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

[Hermanni Hyytiälä]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Hermanni Hyytiälä <address@hidden>      02/12/10 07:32:28

Modified files:
        Documentation/misc/hemppah-progradu: masterthesis.tex 
                                             progradu.bib 

Log message:
        DHT section updates

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/misc/hemppah-progradu/masterthesis.tex.diff?tr1=1.20&tr2=1.21&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/misc/hemppah-progradu/progradu.bib.diff?tr1=1.27&tr2=1.28&r1=text&r2=text

Patches:
Index: gzz/Documentation/misc/hemppah-progradu/masterthesis.tex
diff -u gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.20 
gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.21
--- gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.20       Tue Dec 
10 06:54:48 2002
+++ gzz/Documentation/misc/hemppah-progradu/masterthesis.tex    Tue Dec 10 
07:32:28 2002
@@ -210,17 +210,16 @@
 
 \section{Distributed Hash Tables}
 
-In DHT approach, each value is associated with a key in an m-bit virtual 
address space. The virtual 
+In DHT approach, each value is associated with a unique key (e.g. SHA-1 
\cite{fips-sha-1})in an m-bit virtual address space. The virtual 
 address space is partitioned into sections, which form adjoining regions of 
this address space. In general, 
 either a single computer or multiple computers is assigned to each section of 
the virtual address space. Each 
 computer is assigned one or more sections, and they maintains copies of those 
key-value bindings whose key values 
 lie within its assigned cell. This means, in general, that computer that hosts 
corresponding key-value pair, 
-is not owned by the user that decided to provide the resource to the 
community. Moreover, the allocation of the address 
+is not owned by the user that decided to provide the resource to the netowork. 
Moreover, the allocation of the address 
 space and the assigment of computers to sections is dynamic. Therefore, 
everytime when a node joins or 
 leaves the network, the address space is reallocated.
 
 
-
 \subsection{Plaxton Algorithm}
 Plaxton \cite{plaxton97accessingnearby} developed the first routing algorithm, 
which can be used with DHTs.
 The algorithm is not designed to be used in dynamic distributed systems, 
because Plaxton algorithm 
@@ -263,11 +262,18 @@
 Kademlia \cite{maymounkov02kademlia} is based on a XOR-based metric topology. 
In this approach, every query (message) exchanged conveys 
 useful contact information. Furthermore, Kademlia uses this information to 
send parallel query messages. XOR-metrics are used to calculate
 distances between points in key space. XOR is symmetric, allowing nodes to 
receive lookup queries from the same distribution of nodes 
-contained in the key space. Routing table contains ''contact buckets'', which 
allows to accommodate temporarily used nodes more 
+contained in the key space. Routing table contains ``contact buckets'', which 
allows to accommodate temporarily used nodes more 
 efficiently than other DHT approaches. For a system with $n$ nodes, Kademlia's 
algorithm routes in $O(log n)$ hops and requires 
 a routing table size of $O(log n)$.
 
+\subsection{Coral}
 
+Coral [NOTYETPUBLISHED] is based on a new abstraction called distributed 
sloppy hash table (DSHT) and is a layer on existing 
+lookup systems, such as Chord, CAN, Kademlia, Pastry and Tapestry. In contrast 
to original DHTs, Coral provides a lookup, which 
+is based on name (instead of hash value). Furthermore, Coral aims to avoid 
DHTs' hot spots and to find nearby data without querying 
+distant nodes. DSHTs sacrifice the consistency of DHTs to support both 
frequent fetches and frequent stores of the same hash table 
+key.  Moreover, the fundamental observation is that a node doesn't need to 
know every replicated location of a resource---it only 
+needs a single nearby copy.
 
 \section{Gnutella}
 \section{OceanStore}
Index: gzz/Documentation/misc/hemppah-progradu/progradu.bib
diff -u gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.27 
gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.28
--- gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.27   Tue Dec 10 
06:48:35 2002
+++ gzz/Documentation/misc/hemppah-progradu/progradu.bib        Tue Dec 10 
07:32:28 2002
@@ -1193,4 +1193,9 @@
        publisher = {ACM Press},
 }
 
-
+%SHA-1 secure hash standard
address@hidden(fips-sha-1,
+title = { FIPS PUB 180-1: Secure Hash Standard },
+organization = { NIST },
+year = { 1995 },
+)