Architecture of the Message Info Service 
Communication within the Java cluster is administered by the Cluster Manager. If a server process wants to send a message or data, this is arranged by the Cluster Manager, which connects to the Message Server.
The Message Server is managed by the Message Info Service.
The figure below
shows the relationships between the components Cluster Manager, Message
Server, and Message Info Service.
Message Server and Message Service are used synonymously here. The correct expression would be that the Message Server is a process or program that provides the Message Service.
For information
about the architecture of the SAP Web AS for Java, see the 
Architecture
Manual.
See also: