[Gzz-commits] gzz/Documentation/misc/hemppah-progradu researc...

[Hermanni Hyytiälä]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Hermanni Hyytiälä <address@hidden>      03/01/17 09:09:27

Modified files:
        Documentation/misc/hemppah-progradu: research_problems 

Log message:
        Started formal models

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/misc/hemppah-progradu/research_problems.diff?tr1=1.18&tr2=1.19&r1=text&r2=text

Patches:
Index: gzz/Documentation/misc/hemppah-progradu/research_problems
diff -u gzz/Documentation/misc/hemppah-progradu/research_problems:1.18 
gzz/Documentation/misc/hemppah-progradu/research_problems:1.19
--- gzz/Documentation/misc/hemppah-progradu/research_problems:1.18      Fri Jan 
17 08:05:14 2003
+++ gzz/Documentation/misc/hemppah-progradu/research_problems   Fri Jan 17 
09:09:27 2003
@@ -590,3 +590,30 @@
 
 2.8.3. Open questions 
 -how Xanadu links are saved: is there somekind of urn/uri/hash in the block's 
header, which refers to another block ?
+
+
+2.9 Models
+
+This sections presents formal models for various p2p architectures.
+
+2.9.1. Centralized
+-this category: Napster
+
+2.9.2. Decentralized, but structured
+-this category: DHTs, SWANs, Skip Graphs, hierarchical Gnutella's (superpeers, 
clusters)
+
+a) DHT
+(in our case, service is data block)
+-let S be the aggregate of all services s in system
+-let P be the aggregate of all peers (providers) p in system
+-let I be the aggregate of all identifiers i in system
+-let C be the aggregate of all coordinate points c in system
+-for each service s 'mathematical belongs to' S, there is a provider of the 
service, expressed as 'p = provider(s)'
+-service's identifier is defined as 'i = identifier(s)'
+-metric space is defined as a pair '(C,d)', where d is the distance between 
coordinate points c
+-hash function is defined as 'hash: K -> C', and coordinate point as 'c = 
hash(identifier(s))', which maps service, expressed by a identifier to 
coordinate point c in '(C,d)'
+-peer p is mapped onto a set C = {c 'mathematical belongs to' C: 'mathematical 
there exists at least one' s 'mathematical belongs to' S, c = 
hash(identifier(s)) 'boolean AND' (provider(s) = p)}
+
+2.9.2  Decentralized and unstructured
+-this category: Gnutella
+