Using an example of a remote procedure call, explain how middleware coordinates the interaction of computers in a distributed system.

Question

What will be an ideal response?

Answer 1

In a remote procedure call, an executing component on one computer (A) calls a
procedure or method, which is part of a component that is executing on a different
computer (B). The role of the middleware is to coordinate this interaction. There
are several steps involved in this:
1. The provision of a stub procedure with the same interface as the called
component. Calling this stub procedure initiates a call to the system
middleware.
2. The middleware running on computer A accepts the call and discovers the
location of the called component.
3. It translates the parameters into a standard format and sends these to
computer B along with a request to call the required component.
4. The middleware on computer B converts the parameters into the appropriate
format for the language of the called component and then calls that
component.
5. After execution, the called component returns the result to the middleware
on computer B which then translates this into the middleware standard
format.
6. The result is transmitted to the middleware on computer A, which then
translates that into the appropriate language format and returns it to the
original calling component.