M hnh Mng phn tnTng quan Kin trc m hnh Cc tng trong DS Cc kin trc h thng

Kin trc m hnhc imKin trc m hnh l g?Mt kin trc m hnh ca H phn tn l mi quan h cc v tr ca cc thnh phn v mi quan h gia cc thnh phn ny.c inh ngha nh l cc thnh phn ca h thng tng tc ln nhau v l cch chuyn truyn liu c bn trong mt h thng mng my tnh.

Kin trc m hnhc imMt h phn tn c hp thnh bng cc qu trnh x l thng tin trn mt h thng mng.u tin, s phn loi c thc hin da trn s phn bit ca cc kiu x l:X l trn Server X l trn ClientX l ngang hngS phn loi phn bit cc kin trc ca m hnh.

Kin trc m hnhTnh chtV d:M hnh Client ServerV tr: hai vi tr ring bit (1 server, nhiu client)Mi quan h: server cung cp cc dch v, cc client tiu th cc dch v.S lin lc: bt i xng

M hnh Peer-to-PeerV tr: c mt vai tr, ngang hng.Mi quan h: tt c u c nhim v nh nhauS lin lc: i xngclientserver

Kin trc m hnhTng SoftwareMi mt m hnh s dng m t hoc thc thi h thng da trn mt kin trc phn mm c nh ngha. Mt kit trc phn mm..xc nh t chc ca h thng phn mm (trn mt hoc nhiu my)..c th c m t bi s phi hp gia cc thnh phnCc tng (ng dng trn tt c h thng)module (cho cc h thng da trn cc thnh phn)Cc dch v (thch hp cho DS v SOA)

Kin trc m hnhTng SoftwareTi sao c cc tng?Ph v s phc tpPhn gii Cc hm, chc nngCc nhim v tru tng cc tng khc nhauM hnh kim chngTCP/IP StackKin trc ISO/OSI

Kin trc m hnhTng SoftwareCc tng trong DSPlatform- Bao gm tt c phn cng v HH Cung cp cc dch v c bn theo mc : - X l thng tin lin lc - X l hp tc v qun tr - Qun tr ti nguyn v d: - Intel x86/Windows - Intel x86/Solaris - PowerPC/Mac OS X, Intel x86/MAC OS X - Intel x86/Unix(Linux).Middleware- Cc mt n khng ng nhtCung cp s thun tin cho m hnh lp trnh To ra cc x l hoc cc i tng phn tn H tr lin lc v chia s ti nguyn - RPC / RMI - Thng bo s kin - Chia s d liuV d - CORBA / Microsoft DCOM - Java RMI / .NET Remoting - Web Services - ISO/ITU-T RM-ODP

Kin trc m hnhTng SoftwareMiddlewareMt tng thng dng pht trin cc ng dng dch vThnh phn c s h tng m kt ni vi cc thnh khc nhau trong h thng phn tn.V dSun J2EEMicrosof .NETIBM WebSphere IBM BlueCloudManjrasoft Aneka Google AppEngine

Kin trc m hnhCc kin trc h thngMiddleware l mt tng xut hin trong tt c cc m hnh kin trc hin ti.Kin trc nh tng a ra cc nhim v ca cc tng khc nhau trong h thng.S phn tn ca cc nhim v v cc chc nng ca cc thnh phn c t ti tng middleware.

