Khóa luận Tìm hiêu hệ thống máy chủ cân bằng tải

3. Cac san pharn can bang tai 11 TM 9 CHUONG 2: MAY CHU CAN BANG T 11 2.1. Tong quan 2.2. Luan chuyen yang DNS , 11 2.3. Cum may chit yeti be can bang tii 15 2.4. Lueng WA tin ca ban trong can bang tii 19 2.5. Kiem tra tinh tang sire khoe 22 2.5.1. Clic quit trinh Idem tra ca ban 22 2.5.2. Clic cuec kiem tra tren the img dung cu the 23 2.5.3. Su php thueac via img dung 23 24 2.5.4. Kjch Bin 2.5.5. Kat Luon 24 25 2.6. Djch dja chi mpg (NAT) 25 2.6.1. NAT dfch 25 2.6.2. NAT ngwin 28 2.6.3. NAT nguqc 2.6.4. NAT nang cao (Enhanced NAT) 28 2.6.5. Djch dja chi ding (PAT) 29 2.7. Tritiai tir may chit trvt tiep (Direct Server Return - DSR) 30 CHUONG 3: THUAT TOAN CAN BANG TM 32 32 3.1. Nei dung Ichai quit 3.2. Geri thieu met se thuot man can bang tai 33 3.2.1. Thuat town Round Robin 3.2.2. Thuat toin Weighted Round Robin 33 3.2.3. Thuat toan Least Connection 34 3.2.4. Thuet town Weighted Least Connection 34 CHUONG 4: THIET ICE MANG yen Bo CAN BANG TM 35 4.1. BO can I bit, tai Whir la met be chuyen mach so yeti met be dinh tuyen 35 4.2. Cac thiet ke don gian 38 4.3. Thiet ke cho tinh sin sing cao 39 4.3.1. Active - Standby 40 42 4.3.2. Active - Active 4.3.3. Chuyen dei du phi:mg co tang thai 45 4.3.4. Da dja chi VIP 46 4.3.5. Quit trinh khei phuc b0 can bang tai 47 4.3.6. Toy chip thiet ke tinh sin sang cao 47 4.3.7. Su ciao tiep gill, ate b0 can brill tii 56 CHUONG 5: CAU HINH CAI EMT VA THU. NGHIEM 58 5.1. Gi6i thieu 58 58 5.2. Tong quan HAProxy 5.3. Cid dirt gilt phip HAProxy cho may chit Web tren CentOS 59 3 5.3.1. Thiet ice h" tilting 59 5.3.2. Hoat dOng 60 5.4. CM dat eau hinh 60 5.4.1. CM dat du hinh HAProxy 60 5.4.2. Cal dat dich vn WebServer tren Server 1 va Server 2 61 5.4.3. CM dat vit c.4u hinh KeepAlived tren Haproxy, Server 1, Server 2 62 5.5. Kiem tra & Danh gia ket quit 65 TONG !CET 70 DANH MVC TAI Lieu THAM MAO 71 4 OSI MAC ISP HTTP FTP SMTP DNS NFS URL TCP UDP IP VIP ARP RTSP STP VRRP SSL NAT PAT DSR CPU VLAN RS Open Systems Interconnection Media Access Control Internet Service Provider Hypertext Transfer Protocol File Transfer Protocol Simple Mail Transfer Protocol Domain Name System Network File System Uniform Resource Locator Transmission Control Protocol User Datagram Protocol Internet Protocol Virtual Internet Protocol Address Resolution Protocol Real Time Streaming Protocol Spanning Tree Protocol Virtual Router Redundancy Protocol Secure Sockets Layer Network Address Translation Port Address Translation Direct Server Return Central Processing Unit Virtual Local Area Network Real Server MO hinh ket not cac he thong ma Kiem soat truy cop phuang tien Nha cung cap dich vp Internet Giao that truyen tai sieu van ban Giao thin truyen tai teP tin Giao thin truyen tai thu don gian He thOng phan giii ten mien He thOng tep tin mang Dinh vi thong nhat tai nguyen Giao thirc dieu khien truyen Van Giao thin gai tin ngtroi dimg Dia chi giao thin mang Dia chi giao thirc mang ao Giao thirc phan giai dia chi Giao that trvc tuyen then gian thvc Giao thin ma rOng cay Giao thin du phong dinh tuyen ao Giao thirc lap mot ma Dich dia chi mpg Dich dia chi ding Quay troy bye tiep may chit Don vi xir 19 trung tarn Mang cvc bt) ao May chit thvc Tir vih tat "lir Day dii Giai ngltia 5 Chuang 1: GU% thieu DO Van Minh - A13439 CHUONG 1: GIOI THItU Ngay nay can bang tai khong con la met khai niem meri trong khong gian mang va may chit. Moi loai san phim thuong thgc hien cac cons viec lchac nhau trong qua trinh can ban! tai. Vi du, cac 110 djnh tuyen do the phan phoi luu lucmg truy cap th8ng qua Mien tuyen duerng de den cling met dia chi dich vi can bang tai ten cac tai nguyen mang khac nhau. Trong khi di met may chi can bang tai phan phoi luu 'wing giera cac tai nguyen may chi chi khong phai la cac tai nguyen mang. Ban dAu be can bang tai bit du veri qua With can bing tai don gian, chimg nhanh chOng duqc phat trien de thgc hien met bat cac chic nang: can . bAng tai, Icy thu#t phan ph& luu Itrqngt chuyen mash lugng thong