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

[Hermanni Hyytiälä]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Hermanni Hyytiälä <address@hidden>      03/03/19 04:20:49

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

Log message:
        fixes, updates, improvements

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/misc/hemppah-progradu/masterthesis.tex.diff?tr1=1.155&tr2=1.156&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/misc/hemppah-progradu/progradu.bib.diff?tr1=1.112&tr2=1.113&r1=text&r2=text

Patches:
Index: gzz/Documentation/misc/hemppah-progradu/masterthesis.tex
diff -u gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.155 
gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.156
--- gzz/Documentation/misc/hemppah-progradu/masterthesis.tex:1.155      Tue Mar 
18 09:32:00 2003
+++ gzz/Documentation/misc/hemppah-progradu/masterthesis.tex    Wed Mar 19 
04:20:49 2003
@@ -82,54 +82,42 @@
 Peer-to-Peer systems have recently received considerable attention in both 
 academia \cite{projectirisurl} and industry \cite{p2pworkinggroup, jxtaurl} 
for a 
 number of reasons. The lack of centralization in Peer-to-Peer systems
-means that the participants can form a distributed system without any 
investment to centralized 
-hardware, which would coordinate it by sharing their services and connecting 
to each other directly
-\cite{couloris94distributedsystems}. The distributed and ad hoc nature of 
Peer-to-Peer improves 
-scalability and avoids single points of failure. Schollmeier 
\cite{schollmeier01p2pdefinition} 
-describes Peer-to-Peer system as a system of distributed entities that share 
their own services. 
-Peer-to-Peer systems can be characterized as distributed systems in which all 
communication is 
-symmetric and all participant entities have similar capabilities and 
responsibilities. 
-Each entity, i.e., \emph{peer}, may contribute services to the overall system.
+means that the participants can form a distributed system 
\cite{couloris94distributedsystems} 
+without any investment to centralized hardware by sharing their services and 
connecting to each 
+other directly. Peer-to-Peer systems can be characterized as distributed 
systems in which all 
+communication is symmetric and all participant entities have similar 
capabilities and responsibilities
+\cite{oram01harnessingpower}. Schollmeier \cite{schollmeier01p2pdefinition} 
describes Peer-to-Peer system as a system of 
+distributed entities that share their own services.
+Each entity, i.e., \emph{peer}, may contribute services to the overall system. 
The distributed 
+and ad hoc nature of Peer-to-Peer improves scalability and avoids single 
points of failure.  
 
 The Fenfire project is an attempt to build a hyperstructured, seamlessly 
interoperating desktop 
-environment. In the Fenfire, all data is stored as data blocks.  
-All data blocks have globally unique identifiers and they can be referred by 
pointer blocks. 
+environment. In the Fenfire, all data is stored in same format, i.e., data 
blocks.  
+Each data block have a globally unique identifier and it can be referred, by 
pointer blocks. 
 Other features of the Fenfire include innovative user 
-interfaces for viewing data and usage of Peer-to-Peer networking for network 
transparency. 
+interfaces for viewing data and the use of Peer-to-Peer networking for network 
transparency. 
 
-In this thesis, we evaluate existing Peer-to-Peer approaches and
-choose the best alternative to Fenfire's needs. 
+There are three research problems discussed in this thesis: first, finding the 
most efficient 
+way to locate and fetch Fenfire data blocks from a Peer-to-Peer network, when 
the block's 
+identifier is given. Second, we want to find the most efficient way to locate 
and fetch the most 
+recent Fenfire data block from a Peer-to-Peer network referred by a pointer. 
The third problem
+is similar to the second problem, except we want to locate and fetch the 
Fenfire
+data block, when date and or time range is given.
 
-We start by reviewing existing Peer-to-Peer approaches, algorithms and their 
key properties. 
-We observe that despite the great amount of proposed Peer-to-Peer systems, all 
systems fall either to loosely or 
+In this thesis, we evaluate existing Peer-to-Peer approaches and
+evaluate them to Fenfire's needs. We start by reviewing existing Peer-to-Peer 
approaches, 
+algorithms and their key properties. We emphasize that despite the great 
amount of proposed 
+Peer-to-Peer systems, we are able to classify \emph{all} systems either to 
loosely or 
 tightly structured approach. We also discuss open problems in 
 Peer-to-Peer systems and divide problems into three sub-categories: security, 
performance, and miscellaneous 
-problems.  
-
+problems. We attempt to comprehensively summarize existing algorithms and open 
problems in 
+Peer-to-Peer domain, this thesis doesn't give detailed information about 
reviewed algorithms nor
+open problems. More detailed information can be found from the references.
+ 
 Then, we give an overview of the Fenfire project, and evaluate Peer-to-Peer 
approaches to Fenfire's 
 needs. Finally, we propose simple but yet efficient methods to be used for 
data lookups in Peer-to-Peer 
 environment. 
 