Kin trc m hnhKin trc h thngM hnh Client Serverng dng cho hu ht cc H phn tn.Thc thi trn din rng.Da trn:Hai vai tr: server v clientLin lc thng tin:Bt i xngrequest (client) response (server)V dHTTP, SMTP, DNS, NNTP

Kin trc m hnhKin trc h thngM hnh Client Server

t1: request timet2: server process timet3: response timet4: roundtrip time

Kin trc h thngClient-ServerM hnh hai tng (Two-tier model)

M hnh ba tng (Three-tier server nh mt client)

M hnh a tng (Multi-tier model)Kin trc m hnh

Kin trc m hnhKin trc h thngM hnh Peer-to-PeerTt c cc x l thc hin c vai tr tng t nhau.Khng c s phn bit gia client v server.Phi hp tng tc qua li.Trnh vic tp trungPht sinh nhiu, kh qun lCung cp mt c s h tng ln(1000 host)V dP2P File sharing (OpenNAP, eMule, etc..)Distributed Hash tables

Kin trc m hnhKin trc h thngM hnh Peer-to-Peer

Kin trc m hnhKin trc h thngCc dch v c cung cp bi nhiu serverM hnh Client-Server m rngMt server tr li c th cho kt qu:Mt dy cc request-response (m hnh a tng)S phi hp x l:Phn chia thnh nhiu nodePhn hi trn nhiu nodeV d:Truy vn ni dung ca Web page bao gm:Truy vn Database.Truy vn cc ni dung tnhTruy vn cc dch v

Kin trc m hnhKin trc h thngProxy Servers & CachesCache l mt n v lu tr i tng d liu hin tiProxy servers s dng cache duy tr mt bn sao ni dung, c a ra:Kh nng gia tng ni dungGia tng thc thi cc yu cu dch vGim tt nghn trong khi truyn d liu trn din rngTruy cp ni dung, khng truy cp d liu khc (v d: firewall)

Kin trc m hnhKin trc h thngProxy Server & CacheV d:Web Browser cacheweb browser duy tr cc bn sao ca trang hin ti trn my .Phin bn ca cc trang c tr v cho cc user khi tm cc trang ging nhau.Cc tag HTML c th iu khin cc cached ca cc trang web.Web Proxy Server

Kin trc m hnhKin trc h thngProxy Servers & CachesHot ng lu tr trn Cache!

Kin trc h thngMobile Code Applet modelKin trc m hnhServerClientBrowser process space

Clients gi n servers

Dch v c cung cp bi nhiu server

Web proxy server

ng dng phn tn da trn x l ngang hng

Web applets

Thin clients and compute serversThinClientApplicationProcessNetwork computer or PCComputer servernetwork

H thng mng t pht

Bi tp 2.1M t v minh ho kin trc m hnh Client Server trn cc ng dng qua Internet.(M t trn cc v d v Web v Email).Tr li:Web: Browser l cc client ca cc DNS (Domain Name Server) v Web Server (HTTP). Cc h thng Intranet c cu hnh xen vo Proxy Server.Proxy Server thc hin nhiu mc ch khi chng xc nh cc site ging nhau ti client, chng s gim tr hon ca mng, v gim cc traffic trn mng. Khi chng xc nh cc site ging nhau ti server th chng thc thi s bo mt ti cc im kim tra (checkpoint) v gim load d liu ti server.

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BROWSERBi tp 2.1*BROWSERDNS serverDNS serverWeb serverWeb serverHTTPDNSDNSProxy serverProxy serverHTTPHTTPHTTP

Bi tp 2.1EmailSend message: User Agent (user email kt hp chng trnh) l cc client ca cc SMTP cc b v cho php tng message chuyn i n SMTP server cho vic phn phi. SMTP cc b s dng mt bng nh tuyn email xc nh ng i cho mi message v sau di chuyn message n SMTP server tip theo trn tuyn chn.Mi SMTP server nh l cc process v chuyn cc message i n n khi tn min trn a ch ca message ph hp vi tn min cc b.Cc SMTP server s c gng phn phi cc message n ni nhn bng cch sp xp trong mailbox trn a hoc trn file server.