minh. Be can bang tai cling c6 the thuc hien cac cuOc kiem tra sic khoe met cach tinh vi ten cac may chii, cac ing dung, va ca nOi dung de cai thien firth sin sang va Ich# Wing quan IS, . Bei vi b0 can bang tai dugc trien khai nhu met may chit tiep nh#n you cau cult met nhim cac may chii, chting cling bao ve cac may chi ti ngueri ding dec hai, va tang cuang kha nang an ninh bao mat. Dtra‘ tren th8ng tin trong cac g6i tin IP hoac nei dung trong cac you cau ing dung, be can bang tai Qua ra cac quyet dinh thong minh de dinh huang cac luu Wang thich hqp den ding trung tam de lieu, may chi, tiring lira, b0 nher cache, hoac img dung. De tai nay se tap trung nghien ciru tong quan ve may chi can bing tai, cach thic hot dOng cia be can bang tai trong Wan be he thong mang, tir d6 img dung tren dux to trien Mud be, can bang tai tren toan b0 he thOng met cach hieu qua va (tat dugc hieu suit tot nhat. De tai se dtra ra met m8 hinh cu the, ap dung thu#t toan di chqn Itra de dtra ra cach nhin re hon ve yin de thing to dang Wang teri. 1.1. Sr can fillet cia can bing tai CO hai xu huortg clan den sy can thiet cia can bang di lit may chi va mang. Veri st ir vtrgt trei dm Internet va Intranet, ket not mang giita may chi va may tinh ca nhan cia !than vien, khach hang hoac nha cung img di trer titbit 'diem vu quan trong. se khong the chap flan dirge khi mang bi sap hay the hien kha nang lam viec yeu kern, khi d6 no hau nhu se tri tre moi host &Ong kinh doanh trong nen kinh to dua nhieu vkInternet. MOt vi du nhu xay dtmg met website thuong mai Bien tir, c6 rat nhieu be phan can dugc xem xet nhu la: b0 djnh tuyen, be chuyen mach, Wang lia , be the dem, may chi web, may chit ca ser cla lieu. Hon Ilea viec gia tang nhanh cia ck may chi cho hang lost cac img dung di kW& cho trung tan.' dit lieu day ip cac cum may chi. Su r6i ram va thach thirc trong khit nang nier rOng, kha nang quart ly va khit tiling sin sang cia cia cac nhim may chi la met nhin to dimg ding sau den hei can ci met su thay doi thong minh. Met thir ma .n8 phai chic chin ve kha nang mer reng va firth sin sang cao cho mgi thanh phan, bat dau tir be dirt tuyen ket not voi Internet, cho to; tat ca cac con dutng teri may chi de lieu ben trong. Tir di thiet bi can bang tai St hien nhu la met vu khi mang me de xi ly nheng van de tren. 6 Chuang 1: Gi6i thieu DS Van Thinh — A13439 1.1.1. Mai trwang may chu Sp phat trien manh me cea may chti trong cac doanh nghiep ngiy nay va viec cung cap dich vu Internet (ISP) xuat phat tir hai do chink. Tar& het, co rat nhieu cac Img dung hay dich vu can den trong k9 nguyen dm Internet nhu Web, FTP, DNS, NFS, Email, database, ... Tha hai, rat nhieu img dung deli hai can co nhieu may chu cho moi ling dung bed vi met may chit khong the cung cap MI sirc mph hay !chit nang de dux wen cac you cdu ctia Ung dung do. Nei chuyen v6i bat dr met ngueri nao lam viec von hanh trong tam dii lieu, he) se cho ban biet can bao nhieu thin gian de xix 19 nhang van de ve kha nang quan 19, kha nang ma rOng va tinh skin sang dm nhieu loci img dung tren cac may chti. Vi du, neu met tiring dung email lchting the xi: 19 st ir tang len ye nguiri dung, met may clui mail se duqc bo xung trien khai them. Ngutri vim ly cling phai nghi cach de phan tai gitta hai may cliff nay. Neu met may chi' gap van de, ngueri quin trj ngay luc de phai chay ung dung ten met may chif khic trong khi may chit Tat van de duqc sin chila. Khi no da dugc sin xong, no phai dua ter lai de phuc vu. Tat ca nhftng nhiem vu do inh huerng tai tinh skin sang va hieu qua dm CEng dung d6 deli v6i ngtreri &mg. Thech thzec ve kha ?long ma rang: van de ve quy me ding suet may tinh khong con la mai. Tn.rerc day, met may chti duqc clanh de chay met img dung. Neu may chii de khong hoan thanh nhiem vu, thay vac) de met may chit mph han se dugc mu, meri. Stic manh cua cum may chi' tang len khi tong bo ph#n khic nhau trong town he thong tra len manh me han. Vi du, chung ta da thay toc do elm be xti 19 duce Ling gap deli cu sau mai 18 thang - met hien Wong