ࡱ> DFC[@  bjbj44 .ViViPPPP@@@8x5:i.i.i.Y5[5[5[5[5[5[5$6R*9T5. .^i...5PP5h0h0h0.(PY5h0.Y5h0h004B5 ^1@/"4Y55054~94/$~945PPPP~95Hi.}.h0. .Si.i.i.55dX0How does a running process access its data?Suppose the source data is on machine A, the code to be run is on machine B, and the results are required on machine C. I see three options.Option 1: GridFTP. Copy the data files to and from the machine where the code is situated. SHAPE \* MERGEFORMAT Option 2: Distributed Access. A proxy service sends queries across the network, and caches data appropriately. SHAPE \* MERGEFORMAT Option 3: Mobile code. Move the code to the data.  SHAPE \* MERGEFORMAT SecurityOptions 1 & 2 require security on Machine B to prevent other processes, sysadmins, etc. from accessing the data.Option 3 requires security on Machine A to prevent the mobile code from accessing other data on the machine, from denying service, and from sending the data somewhere else across the wire.All options require basic security authentication, encryption, etc. Distributed File/Query AccessFile I/OMachine AMachine CMachine BMachine BMachine CMachine AFile I/OReliableFileTransferProxyCacheMachine BMachine CMachine AFile I/OReliableFileTransferMobile Code    0 1 2 4 5 6 @ R S d       μΰڨցh9*mH sH h9*h9*mH sH h/mH sH hjmH sH h Xj hoUh=jh9*Ujh{{UmHnHuh{{jh{{Uh9*jhjUmHnHuhjjhjUh/hx{he=2,-  5 6   & T gdx{gdx{gde=gde=      ! * + 1 2 $a$gdogdogdj$a$gdj      ) * + 0 1 2 7 8 9 B C D M N O X Y Z b c d z { | ʿhx{hJhoh9*homH sH homH sH hjh9*hjmH sH hjmH sH h9*mH sH h9*h9*h9*mH sH 42 8 9 C D N O Y Z c d m r { | $a$gdogdj$a$gdj,1h/ =!"#$% Dd(#D  3 @@"?Dd AD  3 @@"?Dd(#D  3 @@"?D@D NormalCJ_HaJmH nHsH tHV@V x{ Heading 3$<@&5CJOJQJ\^JaJDAD Default Paragraph FontRiR  Table Normal4 l4a (k(No ListV>@V e=Title$<@&a$5CJ KHOJQJ\^JaJ 4@4 e=Header!4 @4 e=Footer!)4?JU`ku !"#`_^]\79MLKJIf)4?JU`ku  ,-56&T !*+1289CDNOYZcdmr{|0000x00x0x0x00000x0 0 0x0x0 0x000x(000000<;00000000000000000000@0000000000000000@0@0x000&056>;0 <;0<;06;0 T 4;0D>;0>;0& h`&0   2   03___8lp@For(  &   $' N3  s"*?` O c $X99? $' n ~BCDEF:x@   } o ~BCTDEFTs6v@  A #H(L    b\ 8HVB Y # ̙"`  n \ C  "`u R PL  }8 jn }H2 R #  }4b V 0 h _ 3 "`8rL  %H i!H$'H2 a #  $Vr U # "`H! 6$ h ` 3 "`H!%HDL  =u  h = u H2 Q #  =u 4b S   L  H!y grA ZB Z S DZ ZB [ S DZD E n ] C  ]"`D H!y h ^ 3 "`d=rVr c # "`r@ Pt    d# #" . t"VB e # ̙"`  n f C "`u R*  $' ;3  s"*?` < c $X99? $'H2 = # @ $H2 > #  =u H2 ? #  4b @ 0  4b A lu .yVr B # "`H! 6$ 4b C 0 y{ D BCDEF:Tf f@  @ @  E  BCDEF:Tf f@  #" D @VB F # ̙"`  ZB G S DZ ZB H S DZD E t I S I"`u Rn J C J"`D H!yn K C K"`=8rn L C L"`8n M C M"`H!%H   $' #  s"*?`  c $X99? $'H2  # @ $ H2  #  =u  H2  #   4b  0  bb  C "`lu .yVr   # "`H! 6$ 4b  0 y{   BCDEF:Tf f@  @ @     BCDEF:Tf f@  #" D @ VB  # ̙"`   ZB  S DZ  ZB  S DZD E  n  C "`u R h   3 "`D H!yh ! 3 "`=8rh " 3 "`8h # 3 "`H!%Hh 7 3  "`   (L RD  :D ZVB 8 # ̙"`RD n 9 C  "` l B S  ?1;(#t(#tN(#tA9*urn:schemas-microsoft-com:office:smarttagsplace nw36T  !)+0279BDMOXZbdz| Dave Berry |:P}Ƴt?~E?@ABERoot Entry Fv1GData 1Table9WordDocument.SummaryInformation(3DocumentSummaryInformation8;CompObjj  FMicrosoft Word Document MSWordDocWord.Document.89q