ClassicGuard

ClassicGuard is the first implementation of relative debugger. It has been implemented in most Unix machines, and is command line driven. It has a client server architecture, and uses GDB as the portable debug server implementation.

ClassicGuard uses a client/server model in order to ensure that the processes being debugged can be distributed onto multiple platforms and can be controlled independently. In this architecture, each of the debug servers is responsible for managing a single process that is being debugged. The following picture shows the architecture of ClassicGuard

The above diagram shows a scenario where the user is debugging a serial process S1 on host A and a parallel program compromising two processes P1 and P2 on hosts A and B respectively. The client/server architecture places no distinction on the host running the debugger client, so in this case it is located on a third machine, host C.

Both the client and server that make up the debugger are designed to be as modular as possible. To achieve this, a three-layer model has been adopted for both the client and the server. The following diagram shows the components that make up the debugger