ngly nay dirge biet tai nhu la luOt clia Moore, dOt theo ten dui Gordon Moore dm top doan Intel. Nhtmg nhu eau sir dung may tinh tang thorn chi con nhanh han. Gong nghe cum (clustering) do de da dugc phat mink 1.1.2. Mai truirng mgng Thiet bi chuyen mach truyen thong va be dint' tuyen host dOng tren dja chi IP hoac dia chi MAC de xac djnh diem den curt gel tin, tuy nhi 'en, chimg kh8ng the xi: 19 cac nhu cern dm cac cum may chti phtirc hop hien du. Vi du, cac be dinh tuyen hoac b0 chuyen mach khong the thong minh khi girl ltru luong truy cop den met may chit cu the hoOc be nher cache. Neu met may chil dang bj hang, thiet b1 chuyen mach truyen thong yin tiep tuc gfri Iuu Itrqng truy cop vim melt may chi' da chet, de hieu dugc chirc nang ctia HU& N chuyen mach vi thiet 111 (firth tuyen truyen thong thi dau tien chung ta phai kiem tra m8 hinh mang OSI. 7 Chuang 1: Gieri thi0 DO Van Minh — A13439 Layer 7 Layer 6 Layer S Layer 4 Lam 3 Layer 2 Layer Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link Layer Physical Layer Hinh 1.1: so tla ma hinh MO hinh OSI la mOt tieu chitin ma de xac djnh Mm the nao ma cac thiet bj hoc may tinh khac nhau co the giao tiep dugc yeti nhau. N6 bao gtim 7 tang, Ur tang vat 1S7 den tang (rug dung tuang Mfg vai cac tang la cac giao thfrc ph6 bien. BO chuyen mach va b0 djnh tuyen lam viec a lap 2 va 16.p 3, se xac dinh mOt gei tin phai duqc xir IS , nhu the nao va not ma gei tin phai &gm girl dua tren !hong tin trong phan header. Tuy nhien chang to se khong di qua sou vao m8 hinh trong de tai nay. IITIR F17. SNMP. Telnet. DNS TCP. UDP IP 1.2. Can bing dinh nglifit va frng dying VOi su ra dai dm Internet, mang hien nay hien chiEm san khau trung tam. IChi ma Internet ket not the gith vOi mang b0 ne se ter thank xucmg song hour dOng cho cac doanh nghiep, lac nay co se hu tang cling nghe thong tin ce the duce coi nhu la hat loai thiet bj: may firth ce chat Ming nhu may khich/ hoc may clth, thiet bj chuyen mach/ b0 djnh tuyen kEt not cac may tinh. BO can bang tai la eau n6i gifts cac may cho vi mang. dirge the hien ton§ hinh. Mitt mitt, bel can bing tai hieu nhieu giao thirc lop cao hon, do de ne c6 the giao tiep vai cac may chil thong minh. Mat khac, bij can bang tai hieu cac giao thine mang, do d6 n6 co the tich hap yen cac mang khic mOt each hieu qua. Hinh 1.2: cam may cho vari ba can bang tai 8 Chuong 1: Giai thieu D6 Van Thinh - A13439 Can bang tai dirge img dung trong rat nhieu twang hap nhu • Can bang tai may chit (Server load balancing) • Can bang tai may chit town cau (Global server load balancing) • Can bang tai tubing lira (Firewall load balacing) • Chuyen mach be nha cache (Transparent cache switching) • Can bang tai tren &rang truyen Internet (Load Balancing with multi wan and failover) • ... Can bang tai may chti xir ljr v&i viec phan chia tai theo cac may chit (multiple servers), quy m6 hea trong kha nang litm viec cita timg may chit va dam bao kha nang chit' dung khi met may chit nao de khong host clang. Can bang may chti tat town cau xir l5r viec htrang ngu&i dung truy cap tai nhung diem khac nhau not dat trung tam du lieu, bao grim cac cum may chit c6 kha Ong cung 1mg cho ngtrai dung thai gian phan hei nhanh nhat c6 the va chili dung khi met trung da lieu mat kha nang lam viec. Can bang tai twang hia phan phei tai qua cac twang lira (multiple firewalls), quy mo hoa trong kha nang cita tong tubing lira vi dam bio kha nang chili dung khi met tubng lira mat kha nang lam viec hoan town. Chuyen mach 60 nha cache la Wang ltru lugng fly cop den cac cache de tang tee theri gian dip thig cho khich hang hoac cai thien hieu sat cim cac may chit Web bang viec tai cac net dung tinh dua den cac cache. Can bang tat tren (twang truAn Internet la giii phip &up tang bang th8ng co sin do ca kha nang sir dung deng thtri nhieu lien kat. NO cung cap can bang tai cho cac nha cung cap dich vu khic nhau va cho cac ket not wan bang viec tOng slicip va tao dieu kien gitip tang kha nang 161 cho mpg dien renf thong qua chuyen doi du