Declarative Overlays

1
Declarative Overlays

• ??t??? ?a???t??, Intel Research Berkeley
• se s??e??as?a µe Tyson Condie (UCB), David Gay
  (IRB),Minos Garofalakis (IRB), Joseph M.
  Hellerstein (UCB),Boon Thau Loo (UCB), Raghu
  Ramakrishnan (UW),Sean Rhea (MIT/IRB), Timothy
  Roscoe (IRB),Atul Singh (Rice), Ion Stoica (UCB)

2
????t??? ?p?st??µata?

• ??t??? ?a???t??, Intel Research Berkeley
• se s??e??as?a µe Tyson Condie (UCB), David Gay
  (IRB),Minos Garofalakis (IRB), Joseph M.
  Hellerstein (UCB),Boon Thau Loo (UCB), Raghu
  Ramakrishnan (UW),Sean Rhea (MIT/IRB), Timothy
  Roscoe (IRB),Atul Singh (Rice), Ion Stoica (UCB)

3
?p?st??µata ?a?t??

• ?p?st??µa t? ?p?s?st?µa d??µ?????s?? ?a?
  p?????s?? µ???µ?t?? se ???e ?ata?eµ?µ??? s?st?µa

4
?p?st??µata ?a?t??

• ?et?d?s? pa??t??
• Internet routing
• multicast
• RON
• ?et?d?s? pe??e??µ???? (content delivery)
• CDNs (p.?., Akamai)
• file sharing (p.?., Kazaa)
• DHTs (p.?., Chord, Pastry, )
• ??????s?
• ?ata?eµ?µ??? epe?e??as?a epe??t?se?? (p.?., PIER)
• t? MapReduce t?? Google
• Enterprise
• Microsoft Exchange

? ??a???s? sta ?ata?eµ?µ??a S?st?µata ??e???eta?
ta ?p?st??µata
5
??s???? ? ?p?st??s?...

• ???e efa?µ??? ep?st??s?? ??e? t?? d???? t??
  a????e?
• Low latency, high bandwidth, high reliability,
  tolerance to churn, anonymity, long-term
  preservation,
• ?p?te ??a ???e efa?µ??? p??pe?
• ?a ß?e?? t?? s?st?? ?d??t?te? ? ????? s???????
  e????a
• ???? s?st??? a??????µ??? ? ????? a??????µ??
• ?a t??? ???p???se?? ? ?sfa?µ??? ???p???s?
• ?a ???µ?se?? pa?aµ?t???? ? ????t??? timeouts
• ?a e????e?? t? ap?t??esµa ? ?e????? ap?t???e?
• Debugging! ? ?s??????? e?d?s??p?s?
• ?a? ?a??, p????? f???? ? ????t?t??? ßa?eµ??a

6
??s???? ? ?p?st??s?...

• ???e efa?µ??? ep?st??s?? ??e? t?? d???? t??
  a????e?
• Low latency, high bandwidth, high reliability,
  tolerance to churn, anonymity, long-term
  preservation,
• ?p?te ??a ???e efa?µ??? p??pe?
• ?a ß?e?? t?? s?st?? ?d??t?te? ? ????? s???????
  e????a
• ???? s?st??? a??????µ??? ? ????? a??????µ??
• ?a t??? ???p???se?? ? ?sfa?µ??? ???p???s?
• ?a ???µ?se?? pa?aµ?t???? ? ????t??? timeouts
• ?a e????e?? t? ap?t??esµa ? ?e????? ap?t???e?
• Debugging! ? ?s??????? e?d?s??p?s?
• ?a? ?a??, p????? f???? ? ????t?t??? ßa?eµ??a

??s???? d???e?????pe? ?a t?? ?????µe µe t? ????
???e f???
7
? ?as???? µa? St????

• ?a d?e????????µe t?? a??pt??? ep?st??µ?t??
• ?ste ?a as?????µaste µe a??????µ??? ?a?
  p??t?????a, ??? µe t?? ?ept?µ??e?e? t??
  ???p???s??...
• ???a?e?a ???????? a??pt???? ep?st??µ?t??
• ???d?a??af? t?? ep?st??µat?? se ????? ep?ped?
• ??t?µat? µet?f?as? t?? p??d?a??af?? se p??t??????
• ??t?µat? e?t??es? t?? p??t???????
• ?p? p?e???? ap?d?s??, p?µe ??a ??a? ?a???, ???
  ??a ???sta
• ?p?ta?????µe t?? epa?a?aµßa??µe?? s?ed?ast???
  d?ad??as?a
• ???et??µ????µe t? ?daf?? ??a ?e????a?t??? ? ?a?
  a?t?µat? ße?t?st?p???s? se ep?µe?? st?d??

