Which part of Appian architecture relays messages between different components?

In Appian architecture, the component responsible for relaying messages between different parts of the system is the Internal Messaging Service. This service facilitates communication and coordination between various components of the Appian platform, ensuring that data and notifications are passed reliably across different systems and applications.

The Internal Messaging Service plays a crucial role in maintaining the flow of information, especially in scenarios where components need to respond to events occurring within the application or where asynchronous processing is required. By utilizing this service, Appian allows for a more decoupled architecture, where components can interact without needing to be directly linked, enhancing scalability and maintainability.

While other components, such as the Data Server and Application Server, play vital roles in storing and retrieving data or handling application logic, they do not specifically focus on the communication aspects that the Internal Messaging Service provides. The Process Modeler is primarily a tool used for designing process flows rather than managing inter-component messaging. Thus, the Internal Messaging Service is essential for enabling seamless interaction within the Appian ecosystem.