phOng. Do d6. cac ket not Internet duqc bao dim an Wan, ket not On dinh vol ben ngoii va dam bio chat 'mpg dang tin city trong truyen din. 1.3. Cic san phfim can bAng tai Cac san phim can bang tai co sin duch nhieu hinh thirc khac nhau. Chung co the duck phan chia thanh ba loai: sin pham phan mem, thiet bj, vi thiet bi chuyen mach. Phan mieu to ciia 3 loai theo sau dual day: • Phan main can bang tdi la phan mem chat' tren ck may chit to can bang tai, Slang phan mem nay thuc hien cac thuat toin di dieu phial quit trinh phfin phoi tai. 9 Chuang 1: Gith thieu DO Van Thinh - A13439 • That 14 can bAng tai IA dm phAm hOp den bao gem phAn ming NM phan mem an duet de thvc hien nhiem vu. HOP c6 the don gian nhu met may tinh hoac met may chi, dugc dang gal yeti met s6 hg dieu hint' va phan mem dac bigt hoac met hOp dee quyen vOi phan cling vA phan mem tay chink. • Thiit bf chuyin much ma rOng cac chile nang cim mot lap truyen thong (16p 2/3) chuyen dei thAnh cac 16p cao hon bang cach sir dung met so phan cling va phan mem. 10 Chuang 2: May chic can bang tai DO Van Thjnh - A13439 CHIANG 2: MAY CHU CAN BANG TAI 2.1. Ding quan Ngay nay may chit can bang tai khong con la mOt khai niern mai trong the gieri may chit. Ck Gong nghe dun may chit da duqc phat minh d'e c6 the thus hien cac uhiem vu tinh toan, nhung lei chi c6duqc thitnh ding trong mOt s8 it cac th8ng dOc quyen. Tuy nhien can bang tai da xuat hien nhu mOt giii phitp mph me clanh cho cac img dung chinh cung nhtr giai quyet cac van de cho timg khu Arc , ne bao gom lcha ndng mer rOng cac nham may chit, tinh san sang, !chit Wins bao mat va khi ndng %Wit ly, not each khk can bang tai la mOt phucmg pluip phan phoi khOi luqng tai tren nhieu may tinh hoac mOt cum may tinh de c6 the sir dung t6i uu cac ngurin lye, tOi da hOa thong lucmg, giam theri gian dap ting va tranh firth trong qua tai tren may chit. Cac lqi ich khi sir dung phucmg phip can bang tai: Tang khd ndng ddp itng nto rPng cai thin clang ke kha ndng ma rOng vita mOt ting dung hoac nhem cac may chit bang each phan ph6i tai th8ng qua cac may chit dam bio firth firth host va ma rung cho he th8ng. Tang 60 tin cPy link sin sing gitip tang grill sin sang cao (High Availability) cho he thing, bed vi n6 co the dinh huemg cac Itru luqng truy cop den cac may chit thay the neu mOt may chit hoc Ung dung kh8ng the dap img dirge d6ng thin dim bao cho ngtrai dung khong bj gian down dich vu khi xay ra l6i str c6 loi tat mOt diem cung cap djch vu. Cdi thin khd ndng quits iy theo nhieu each thirc thong qua viec cho phop nhimg ngtrai quan trj mang va may chit chuyen cac img dung tir mot may chit nay den mOt may chit khac hoac c6 the them nhieu may chit de chay the ang dung nhanh nhat Tang link bdo mPt cho he lung, thong thuang khi ngueri dung giri you au djch vu den hg thong, zyeu au do se duce xir tren boa can bang sau de phin can bang tai mai chuyen tiep cac you eau cho cac may chit ben trong. Qua trinh tra lai cho khach hang ding thong qua thinh phin can bang tai, vi voy ma ngtrai dung khong the Wit duqc chinh xac cac may chit ben trong ding nhtr phuang ?hap phan tai dugc sit dung. Bang each nay c6 the nglin chan ngu&i dimg giao tiep (rut tiep veri cac may chit, an cac thong tin va cau trite mpg nOi b0, ngan ngua cac cuOc tan cling tren mang hoc cac djch vu khong lien quan dang hoot &Ong tren cac ding khk. 2.2. Luan chuyen Wong DNS 11 Chuang 2: May chit can bang tai DO Van Thjnh - A13439 De can bang tit may chit, he th8ng an phai phan. phiii ck yeu a it u den nhieu may chit khac nhau ben trong ctun may cho, vii mix dich toi uu h6a hieu suit he thong. Dieu nay se mang den cho mang hieu suit cao han, khi nang ma reng, tranh rat vao tinh trong tong thieu tit nguyen mang trong met doanh nghiep hay met img dung nao do. Tinh sin sang cao co the dtrqc hieu 11 firth trong du thira. Neu met may chit Ichong the plan 19 met you cau thi .cic may chit khac ton* cum may chti do co quart 19 di:cc ne khong? Trong met th6ng c6 !chi nitng ‘ cung cap cao, net met may chit bi thi may chd khac