?,t? p?t??e ? s?es?a?? epa??stas? ?a? ? SQL ??a
t?? ß?se??, a??? ??a ta d?ad??t?a
8
? ???? µa? ???s????s? P2

• ?e?????µaste t??? ?ata?eµ?µ????? a??????µ??? sa?
  µ?a ??? (database view) t?? µetaßa???µe???
  s?st?µat??
• ??a? µetas??µat?sµ?? t?? ?eµe???d??? ?at?stas??
• ??at????µe t?? ??? sa? µ?a s??e?? ?ata?eµ?µ???
  epe??t?s?
• ?a??? ??p???? ??µß?? ap?t????????, ?e??e??
  d?a??pt??ta?, ? p????sµ?? a????e?, ??p.

9
?? ???t??? ?ed?µ???? t?? P2

• ?ata?eµ?µ??? ?at?stas? (soft state) ap????e?eta?
  ef?µe?a se s?es?a???? p??a?e?
• route(Src, Dst, FirstHop)
• ?? ap????e?s?µ? p????f???a p.?., µ???µata
  µetad?deta? se ???? p?e??d?? (tuple streams)
• message(Src, Dst)
• ?a? st?? d?? pe??pt?se??, ta ded?µ??a ?????
  s???e???µ??? s??µa

10
?a??de??µa???µ?????s? ?a?t?????

• ??µß?? se da?t????
• ???a??µ???? µe ß?s? t?? ta?t?t?t? t???
• ?a???a? ??????e? t? d??d??? t??
• ?ed?µ??a ap????e???ta? st? da?t???? µe ß?s? t?
  ??e?d? t???
• ?pe?????? ??µß?? e??a? ? d??d???? t?? ded?µ????

11
?a??de??µa???µ?????s? ?a?t?????

• ??µß?? se da?t????
• ???a??µ???? µe ß?s? t?? ta?t?t?t? t???
• ?a???a? ??????e? t? d??d??? t??
• ?ed?µ??a ap????e???ta? st? da?t???? µe ß?s? t?
  ??e?d? t???
• ?pe?????? ??µß?? e??a? ? d??d???? t?? ded?µ????

12
?a??de??µa???µ?????s? ?a?t?????

• ??? ß??s?? ??a s???e???µ??? ded?µ??? µe ß?s? t?
  ??e?d? t??
• ???????µ??
• n.lookup(k)
• if k in (n, n.successor)
• return n.successor
• else
• return n.successor. lookup(k)

13
?a??de??µa???µ?????s? ?a?t?????

• n.lookup(k)
• if k in (n, n.successor)
• return n.successor
• else
• return n.successor. lookup(k)
• ?at?stas? ??µß??
• node(Addr, N)
• successor(Addr, Succ, SAddr)
• ????µata
• lookup(Addr, Req, K)
• response(Req, K, SAddr)

14
?e?d???d??a? O? ?pe??t?s?

• n.lookup(k)
• if k in (n, n.successor)
• return n.successor
• else
• return n.successor. lookup(k)
• ?at?stas? ??µß??
• node(Addr, N)
• successor(Addr, Succ, SAddr)
• ????µata
• lookup(Addr, Req, K)
• response(Req, K, SAddr)

• send response(Req, K, SAddr) to Req
• when lookup(NAddr, Req, K) at NAddr
• and node(NAddr, N),
• and succ(NAddr, Succ, SAddr),
• and K in (N, Succ

15
?e?d???d??a? O? ?pe??t?s?

