known as modifiers or mutators.
    - - Gets the data from the database.
      - It should provide the data as quick as possible
      - Only return the state of an entity, without changing it's state.
    - - It is responsible to execute a command or to pass it to the responsible domain object.
      - Can Take care of additional operations: authorization, logging, reporting.
      - It handles the results and errors.
  - - - If there is no other update to the data, eventually all accesses will return the last updated value
      - It's a type of weak consistency: the system does not guarantee that subsequent accesses will return the updated value
      - More about here