se tiep quin ngay dezir 19 yeu cau. Kha nang ma reng dm met *rig dung ce the 118 trq duqc so lucmg ngueri ngly met tang. Neu no can 10ms de met img dung co the dip Uzi cho met yeu cau thi khoang th6i gian se la bao lau de n6 dap tra den 10.000 yeu cau cling met Mc? Kha nang ma reng v8 hurt se cho phdp no dap tra ck you cau nay chi trong khoing 10ms. Kha nang ma reng la don vi do cho met lost cac he' so nhu so Itrqng ngubi dimg dung thtri ma met cum may chtl c6 the h43 trq va thbi gian no can de xir 19 met you au. Frau het chung to co le deu da biet rang, DNS ban di\ h6a ten host thanh ck ilia chi IP. Ngubi dung nhip wwwkoircom vio hitp tha chi cite trinh &wet web Web Bravest Cho UN met Oa chi IP cOa www.kok.com Database DNS Sena Dia chi P cua www.koiccom 222 255.31 160 Database web Dro'neer DNS Saver GET 222 255 31.160 Web Stores web &o'er Hinh 2.1 qua trinh chuyin deli host thanh Ma chi 12 222.255.31.160 www.kok.com Luan chuyon Ana DNS 222.255.31.161 Chuang 2: May chi' can bang tai Da Van Thjnh — A13439 Khi nhap mot URL vao trong trinh duy (vi du ram www.kok.com ) thi trinh duyet se giri mot yeu cau den DNS yeu cau no tra ve dja chi IP dm site. Day dugc goi 11 viec tra ciru DNS. Sau khi trinh duyet Web co dugc dja chi IP cho site thi ne se lien he yeti site bang dja chi IP, vi hien thi trang vim yeu cau. May cha DNS thubng co mot dja chi IP dugc ban do boa yeti mot ten site nlo d6. Trong vi du thi site la www.kok.com ban do hos thanh dja chi IP la 222.255.31.160. De can bin tai bang DNS, may chii DNS phai duy trinh mot s6 dja chi IP khac nhau cho cling mot ten site. INThieu dja chi IP the hien nhieu may trong mot emu may chia, tat ca trong so chung deu dugc ban do hem den mot ten site logic. Trong vi du, www.kok.com c6 the dugc cau hinh tren ba may cha trong mot cum may cha yen cac dja chi IP dual day: 222.255.31.160 222.255.31.161 222.255.31.162 Trong trutmg hop nay, may chi) DNS dugc ban do hea nhu sau: www.kok.com 222.255.31.160 www.kok.com 222.255.31.161 www.kok.com 222.255.31.162 auster 222.255.31.162 Hinh 2.2: Luein chuyin yang DNS Khi yeu au diu tien den dugc may chi' DNS, no se tra V& dja chi IP 222.255.31.160, may dau tien. Khi c6 yeu cau thir hai, n6 se tra ve dja chi IP this hai: 222.255.31.161. Tiip tic nhu vay, veri yeu eau thli tu, dja chi IP diu tien lai dugc lap lai. 13 Chuang 2: May chit can bang tai 06 Van Thjnh — A13439 Bang each sir dung luan chuyen wing DNS nhu a tren, tat ca cac you cau dot yeti mot site nao do deu &me phan phot i deu den tat ca cac may trong cum may chit (cluster server). Chinh vi vay, vai phuong phap can bang tai nay, tat ca the may chit trong cum may chit deu duqc sir clung. diim chink ctia phuong plulp - Khong dit vi a ding thiet lip: Cac quan tri vien hg thiing chi can tao mot se thay dot trong may chit DNS de hi!, trq duqc viec luan chuyen yang, va nhieu may chit DNS da co stir ho trq nay. N6 thong you cau den stir thay del ma cita (mg dung Web; trong that te, cac (mg dung Web khong he biet ye co the can bang tai ma no hi that hien. - Don gian: Phuong phap nay khong yeu cau den the chuyen gia ye mpg trong vik thiet lap hoac gia r6i he thong trong twang hqp co van de nao de xay ra. Nhuvc dam min phweng phdp Co hat nhuqc diem chinh cart phuong phap dtra tren phin mem nay la no thong cung cap sr ht!) trq m8i quan hg thai gian that gifta the may chit veri nhau va khong ht) trq Icha nang co sin cao. - Khong ht3 trq m6i quan hc. thai gian that gitka cac may chit. MOi quan hg thin gian that gift cac may chit la kith nang cita he thong trong viec quart 1Sr cac yeu cau cita nguiri dung, may chit nay hok bat kt may chit nao, phu thuOc vio th6ng tin phial .' duqc duy tri tren may chit hoac tai mire co sit, mac co sit dft - Khong co duqc kha nang ht!) trq mei quan he gift cac may chit, phuang phap loan chuyen yang DNS dtra vio mot trong ba phuong phap de duqc dtra ra de duy tri sit kiem soat cac phial hoc sit nhan clang nguoi clang 461 yea cac you cau dang den ten HTTP. • Cac cookie • Cac trutmg An • viEt URL Khi