• n.lookup(k)
• if k in (n, n.successor)
• return n.successor
• else
• return n.successor. lookup(k)
• ?at?stas? ??µß??
• node(Addr, N)
• successor(Addr, Succ, SAddr)
• ????µata
• lookup(Addr, Req, K)
• response(Req, K, SAddr)

• send response(Req, K, SAddr) to Req
• when lookup(NAddr, Req, K) at NAddr
• and node(NAddr, N),
• and succ(NAddr, Succ, SAddr),
• and K in (N, Succ
• send lookup(SAddr, Req, K) to SAddr
• when lookup(NAddr, Req, K) at NAddr
• and node(NAddr, N),
• and succ(NAddr, Succ, SAddr),
• and K not in (N, Succ

16
?p? ?pe??t?s? Se ??t??es?

• ??p??? pa?ad?s?a?? p??ß??µa ß?se??
• ???d?a??af? µetaf???eta? a?t?µata se ???f? ????
  ded?µ???? (dataflow graph)
• ??µß?? t?? ???f?? e??a? ?p?????st??? st???e?a
  ??aµµ??a se C (µ??????? µe t? Click)
• ?a st???e?a ???p?????
• S?es?a???? te?est?? (joins, selections,
  projections)
• ?e?est?? ???? (multiplexers, demultiplexers,
  queues)
• ???t?a???? te?est?? (congestion control, retry,
  rate limitation)
• ?a? d?as??d???ta? µ?s? as???????? t?p?p???µ????
  ???? (push ?a? pull)
• ? ???f?? e?te?e?ta? ap? ??a ?e???? d?e?pe?a??t?
  (p.?., FIFO e?t??es? ? ???e?)

17
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

18
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

19
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

20
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

21
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

22
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

23
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

24
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

25
?et?f?as? se G??f? ????

• Send response(Req, K, SAddr) to Req, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr, N)
  and succ(NAddr, Succ, SAddr) and K in (N, Succ.
• Send lookup(SAddr, Req, K) to SAddr, when
  lookup(NAddr, Req, K) at NAddr and node(NAddr,
  N), and succ(NAddr, Succ, SAddr) and K not in (N,
  Succ.

26
????te?t????? t?? S?st?µat??
27
P2
???d?a??af? t?? ?ata?eµ?µ???? s?st?µat?? se
??p??a ???ssa epe??t?se??
?e????af? t??ep?st??µat??
?et?f?as? p??d?a??af?? se ße?t?st?p???µ??? ???
ded?µ????
??t??es? ???f?? ???? ??a t? d?at???s? t??
ep?st??µat??
??e???µe?apa??ta
??se???µe?apa??ta
28
G??sse? ???d?a??af??

• G??ssa ???? ded?µ????
• ??t?st???? µe t? ???ssa t?? Click
• ????e? ?p?????st??? st???e?a ?a? ta d?as??d?e?
• ????t??? ???ssa (OverLog)
• ?a?ap??s?a t?? Datalog, ?ata?eµ?µ???, µe a??a???
  ?at?stas??
• ltap?t??esµagt - ltµ???µagt, ltp???p??es?1gt,
  ltp???p??es?2gt, , ltp???p??es??gt.
• ??p???µ?a (location specifiers) t?p??et??? ???e
  p?e??da st?? ??µß? t??
• response_at_Req(K, SAddr) -lookup_at_NAddr(Req, K),
  node_at_NAddr(N),succ_at_NAddr(Succ, SAddr), K in (N,
  Succ.
• ???µa t?? d??
• ?????? µe OverLog, µet? ?ept?µe?e?? a??a??? st?
  ???f? ap e??e?a?

29
?e?t??????? ???t??? t?? OverLog

• ?p?? µe ???e ?????? ???ssa, ? µa?e?a ???e?ta?
  st?? e??p???s? µetaß??t??
• message_at_H(H, D) - route_at_S(S, D, H), message_at_S(S,
  D).
• ?????te?? ep?ped? ??f?as?? a??? d?s????te??
  µet?f?as? se e?te??s?µ? ??d??a
• ????
• ?e???? ?????? ap? ?p?????sa ??e??a
• Stat???? ?a? d??aµ???? ??e????, te?µat?sµ??,
  ße?t?st?p???s?, ??p. ??p.