-We attempt to comprehensively summarize existing algorithms and open problems 
in 
-Peer-to-Peer domain. However, this thesis is not meant to be detailed work. 
More detailed 
-information can be found from the references.
-
-There are three research problems discussed in this thesis. First research 
problem
-is finding the most efficient way to locate and fetch Fenfire data blocks from 
a 
-Peer-to-Peer network, where the block's identifier is given. Second, we want
-to find the most efficient way to locate and fetch the most recent Fenfire 
data block from a
-Peer-to-Peer network referred by a pointer block. The third problem
-is otherwise the same as the second problem, except we want to locate and 
fetch the Fenfire
-data block, where date and or time range is given.
-
-This thesis is structured as follows. In the next chapter, we give an overview 
of
-existing Peer-to-Peer approaches, algorithms and key differences between them. 
In chapter 3, we
-address open problems in Peer-to-Peer domain and divide problems into three
-sub-categories. Chapter 4 gives an overview of the Fenfire system. In chapter
-5, we evaluate existing Peer-to-Peer approaches with regard to the Fenfire 
system. 
-Finally, in chapter 6 we conclusions and future work.
-
-
 \chapter{Peer-to-Peer architectures}
 In this chapter we will give a brief history and overview of Peer-to-Peer 
networks, 
 review most the important Peer-to-Peer algorithms and list key differences 
between the 
@@ -137,7 +125,7 @@
 
 \section{Brief history and overview}
 
-The Internet was originally established in the late 1960s. The objective 
+The Internet was originally established in the late 1960s \cite{253741}. The 
objective 
 of the ARPANET-project was to share computers' resources among military 
computers
 around the United States. The most challenging purpose of ARPANET was to 
integrate 
 different kinds of existing network technologies with one common network 
architecture. 
@@ -145,25 +133,17 @@
 but rather as equal networking \emph{peers}. This could be seen as the 
starting point 
 of both the Peer-to-Peer concept and the Internet 
\cite{oram01harnessingpower}. 
 
-In subsequent years, the Internet became more restricted to client--server 
based 
-applications. In recent years, however, Peer-to-Peer systems have again 
emerged 
-in computing world. Indeed, Peer-to-Peer has had significant social and 
technical 
-attention in academia \cite{projectirisurl} and industry 
\cite{p2pworkinggroup, jxtaurl}. 
-The deceased Napster \cite{napsterurl}, 
-launched in 1999, was a new starting point for modern Peer-to-Peer computing. 
After
-Napster, hundreds of Peer-to-Peer systems have been developed and proposed. 
-
-A modern Peer-to-Peer system is composed of an \emph{application} level 
overlay network.
-Figure \ref{fig:application_level} illustrates the analogy of Peer-to-Peer 
network with
-regard to OSI model. Compared to ARPANET's Peer-to-Peer functionality, modern 
Peer-to-Peer systems
-are ad hoc, i.e., peers join and leave the system constantly in a dynamic 
manner. This
-fact constitutes challenging requirements for efficient construction and 
maintenance
-of the overlay network. Even more demanding tasks are performing efficient data
-lookup and maintaining security in a varying distributed environment. The most 
popular
-form of modern Peer-to-Peer computing is file-sharing. In this scenario, 
participants
-of Peer-to-Peer network share their file resources with other participants.
- This can be seen as a variant of distributed file system
-(e.g., \cite{levy90distributedfilesystems}). 
+The most popular form of modern Peer-to-Peer computing is file-sharing. In 
this scenario, 
+participants of Peer-to-Peer network share their file resources with other 
participants.
+This can be seen as a variant of distributed file system (e.g., 
\cite{levy90distributedfilesystems}). 
+A modern Peer-to-Peer system is composed of an \emph{application} level 
overlay network, i.e., 
+network operates at the application level and forms a logical network overlay 
on top of physical
+network. Figure \ref{fig:application_level} illustrates the Peer-to-Peer 
application level overlay network. 
+Compared to ARPANET's Peer-to-Peer functionality, modern Peer-to-Peer systems
+are \emph{ad hoc}, i.e., peers join and leave the system constantly. Thus, 
this property 
+poses challenges for efficient construction and maintenance
+of the overlay network, performing efficient data lookups and maintaining 
security in 
+a distributed environment. 
 
 \begin{figure}
 \centering
@@ -174,31 +154,30 @@
 
 
 
