Message-Passing Systems
Program is based on typically coarse-grain tasks
Separate address space and a processor number for each task
Data shared by explicit messages
- Point-to-point and collective communications patterns
Examples: MPI, PVM, Occam for parallel computing
Universal model for distributed computing to link naturally decomposed parts e.g. HTTP, RMI, IIOP etc. are all message passing
- distributed object technology (COM, CORBA) built on functionally concurrent objects sending and receiving messages
Advantages:
- Close to hardware ALWAYS
- Can be close to problem as in distributed objects or functional parallelism
Disadvantages:
- Many low-level details when NOT close to problem.