30
??a ????p????te?? ?a??de??µa

• ?????? p??d?a??af? t?? Chord (MIT/UCBerkeley)
• 46 ?a???e? OverLog
• 212 ?p?????st??? st???e?a
• ?d?e? ?d??t?te?
• ???a???µ??? d??µet??? t?? d??t???
• ???a???µ??? ?at?stas? a?? ??µß?
• S??ep?? d??µ?????s?, a??µ? ?a? µe µetaßa???µe??
  p????sµ?
• ??a? ?a???
• 4x d??t?a?? ?a??st???s? (latency) se s??s? µe t?
  ?e???p???t? Chord
• ????? ???a pa?ade??µata
• Multicast, gossip, flooding, PAXOS

31
S?????s? µe t? Chord se ?aµ??? ?p?p?d? (C)
32
????? st??µ??...

• ???d?a??af? ep?st??µ?t?? sa? s??e?e??
  ?ata?eµ?µ??e? epe??t?se??
• ?et?f?as? se ???f? ???? ded?µ????
• ??t??es? t?? ???f?? e?te?e? t? ep?st??µa
• ?p?de?t? ? ap?d?s? t?? ap?te??sµat??
• ????
• ?ta? ap??t?? ??a s?st?µa epe?e??as?a?
  ?ata?eµ?µ???? epe??t?se??, p??? ?a?? ?p??ta?

33
???ta?? ??d?s??p?s? ?ata?eµ?µ???? S?st?µ?t??

• µe t??? Peter Druschel (Rice/Max Planck), Timothy
  Roscoe (IRB),Atul Singh (Rice)

34
??d?s??p?s?!

• ??p??s?p?s? ?p?????sµ?? sa? ???f?? ???? ded?µ????
• ???? a??µesa se st???e?a µp????? ?a pa?at???????
• ? ?at?stas? ???e st???e??? µp??e? ?a pa?at????e?

35
Stat??? ??d?s??p?s?

• ??p??s?p?s? ?p?????sµ?? sa? ???f?? ???? ded?µ????
• ???? a??µesa se st???e?a µp????? ?a pa?at???????
• ? ?at?stas? ???e st???e??? µp??e? ?a pa?at????e?

36
??te?est??? ??d?s??p?s?

• ? e?t??es? t?? ???f?? ???? µp??e? ?a pa?at????e?
• ?p?te ??a? ?a???a? pa???e? ??p??? ap?t??esµa,
  µp??? ?a ??at?s? t?? e?s?d??? (µ???µata ?a?
  p???p???se??) p?? d??a??????? t? ap?t??esµa
• exec(RuleID, Input, TimeIn, Output, TimeOut)

37
?ata?eµ?µ??? ????? sa?t??

• ???t???
• ???e e?d?s??p??? pa?at???s? e??a? p??a?a? t?? P2
• ?p??? ?a ????? epe??t?se?? p??? st?? ?at?stas?
  t?? s?st?µat?? ?a? st?? e?d?s??p???? ????
• ?p??? ?a ????? epe??t?se?? e?????? (p.?., ??a
  debugging) st?? ?d?a ???ssa p??d?a??af??!
• ? efa?µ??? de ??e???eta? ?a staµat?se?, ? ?a
  ???e? ?a? ?t? e?d?s??pe?ta?

38
Debugging

• ???ta??? ??e???? ?d??t?t?? t?? ep?st??µat?? ??a
  ?ata?eµ?µ??? watch point
• ???e ??µß?? ??e? t? p??? ? p??????µe???? st?
  ???f?
• ?a???a? ??µß?? de? pa???d??µe? st??? p??a?e?
  d??µ?????s??
• ? d??µ?????s? e??a? s??ep??
• ?a?a???????s? t?? e?t??es?? se ep?ped?
  ?e?d???d??a ??????? ß?µat?sµ??
• G??f?? a?t??t?ta? (causality graph) µ?a?
  ap?t???µ???? a?t?s??
• ??t?p?sµ?? ap?t???µ???? a?t?se?? ????
  pa???d??µ???? p?????? d??µ?????s??
• ??at???s? p???p????? ??e?? t?? t?????t??
  s?st?µat??
• S??ep? st??µ??t?pa t?? s?st?µat?? (consistent
  snapshot)
• ?pe??t?se?? p??? st? st??µ??t?p?, p.?., ??a
  sta?e??? ?d??t?te?
• ?p????e?s? ?ata?eµ?µ???? st??µ??t?p?? p?? p??????
  ??p??e? ?????? ?d??t?te?
• ?sf??e?a, a?t?stas? se ap?t???e?, ??p.
• Auditing for equivocation

39
S?stat??? ??a ???t?????a ?etaf????

• with Tyson Condie (UCB),Joseph M. Hellerstein
  (UCB),Sean Rhea (MIT/IRB),Timothy Roscoe (IRB)

40
S?stat??? ??a ???t?????a?

• ?????s? p??t??????? µetaf???? se ßas??? d?µ???
  st???e?a p?? µp????? ?a epa?as?sta???? µe
  d?af??et????? t??p??? a?????a µe t?? efa?µ??? ?
  t?? ?at?stas? t?? d??t???

