Peer-to-Peer Systems

1
Peer-to-Peer Systems

• ????µ?a ??ßa
• ???? ????ß??a
• ?a??a ???st?d????d??

2
Tet???-????t??? st???e?a t?? P2P

• Tet???
• Se a?t??es? µe ta pa?ad?s?a?? µ??t??a t??
  s?st?µ?t?? client-server ta a??e?a sta P2P
  s?st?µata ap????e???ta? st??? ??µß???, ?p?te ?
  a?a??t?s? de? ep?ßa???e? ??a? ?e?t???? server
• ??e? µ???? s?et??? ??st?? ?atas?e???, af?? de?
  apa?te? st?? pe??ss?te?e? pe??pt?se?? e?d???
  p??s?et? ????sµ??? ?a? ?????
• ????st?a se pe??pt?s? ap?t????? ??µß??
• ??te??? d?aµ???asµ?? p????
• ??t?-??????s?
• ???s????p?s? f??t???
• ?????µ?a

3
Tet???-????t??? st???e?a t?? P2P

• ????t???
• ??µ?????e? d?s????a st?? a?e??es? ?a?
  s??t???s?-e??µ???s? t?? p????f???a? p?? ß??s?eta?
  d?aµ???asµ??? st??? ?p?????st?? t?? d??t???
• ?e? e??a? d??at? p??t?te ? e??es? ap??t?s??
  pa???? p?? p??a??? ?a ?p???e?
• ???sf??e? ?aµ??? asf??e?a, p?? ?fe??eta? st??
  ap??s?a ?e?t????? s?µe??? e?????? ?a? st?
  d?asp??? t?? p????f???a?
• ?a P2P s?st?µata s?ed?????ta? ?????? ??a ?a
  efa?µ?st??? se t?p??? d??t?a pe?????sµ????
  p?????? ??µß??, e?a?t?a? t?? ad??aµ?a? ???µ???s??
  p????? ap? a?t?

4
?fa?µ???? t?? P2P

• ??aµ???asµ?? a??e???(file-sharing)
• ??ad??t?a?? ?a????d?a
• ??aµ???asµ?? F?t???af??? p???d??state?
  e??t?se?? d?ast?µat??
• ?ata?eµ?µ???? ?p?????sµ??, p.?. p?????s? ?a????
• ????ap??? e?p?µp?? t?? ?d??? ded?µ????(Multicasts)

5
??d?af????ta s?st?µata /a??????µ??

• ? ???s? s??t?µe?se?? µeta?? t?? ??µß?? p?? ?????
  ????? e?d?af????ta
• LSI (Latent Semantic Indexing) ?µad?p??e?
  s?µas???????? ?µ??a ded?µ??a
• Routing Indices d??µ?????s? t?? e??t?s?? st???
  ??µß??? p?? µe µe?a??te?? p??a??t?ta ?a pa??????
  apa?t?se??
• Associative Search - ?µad?p???s? t?? ??µß?? µe
  ß?s? t? pe??e??µe?? t?? ded?µ???? t???
• Mercury e??t?se?? d?ast?µat?? p?????
  ?????sµ?t??

6
?a??te?? Paper

• Routing Indices
• ?d?a d??µ?????s? t?? e??t?s?? se e?e????? t???
  ?e?t??e? p?? e??a? p?? p??a?? ?a pe???????
  apa?t?se?? a???????s? ?e?t????
• Se s??s? µe t? ???s? ????? e?d?? e??et?????
  ?pe?te?e? ???? t?? µ????? µe?????? t?? index
  (a?????? t?? p?????? t?? ?e?t???? ?a? ??? t??
  p?????? t?? ded?µ????)
• ?a RIs ap?d?d??? ?a??te?a se power-law s?st?µata
• ? ???s? t?? RIs se µ? d?µ?µ??a s?st?µata ep?f??e?
  ?a??te?? ap?d?s? ap? ?t? ? µ? ???s? index p.?. se
  s?????s? µe p??µµ??a ????te?a µ???µata

7
?e????t??? d???e??

• ??st?p???s? ???e?t???t?ta? d?s???? ????
  a????µ?a?
• ?sf??e?a ?a??ß????? ???ste? p?? ep??e????? ?a
  ?atast?????? t? d??t??
• ??asf???s? e?????t?ta? ?a? ??µ?µ?t?ta? t??
  ded?µ????
• ??t?µ?s? t?? ?p??es??? (s??e?sf???) p?? pa???e?
  ???e ??µß?? st? d??t??