Remote Procedure Calls
Paul Krzyzanowski · 2002
OCKETS are a fundamental part of client-server networking. They provide a relatively easy mechanism for a program to establish a connection to another program, either on a remote or local machine and send messages back and forth (we can even use read and write system calls). This interface, however, forces us to design our distributed applications using a read/write (input/output) interface which is not how we generally design non-distributed applications. In designing centralized applications, the procedure call is usually the standard interface model. If we want to make distributed computing look like centralized computing, input-output-based communications is not the way to accomplish this. In 1984, Birrell and Nelson devised a mechanism to allow programs to call procedures on other machines. A process on machine A can call a procedure on machine B. The process on A is suspended and execution continues on B. When B returns, the return value is passed to A and A continues execution. This mechanism is called the Remote Procedure Call (RPC). To the programmer, the goal is that it should appear as if a normal procedure call is taking place. Obviously, a remote procedure call is different from a local one in the underlying implementation.