41
S??t?µ? ?st????? S?stat???? ??a ???t?????a

• ?? epe?e???sa? st? pa?e????, ?a? p?t??a?!
• ?e?t??????? s?st?µa x-Kernel
• ????e? p??t?????a ?? a?t??e?µe?a, ta ?p??a
  µp????? ?a d?as??de???? ??a ?a pa?????? p??
  p???p???e? ep????????a??? ?p??es?e?
• G??ssa p????aµµat?sµ?? Morpheus
• ??t??e?µe??st?ef?? p????aµµat?st??? ?p?st?????
  ??a a?t??e?µe?a p??t???????
• Stat???? ße?t?st?p???se?? (?at? t? µet?f?as?) t??
  pa?a????t?? p??t???????
• G??ssa p????aµµat?sµ?? Prolac
• ??f?ast??? ???ssa ??a t? s????af? ?????????
  p??t???????
• ???? ?µ??, ?a?e?? de ????st??e ??a ta
  ap?te??sµata
• ?? pe??ss?te?e? efa?µ???? ?ta? µ?a ?a?? µe ta
  s?????, µ????????? p??t?????a ap? s?µe?? se
  s?µe?? (point-to-point)
• TCP, UDP, DCCP, etc.

42
?? ???a?e t??a?

• ?p?st??µata!
• ?? ??µß?? pa????? ????? t??? ??????
• client, server, d??µ?????t?
• ???µ?????s? st? ep?ped? t?? efa?µ???? s?µa??e?
  ?t? µp??e? ?a µ?? ???? t?? te???? p?????sµ? e???
  µ???µat??
• ?p????????a 1? ? ?? e??a? ? ?a???a?, ??? p????
  ? e?a??es?
• ?e???? pa?ade??µata a?????????

43
?pa?aµet?d?s? st? d??µ?????s?
44
?pa?aµet?d?s? st? d??µ?????s?
45
?pa?aµet?d?s? st? d??µ?????s?
46
S??a????st??? ?p?s?µf???s?
47
S??a????st??? ?p?s?µf???s?
48
??p???t?s? ??d??µes?? ???µ??
49
??p???t?s? ??d??µes?? ???µ??
50
??p???t?s? ??d??µes?? ???µ??
51
??a G????ta? µe t? P2

• ?e s?ed?? tet??µµ??? t??p?
• ? ???f?? ???? de?µ???? s???e?t???e? ??? t??
  p???p????t?ta
• ??µß?? a?t?st?????? se af???µ??? ?e?t???????t?ta
  ??a s???e???µ??? s??p?
• ?p??? ?a staµat?s?, ?a epa?as??d?s?, ?a? ?a
  epa?e?????s? ???? ??a ?a a????? ???ta?? t?
  ?e?t?????a t?? s?st?µat??
• ??s?ast???, afa????µe t? d?a????st??? a??µesa
  st?? efa?µ??? ?a? st? p??t?????? µetaf????
• ?a ep?peda pa?aµ????? st?? p??d?a??af?
• ???? afa?????ta? st?? a?t?µat?p???µ??? ???p???s?

52
??se??

• ?a???e? µeta??af?? t?? ???f?? ????
• ?p??? ?a a?ta????? ??a select µe ??a project
• ?p??? ?a afa???s? e?d??µes? µ??µ?, a? ?p???e?
  ???? p?? p????e?ta?
• ????t??? ???ssa ??a t? ep?ped? µetaf????
• ?a? µet?, µet?f?as? t?? ?????? ?d??t?t?? st?
  ???f? ????, p.?.
• ???e?e µ???µata p??? t?? ?d?? p?????sµ? st? ?d??
  pa??t?
• ?? µa?e?e?? pe???d??? µ???µata, p.?.,
  keepalives
• ??t?µat? pa?a???? ???f?? ????
• ?e?t?st?p???µ???? µe ß?s? t? ??st?? p???ap???
  e?a??a?t???? (cost-based view selection)
• ???????det? p??ß??µa µe t?? e?d?s??p?s?

