/[gzz]/gzz/Documentation/misc/hemppah-progradu/masterthesis.tex
ViewVC logotype

Diff of /gzz/Documentation/misc/hemppah-progradu/masterthesis.tex

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.21 by hemppah, Tue Dec 10 12:32:28 2002 UTC revision 1.22 by hemppah, Tue Dec 10 12:52:20 2002 UTC
# Line 234  Plaxton's algorithm routes in $O(log n)$ Line 234  Plaxton's algorithm routes in $O(log n)$
234  \subsection{Tapestry}  \subsection{Tapestry}
235  Tapestry \cite{zhao01tapestry} is a adaption of Plaxton's algorithm \cite{plaxton97accessingnearby}. Tapestry  Tapestry \cite{zhao01tapestry} is a adaption of Plaxton's algorithm \cite{plaxton97accessingnearby}. Tapestry
236  routes queries with path lengths of $O(log n)$, and each node, for a systems with $n$ nodes, maintains routing table  routes queries with path lengths of $O(log n)$, and each node, for a systems with $n$ nodes, maintains routing table
237  size of $O(log n)$.  size of $O(log n)$. When a node leaves or joins to network,  $O(log^2 n)$ messages are required.
238    
239  \subsection{Pastry}  \subsection{Pastry}
240  In Pastry \cite{rowston01pastry}, the key space is considered as a virtual circle. Each node is responsible for keys  In Pastry \cite{rowston01pastry}, the key space is considered as a virtual circle. Each node is responsible for keys
241  which are closest numerically. The neighbors consist of leaf set, which is the set of $|L|$ closest nodes. In addition,  which are closest numerically. The neighbors consist of leaf set, which is the set of $|L|$ closest nodes. In addition,
242  Pastry has another set of neighbors randomly spread out in the key space for more efficient routing. As in Plaxton approach,  Pastry has another set of neighbors randomly spread out in the key space for more efficient routing. As in Plaxton approach,
243  Pastry also forwards the query to the neighbor which have the longest shared prefix of the key. Pastry routes within  Pastry also forwards the query to the neighbor which have the longest shared prefix of the key. Pastry routes within
244  the pathlength of $O(log n)$ and each node has $O(log n)$ neighbors.  the pathlength of $O(log n)$, each node has $O(log n)$ neighbors and departure or joining of node requires $(log^2 n)$ messages.
245    
246  \subsection{CAN}  \subsection{CAN}
247  In the CAN model \cite{ratnasamy01can}, nodes are mapped into a virtual $d$-dimensional coordinate key space. Each node  In the CAN model \cite{ratnasamy01can}, nodes are mapped into a virtual $d$-dimensional coordinate key space. Each node
248  is associated with a hypercubal blocks of this keyspace and every block keeps information on its immediate hypercubal  is associated with a hypercubal blocks of this keyspace and every block keeps information on its immediate hypercubal
249  neighbors. In CAN, nodes have $O(d)$ neighbors and expected pathlengths are $O(dn^\frac{1}{d})$. Setting  neighbors. In CAN, nodes have $O(d)$ neighbors and expected pathlengths are $O(dn^\frac{1}{d})$. Node insertion or deletion affects
250  $d = log_2(n)/2$, CAN provides similar scalability as Plaxton approach.  $O(number of dimensions)$ existing nodes. Setting $d = log_2(n)/2$, CAN provides similar scalability as Plaxton approach.
251    
252  \subsection{Chord}  \subsection{Chord}
253  Chord \cite{stoica01chord} uses virtual circle as the key space. As Pastry, Chord also threats node's neighbors as leaf sets.  Chord \cite{stoica01chord} uses virtual circle as the key space. As Pastry, Chord also threats node's neighbors as leaf sets.
254  However, in Chord, there are two sets of neighbors: each node has a successor list of k nodes which immediately follows the node  However, in Chord, there are two sets of neighbors: each node has a successor list of k nodes which immediately follows the node
255  in the key space. For better efficiency, each node has additional finger list of $O(log n)$ nodes placed around the key space.  in the key space. For better efficiency, each node has additional finger list of $O(log n)$ nodes placed around the key space.
256  In a $n$ node network, each node maintains information about $O(log n)$ neighbors, and a lookup is performed within $O(log n)$  In a $n$ node network, each node maintains information about $O(log n)$ neighbors, and a lookup is performed within $O(log n)$
257  hops. Additionally in Chord, a join or leave requires $O(log^2 n)$ messages.  hops. Additionally in Chord, a node join or leave requires $O(log^2 n)$ messages.
258    
259    
260  \subsection{Kademlia}  \subsection{Kademlia}

Legend:
Removed from v.1.21  
changed lines
  Added in v.1.22

savannah-hackers-public@gnu.org
ViewVC Help
Powered by ViewVC 1.1.26