mot nguai dung dux hien mot yeu cau dAu tien, may chit Web se tra mot the bang van bin duy nhit de phan biet nguai dang do. Cac you cau tiep theo co the nay de sir dung cookie, viet 10 URL hoc cac truang An, cho phdp may chit xuat hien de duy tri mot phien glen may khich vi may chit. Khi nguai dimg duet lop mot phien veri mot may chit, thi tat ca cac yeu cau den sau thuang deu di den cling mot may chit. Van de a day la trinh duyet luu dia chi IP cart may chit do. Khi Cache het han, trinh duyet se that hien mot yeu cau khac din voi may chit DNS de co duqc dia chi IP co lien ket yen ten mien. Neu may chit DNS tra ye mot dia chi IP khac, mot may chit khac trong cum may chit, thi cac th8ng tin ye phien se bi mat. 14 Chuang 2: May chit can bang tai DO Van Thjnh — A13439 - IChong ha trq cho kha nang c6 san cao. Xem xet met gun may chit co n may. Neu met may chit nao d6 gap van de ye stir co (vi dy la may chit thir n) thi cu yeu au thin n den may chit DNS deu huemg yeu au din may chit hong nay. MOt be djnh tuyen thong minh co the giai guy& duqc van de nay bang cach kiem tra cac may chit 6 cac khoang uteri gian nao do, phat hien ra cac may chti bj h6ng vi ger b6 chimg ra Ichoi danh sach, chinh vi vAy se khong co yeu cAu nao duqc gfri den chting nits. Tuy 4y, van de a day van ton tsi neu may chili van c6 nhung Cling dung Web dang chay tren may chit eta bj hang. Thay dot cum may chit se mat nhieu thiri pian de truyen bi den toan be plan con lai cita Internet. MOt IY do 6 day la trong nhieu to chirc tern — cac ISP, cac cong ty, hay dui ly — hru cac you au DNS dm hp de giam Itru luqng mang va thai gian you au. Khi ngtreri dimg ben trong cac t6 chirc nhu v0y thuc hien met yeu au thi hg thong se duqc kiem tra danh sach cac ten DNS cita Cache da duqc ban do h6a (Ha chi IP. Neu hg th8ng phat hign thiy met muc nao thi no se tra dja chi IP ve cho ngueri dimg. Neu no kh8ng phat hien thay muc nao trong cache nei be thi ISP se giri yeu cau DNS nay den may chit DNS vi km sr dap tra. Khi met muc da duqc luu het hen, ISP se nang cap ca so da ligu n6i be dm no bang ach lien he voi cac may chit DNS khk. Khi danh sach cac may chit thay dai, no c6 the can den met Ichoang uteri gian ngin cho cac muc da duqc Iuu tren mang cita ac to chat khic het han va tim kiem danh sach cac may chti da duce cop nh#t. Trong su6't chu trinh nay, may khach van co the thuc hien hanh deng " Hit " may chit 1)1 hang, neu ISP cita may khach do van c6 met mix tr6 den no. Trong twang hcq? nhu 4y, met so ngueri dimg cita ISP d6 khong the truy c#p tir nhemg lin truy c$p ban dliu, tit* tri hien tai cum may chit van con cac may chit du thira van dang host deng. Met van de con Ion han xuat hien khi ger be met may chit so veri viec ba sung. Khi bat di met may chit, ngueri dung co the dang thuc hien " Hit " met may chit khong ton tsi. Con khi them met may chit thi may chit de van chtra duqc sir dung cho toi khi dja chi IP cita n6 den duqc tat ca cac may chit DNS. Mac clit phuong phip nay c6 the can bang ducc met s6 lircong ngutri dimg tren mai may chit, nhung n6 kh8ng hoin toan can bang tai may chit. Met so ngued dimg co the you au mirc tai cao han trong suot met phien cita hp so veri nhang ngtrai dung khic a tren may chit khic, vi phtrcmg phap nay khong the bao dam chang lai duqc sit bat cong bing do. 2.3. Cym may chit voti bt, can bing tai Met vii nha quin tri may chit se trien khai nhieu may chit de dam bao muc dich tang tinh san sang vi kha nang mer ding. Neu met may chit nao do gap phiti van de kh8ng the dap *rig duqc nhu au, ngay 10p tire met may chti khic cet the duqc mua trong khi may chit gap van de se trong qui trinh sira chaa. Tnrerc khi cac sin phan can pang tai duce phat minh thi DNS thutrng duqc sir dung de phew ph8i tai thong qua nhieu may chit. Vi du, 15 Rtal %PMI'S Chuang 2: May chit can bang tai DO Van Thjnh — A13439 DNS quan IS, dja chi www.kok.com c6 the dirge cau hinh yeti hat hoac nhieu dja chi IP cho site www.kok.com DNS sau d6 c6 the cung cap mOt trong cac dia chi IP da ductc cau hinh bang