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Bi tp 2.1*SMTPSenders IntranetNFSRecipients mailhost IntranetSending message

Bi tp 2.1Reading message: User Agent (chng trnh c mail ca user) hoc l cc client ca cc file server cc b hoc l mt client ca mt server phn phi email nh POP, IMAP server. Trong trng hp ny, User Agent c cc message trc tip t mailbox, ni c lu li trong qu trnh phn phi message.Trong trng hp khc, User agent yu cu thng tin v user trong mailbox t server POP hoc IMAP v nhn cc message t cc server ny v hin th cho cc user.POP v IMAP l cc giao thc thit k h tr cho vic truy cp mail trn din rng v c kt ni chm, v vy cc user c th truy cp cc mailbox ca mnh trong khi i du lch.*

Bi tp 2.1*Reading messageNFSprotocolNFSPOPIMAPRecipients mailhost Intranet

Bi tp 2.2Trong ng dng tho lun ca bi tp 2.1, lm cch no cc server cng tc cung cp dch v?Tr li:Web: Web server cng tc trn Proxy server ti thiu cc traffic v cc tr trn h thng mng.Mail: SMTP Server khng cn thit gi li mail trong bng nh tuyn gi cho cc a ch ch. Thay v vy, n gin l nh tuyn cc a ch ca message n cc a ch cha bit cho server khc.*

Bi tp 2.3Lm th no ng dng (trong bi tp 2.1) c s phn chia/ phn hi gia cc server.Tr li:Web: Trang Web master c gi trong file h thng ti cc server n l. Thng tin tt c trn web, v vy c phn chia gia cc web server.Mail: message c lu tr trong cc ni n. Ngha l, dch v mail ch yu da trn cc phn c phn chia, mc d mt message gi n nhiu ngi nhn nhng c phn hi vi nhiu ch n.

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Bi tp 2.4 ngh vi ng dng da trn m hnh ngang hng.Tr li:ng dng lm vic cng tc cung cp cc x l ngang hng trn mi user. ng dng cn m t trng thi tt c cc user (share whiteboard) Mt nhm ngi lm vic trn trn cc ti liu c chia s, nhng cc user khc nhau truy cp cc phn khc nhau hoc c th mt user kho mt phn ti liu v user khc khng thy c ti liu ny.

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Bi tp 2.5Lit k cc ti nguyn trn my tnh cc b c th b tn cng bi cc chng trnh download t cc site v ci ln my cc b.Tr li:Cc i tng trong file h thng gm: file, th mc m c th c/ghi/to/xo bi ngi s dng chng trnh.S lin lc trong h thng mngTruy cp my in.

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Bi tp 2.6Nhng nhn t no tc ng n vic phn hi ca ng dng c truy cp chia s d liu qun l bng server? Tr li:Khi mt client truy cp ln server, n to ra thao tc yu cu server thc thi trn mt my tnh xa. Nhng iu c th tc ng:Server b overload.C tr ca vic gi v nhn message.

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Bi tp 2.7Phn bit gia buffer v cachTr li:Buffer l mt k thut chuyn d liu t vic gi n vic nhn ca b nh cc b cho n khi qu trnh nhn c thc hin thnh cng. Cach l k thut ti u truy cp cc i tng d liu t xa bng cch lu gi mt phin bn trn b nh c b. Vic truy cp tng phn ca cc i tng t xa c chuyn i thnh vic truy cp n cc thnh phn tng ng ca phin bn cc b. Khng ging nh buffer, phin bn cc b ny c lu gi trn b nh cc b.

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Bi tp 2.8a ra cc khuyt im ca phn cng v phn mm m c th (khng th) b qua trong vic s dng h phn tn. Tr li:Khuyt im phn cng: cc x l. a, cc kt ni mng c th c s dng thc thi nhiu my tnh, vic ghi vo hai a, c hai nh tuyn phn bit trong mng.Phn mm: bug, cc h hng trong x l.

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*Course page has not yet been updated, will be by the end of the week

This is were all the important information will reside - the latest lecture nodes, assignments, marking guides, sample exams, so check it regularly!

*Course page has not yet been updated, will be by the end of the week

This is were all the important information will reside - the latest lecture nodes, assignments, marking guides, sample exams, so check it regularly!