Distributed paradigms
Distributed paradigms

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Distributed paradigms

2.4 The message passing idea

Figure 1 shows the central idea behind the message passing paradigm. It involves an architecture in which clients and servers communicate using communication lines. In this model, in contrast with the others that are to be presented in this course, the underlying structure of the network is visible via the communication media used to connect servers and clients and devices such as sockets, ports and server sockets which are involved in the transfer of a message from one computer to another.

Figure 1
Figure 1 A message passing architecture

In general message passing is used in applications which satisfy one or more of a number of criteria:

  • Communication needs are very simple.

  • High performance is required; message passing is a much more efficient mechanism than those technologies detailed later in this course. However, you pay for this in terms of programming complexity.

  • Rapid implementation is required, for example an e-commerce application may be required quickly in order to react to a competitor's new website; if there is no time to carry out sophisticated design and you are prepared to countenance the inevitable errors that this brings, then a message passing solution might be chosen.

  • The system uses a technology that no existing protocols will communicate with.

It is worth saying at this point that the message passing architecture detailed here is an abstraction of what really happens, with many communication lines and hardware carrying the messages. Ports, sockets and server sockets are abstractions of some rather nasty low-level entities.

This, then, is an introduction to message passing. An example of this type of development style in action is seen in how to program web servers using HTTP, a protocol which is firmly based on message passing.


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371