cich lam chuyen yang cho mot truy van DNS. Day mei chi la sv hob thanh the,' scr oh qua trinh can bang tai, cach tiep cjn nay can bj giOi hart trong nhieu van de khac. DNS khong the biet duqc kha nang tai va firth trang cim mOt may chit. N6 co the cung cap dia chi IP cim mOt may chit ngay ca khi may chit nay dang gap van de. Bo can bang tit s xuat hien va duqc trial khai tnretc nhOm may chit, tat ca cac may chit nay hoac trvc tiep ket not yeti can bang tai hoac ket not thong qua b0 chuyen mach, b0 can bang tai chay dvc theo cvm cac may chit xuAt hien nhu mOt may chit a° di den cac may khach. Cling nhu la may chit that may chit ?to phii co dia chi IP cho cac may may khach truy cap vao n6, day &gm goi la dia chi IP ao (Virtual IP - VIP ). Dia chi IP ao dirge cau hinh tren b0 can bang tai va dai dien cho toan b0 nh6m may chit ben trong. Memo Sinn 1111n 102.121.10.1 ars 1.00d Man 1 16.2 11110102 11kb WM ItS3: 1010103 SMIP Hinh 2.3: nhom may chit yogi ba can bang tai De truy cap (mg dvng tren cac may chit, dja chi may may khach phai you cau den VIP. Trong truing hqp cita vi dv trang web www.kok.com , DNS phiti sauce cau hinh tra lei VIP gi6ng nhu dja chi IP www.kok.com . Dieu nay cho tat ca cac trinh duyet cita may khach girl yeu cau teri cac VIP thay vi mOt may chit thvc. BO can bang tai nhan dirqc you cau beri vi n6 so hau VIP va phan phoi chimg qua cac may chit thvc sit c6 an. Khd hang mi ring: Ben vi can bang tai phan phoi cac you au dm may khach thong qua tat ca cac may chit thvc sari c6 vi the cong suet zit ly dm may chit Ito cling lem hen Ming suet cita mOt may chit. BO can bang tai sir ding mOt thuat toan phan phoi tai de phan phoi den dm yeu cau cua timg may Ichich. Neu thuat toan toi tru, kha nang nang cita may chit ao se bang ming suit Ping hqp dm tat ca cac may chit thvc. Nhung truing hqp nay la rat hiem do mOt so yeu t8 bao gom ca hieu qua phan ph8i tai. Tuy nhien ngay ca khi ding 16 Chuang 2: May chit can bang tai DO Van Thjnh - A13439 suit dm may chit ao dat khoang 80-90% ding suit tong hop cita tat ca cac may chit Sic thi dieu nay cling dg cung cap kha tiling ma tong that tuyet vet Tann sin sang: BO can bang tai lien tic theo dei tinh trong ctia cac may ,cha ,thoc va cac ling don chay tren chimg. Neu mot may chit thoc hoacimg ding gap van d'e kh8ng dap Ong ducifc yeu cau, b0 ram bang tai tranh gut bat kY yeu cau cita may khach den may chit de. Mac di" bat cir mot so ket not hok cac you cau dang &roc xir 1S, khi mot may chit dang gap yin de thi b0 can bang tai van se dj enh Wong tat ca cac yeu cau den mot trong so cac may chit c6 tinh tang kit& manh. Neu khong co bo can bang tai, ngulyi ta phai doa tren mot c8ng co giam sat mang de kiem tra tinh tang cua mot may chit hoac ling ding, va chuyen huOng may khach den mot may chi) thoc khac. BOA vi 130 can bang tai thoc hien ding vi'ec nay mot cac nhanh chong , nen thoi gian chat ducic giam thieu ding ke. mot khi may cha bj 16i dtroc sua chea, b0 can bang tai se phat hien so thay dOi vi bat diu chuyen tiep you cau den may chit. Khd ming van /57: Neu phan ding cua mot may chit can duce ang cap, hok hg diau hanh, hoac ling ding phan mem ctia no phiti nang cap len mot phiety ban men, may chti serhai dimg hoot dOng. Mac do viec nano cap nay co the duqc sap xep vilo gib cao diem de gram thieu tic (tong cua that gian chet vi se co mot vii doanh nghiep kh8ng ce co du kha nang dank cho khoang thai gian chet nay. MOt s6 doanh nghiep thin w con khong the tim thay bat ky thai gian nap ngoai gib cao diem, dac biet la neu may cha dugc truy cop bed nguOi dung tren town the gieri trong nhftng mui gib khac nhau. Bang cach trien khai b0 can bang tai, chting ta co the ngimg may chit can bao tri ma kh8ng phai chill bit cir thai gian chat nao. Ck can bang tai se thoc hien mot cach khdo leo viec tat may chit, theo d6 can bing tai se dung dua ra yeu cau meri voi may chit d6 va cho dqi cho den khi bit Ick mot ket not hien c6 cham dirt. MOt khi tat ca cac ket not hien c6 duce dang 10, may chit co. the an town ngimg lam