Make fair loss reliable

Question

I'm studying a Distributed System.

I'm following this book "Introduction to Reliable and Secure Distributed Programming" .

In chapter 2, introduce three types of link:

• Fair loss (that I understand is the lighter)
• Stubborn link
• Perfect link.

I saw exercises that ask to make reliable fair loss link during the algorithm creation.

fair loss property say, that according to the book :

Fair-loss: If a correct process p infinitely often sends a message m to a correct process q, then q delivers m an infinite number of times

So assuming that nobody process crash, why this link is so unreliable? Maybe the problem is duplication?

So my real question is:

Can I create, starting from a Fair loss link, a perfect link?

(Obviously I want to change the fair loss, I don't want to replace it with the perfect link, otherwise, the question would be obvious)

Answer 1

You Asked: 'So assuming that nobody process crash, why this link is so unreliable? Maybe the problem is duplication?' Answer: Each link that connects two processes in a computer network (or a distributed system) is a special restricted process. We know that each process can fail; since each link is a kind of process, links can fail as well. Therefore, even every process is correct, the system can be unreliable. Conclusion: If you want to declare that you have a reliable system, you have to indicate that all the processes and links are correct.

You Asked: 'Can I create, starting from a Fair loss link, a perfect link?' Answer: Yes, if you read the book that you mentioned, you can find the answer.