53
?a?a??t?...
54
?e??????

• ? e?????? t?? ?ata?eµ?µ???? s?st?µ?t?? pe??? µ?sa
  ap? ta d??t?a?? ep?st??µata
• ??p?? p??pe? ?a d?e????????µe t?? a??pt???
  ep?st??µ?t??
• ?e t? P2, µp???
• ?a p??d?a????? ep?st??µata se µ?a ??t?, ??????
  ???ssa
• ?a µetaf??s? t?? p??d?a??af? se ???f? ????
  ded?µ????
• ?a e?te??s? t? ep?st??µa sa? µ?a ?ata?eµ?µ???
  epe??t?s?
• ??a stad?a?? µet?ßas? ap? t?? ß?a??? t?? µ???st??
  ap?d?s?? st?? e????? d?µ????????t?ta st? ???? t??
  ?ata?eµ?µ???? s?st?µ?t??

55
????s?? ?e??? ??e??a?

• ? s?st? ???ssa ??a ?????? ?d??t?te?
• ???a e??a? ta ßas??? d?µ??? st???e?a
• ?p??? ?a µetaf??s? t? ?st? ??a ???a???µ???
  ep?st??µa
• Stat???? ??e????
• ??? µp??? ?a ap?de??? ?t? ? a??????µ?? µ??
  a?t?st???e? s?µas???????? se ??a p????aµµa
  OverLog
• ?e?µat?sµ??, s?????s?, ??p
• ?e?t?st?p???s?
• ???e? te?????? ap? t?? ?ata?eµ?µ??e? ß?se??
  (e.g., River) d???e????
• ???a d??aµ??? stat?st??? st???e?a ??e????µa? ??a
  ße?t?st?p???s?
• ???e? ße?t?st?p???se?? (p???ap??? epe??t?se??,
  magic sets, )
• ??a??a?t??? pe??ß?????ta
• ?pe?e??ast?? d??t??? (p.?., ??a t?? ???p???s?
  d??µ?????t??)
• ?pe?e??ast?? µe p?????? ?p?????st????? p????e?

56
S?et???? ??µ?s?e?se??

• Churn as Shelter. Tyson Condie, Varun Kacholia,
  Sriram Sankararaman, Joseph M. Hellerstein and
  Petros Maniatis. Network and Distributed System
  Security (NDSS), 2006. To appear.
• Finally, a Use for Componentized Transport
  Protocols. Tyson Condie, Joseph M. Hellerstein,
  Petros Maniatis, Sean Rhea, and Timothy Roscoe.
  Proceedings of ACM/IEEE HotNets IV, 2005.
• Implementing Declarative Overlays, Boon Thau Loo,
  Tyson Condie, Joseph M. Hellerstein, Petros
  Maniatis, Timothy Roscoe, and Ion Stoica.
  Proceedings of the 20th ACM Symposium on
  Operating Systems Principles (SOSP), October
  2005.
• The Architecture of PIER an Internet-Scale Query
  Processor. Ryan Huebsch, Brent Chun, Joseph M.
  Hellerstein, Boon Thau Loo, Petros Maniatis,
  Timothy Roscoe, Scott Shenker, Ion Stoica and
  Aydan R. Yumerefendi. Proceedings of the 2nd
  Conference on Innovative Data Systems Research
  (CIDR), January 2005.
• Providing Packet Obituaries. Katerina Argyraki,
  Petros Maniatis, David Cheriton, Scott Shenker.
  Proceedings of ACM/IEEE HotNets III. November
  2004.
• Design Considerations for Information Planes.
  Brent Chun, Joseph M. Hellerstein, Ryan Huebsch,
  Petros Maniatis and Timothy Roscoe. Proceedings
  of USENIX WORLDS. December 2004.

57
???a??st?!

• http//berkeley.intel-research.net/maniatis
• http//p2.berkeley.intel-research.net/