P2P or Distributed System implementation

Question

Hi,

I have the work of implementing a distributed system of nodes (like p2p nodes) each of these nodes (lets say A,B,C and D) perform certain functions and need to interact with each other for various operations such as synchronize operations and other things like 15 A nodes interact with a group of 5 B nodes to get into the least loaded node's queue and get a token number and thereafter wait for C to redirect them to a free node D and so on.

I am a bit lost as to how should i go about the design:

1. The protocol that i have thought of is to encapsulate a struct of the type of operation and other things to be sent. Also, this is done using an acknowledgment scheme so i can be sure the other side got the message.
2. How do i go about the distributed mutual exclusion aspect as I do not have a central server. I am guessing each node replicates the data, but this sounds a bit too expensive(not to mention stupid).
3. What is the basic design methodology followed while implementing p2p systems, ie how do i implement the program such that it is blocked on a receive but also can send further updates et al and at the same time get information from others about the 'state' of the whole system.

Also, what are the other issues that I may need to look at/face. I also would appreciate if you could point me towards some good online resources on implementing p2p and distributed systems.

Thanks!!

Answer 1

It would probably be a good idea to do some research on consistent hashing schemes. A nice starting point:

• http://www.lexemetech.com/2007/11/consistent-hashing.html

I'm sure if you do some basic googling on "design peer to peer" type stuff you'll find lots of things to read. You might also look at some design docs for popular peer to peer apps like Gnutella, BitTorrent, etc.