-In the development of modern Peer-to-Peer systems, lot of influence has been 
attained from 
-other research areas than computer science. Research has been conducted 
regarding 
-the self-organizing nature of complex networks \cite{albert-02-statistical, 
albert-00-tolerance, watts00dynamics}. 
-It is interesting to realize that chemical properties of biological cells, the 
Internet, ad hoc 
-Peer-to-Peer systems, and social networks have all in common that they 
self-organize based on the same 
-principles.  Furthermore, the association between social relationships among 
people 
-and Peer-to-Peer overlay topology has been studied recently 
\cite{watts00dynamics, kleinberg99small, nips02-Kleinberg}. 
-This insight is motivated by Milgram, who noticed that people are very 
effective in locating other people in a wide scale 
-based on local knowledge. This phenomenon is called as ''small-world 
phenomenon'' 
-\cite{milgram67smallworld}. As a consequence, many modern Peer-to-Peer systems
-have applied techniques outside of computer science when constructing and 
maintaining
-the application level overlay network.
+In the development of modern Peer-to-Peer systems, lot of influence has been 
derived from 
+outside of computer science. First, it is interesting to realize that chemical 
properties of biological cells, the Internet, ad hoc 
+Peer-to-Peer systems, and social network self-organize based on the same 
+principles \cite{albert-02-statistical, albert-00-tolerance, watts00dynamics}. 
 Second, the 
+association between social relationships among people and Peer-to-Peer overlay 
topology has been 
+studied recently \cite{watts00dynamics, kleinberg99small, nips02-Kleinberg}.
+This insight is motivated by Milgram \cite{milgram67smallworld}, who noticed 
that people are very effective in 
+locating other people in a wide scale based on local knowledge. This 
phenomenon is called as 
+''small-world phenomenon''. As a consequence, many modern Peer-to-Peer systems
+have applied similar techniques when constructing and maintaining the 
application level 
+overlay network.
 
-In the end, however, there are two main approaches in which all modern 
Peer-to-Peer
+In the end, however, we observe that there are only two approaches in which 
all modern Peer-to-Peer
 systems fall: the loosely structured approach and the tightly structured 
approach. In the loosely
 structured approach the construction and the maintenance of the overlay is 
controlled 
 loosely. This approach gives freedom for participating peers
 to perform certain tasks in a Peer-to-Peer network. On the other hand, the 
tightly structured
-approach has some rules, which all participating peers have to obey.
+approach the overlay is constructed determistically, which all participating 
peers have to follow.
 
 
 \section{Centralized}
 
 Napster\footnote{We decided to include Napster in this section only because it 
has
-historical value (see previous section).} \cite{napsterurl}  was designed to 
allow 
+historical value (see previous section).} \cite{yang02comparinghybrid}  was 
designed to allow 
 people to share music. It was a hybrid Peer-to-Peer file-sharing system, i.e., 
the search 
 index was centralized and the distribution of storage and serving of files was 
distributed. 
 Peers in the Napster network made requests to the central directory server to 
find 
@@ -209,13 +188,13 @@
 
 \section{Loosely structured}
 
-Gnutella \cite{gnutellaurl} is a well-known example of loosely structured 
overlay network. As in
-other pure Peer-to-Peer networks, no peer is more important than any other 
peer in the network.
+Gnutella \cite{ripeanu02mappinggnutella} is a well-known example of loosely 
structured overlay network. Gnutella
+is a pure Peer-to-Peer network as no peer is more important than any other 
peer in the network.
 The construction and maintenance of Gnutella network is extremely ad hoc, 
since participating
 peers can form the overlay network based on \emph{local} knowledge. Figure 
\ref{fig:gnutella_overlay}
 illustrates how peers form an overlay network. Initially, peer 1 creates the 
overlay, since
 it is the first participating peer. Then, repeatedly new peers join the 
network and connect to
-other peers in a random manner. Thus, Gnutella can be considered as a 
variation of \emph{scale-free
+other peers randomly. Thus, Gnutella can be considered as a variation of 
\emph{scale-free
 graph}\footnote{In scale-free graphs (also known as power-law graphs) only a 
few peers have high number of neighbor 
 links and the majority of peers have low number of neighbor links.}.
 
Index: gzz/Documentation/misc/hemppah-progradu/progradu.bib
diff -u gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.112 
gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.113
--- gzz/Documentation/misc/hemppah-progradu/progradu.bib:1.112  Fri Mar 14 
07:44:58 2003
+++ gzz/Documentation/misc/hemppah-progradu/progradu.bib        Wed Mar 19 
04:20:49 2003
@@ -960,7 +960,7 @@
        title = {Distributed Systems: Concepts and Design},
        author = {George Coulouris and Jean Dollimore and Tim Kindberg},
        year = {1994},
-       publsiher = {Addison-Wesley},
+       publisher = {Addison-Wesley}
 }
 
 @book{foster98grid,
@@ -2146,4 +2146,27 @@
        key = {Google},
        title = {Google},
        howpublished = {http://www.google.com}
+}
+
address@hidden,
+       author = {Barry M. Leiner and Vinton G. Cerf and David D. Clark and 
Robert E. Kahn and Leonard Kleinrock and Daniel C. Lynch and Jon Postel and 
Lawrence G. Roberts and Stephen S. Wolff},
+       title = {The past and future history of the Internet},
+       journal = {Communications of the ACM},
+       volume = {40},
+       number = {2},
+       year = {1997},
+       issn = {0001-0782},
+       pages = {102--108},
+       doi = {http://doi.acm.org/10.1145/253671.253741},
+       publisher = {ACM Press},
+}
+
+
address@hidden,
+       author = {Marshall T. Rose},
+       title = {The open book: a practical perspective on OSI}, 
+       publisher = {Prentice-Hall},
+       Pages = {651},
+       Year = {1990},
+       ISBN = {0-13-643016-3} 
 }