viec de bao tri. Vic nay dim bito may khkh kh8ng he hay Wet va bo can bang tai se tiep toe phoc vi cac yeu cau gin den den dja chi IP ao bang cach phan phoi chimg qua den cac may chit thoc con lit. BO can bang tai cling tang kha nang quan 15, bang each ttich (mg ding tit may chit. Vi do, chimg ta c6 tat ca !man may chit thoc sari sang lam viec, va cluing ta can chay hai ling citing: Web (HTTP), va FTP. Chimg ta chon chay FTP tren hai may chit va chay Web server tren tam may chit can Iii Uri vi nhu cau can Web server la nhieu han. Khong co b0 can bang tai, chimg ta se sir don DNS de thoc hien luau chuyen yang glib hai dja chi IP may chit ch...n may chit thuc. Cac may khkh se khong nhan ra bit Ic9 sir khk biet nao va trinh duyet web tiep tuc gut cac yeu clw den con; 80 dm VIP. BO can bing tit djch s6 cong trong tat ca cac yeu caur den vi chuyin tiep den cong 4000 tren may chit thuc. Bay gib, khong met ai co thE tan cong cac may chit truc tiep bang cach thong qua viec 1, 11m luqng nguy hie'm den cong 80, bed vi no da duqc den. Mac divoy, tin tac co the co ging de tim niang cong dang ma, diEu nay chi tao ra Wit chat kh6 khan hon. Gan (Ha chi IP private den cac may chit thtrc hoc thtrc hien kiem soat danh sach cac truy cap de tit chei tat ca cac ltru luqng truy cap den dia chi IP cita .may chit thuc, diEu nay se buetc tat ca nortri ding phai thong qua bo' can bang tai de co the truy cap vao cac may chit dive. BO can bang tai sau d6 co the ethqc thi chinh sach truy cap nhat dinh vi cling co the bao ve may chit ch8ng lai mgt so loci hinh tan cling. 29 Chuang 2: May chit can bang tai DO Van Thjnh — A13439 Dich dja chi cong giiup cal thin kha nang me rung bang cach cho phep chay nhieu img dung tuong tfr ten nhieu cong. Ben vi yeti cach mOt so img dung duqc thiet ke chimg ta co the ma rang hiOu suit ang dung bang each chay nhieu ban sao elm no. Thy thuijc vao img dung, chay nhieu ban sao co the sir dung nhieu CPU hieu qua han. De dua ra mOt vi du, chting ta c6 the chay Microsoft IIS (Internet Information Server — Microsoft -- phan mem may chit Web) tren nhieu cong. Chin ta co the chay HS troll cong 80, 81, 82, va 83 tren min may chit thurc va can rang buoc cong 80 tren VIP cho mot cong chay HS. BO can bang tai se phan ph6i luu Krung truy cap khong chi ten khip the may chit thue, ma can ca cac cong tren mot may chit thirc. Dich dja chi ding cling co the cat thin kha nang quan ly trong cac tinh huang nhat dinh. Vi du, khi chitng ta luu tit cac trang web tren mOt tap the may chit that, chimg ta co the sir dung dja chi VIP de dai din cho tat ca cac website. BO can bang tai nhan dirge tat a cac yeu eau web ten cong 80 cho cong mgt dja chi VIP. Chimg ta co the chay cac ang cbmg may chit Web ten mOt cong khic cho mot ten mien website. Chit han, cac may chit Web http•//www.abc.com chay tren cong 80, va chay tren cong 81. BO can bang co the duqc eau hinh giri cac luu lugng truy cap vao cong thich hqp, thy thuk vao ten mien trong URL cita mot yeu cau HTTP. 2.7. Trir lai tir may cho film tiep (Direct Server Return - DSR) DSR lien quan den, viOe chophdp may chit Ulm tiep tra km lugng tray cop ma khong th8ng qua b0 can bang tai. Bang cach ;thong th8ng qua b0 can bang tai, thong ta co the co dirge hieu suet tot han neu b0 can bang tai la nth c8 ehai, bai vi bay gia ,b0 can bang tai chi phai xir19 cac luu lugrig you eau, cat giam doge so lugng the goi tin can phai xir 19. Qua trinh thiet lap de that hiOn DSR, b0 can bang tai se khong chuyen dia chi IP dich thanh IP cita may chit ma van gift nguyen la ilia chi VIP (IP public). BO can bang tai chi dOi dia chi MAC dich thinh dia chi MAC cita may chit de gai tin co the den dugc may chit. Van de con 13i la lam sao de khi may chit nhan gal tin you eau tir 116 dinh tuyen chuyen den se khong tir ch6i, vi dja chi IP dich kh8ng phai la IP cita may chit, ma la dia chi VIP. MOt each dim gian, ta cau hinh de dia chi VIP la dja chi cita loopback interface tren mot may chit. BO dinh tuyen dung cach nay vi lqi dung nhUng tinh chat thti vi sau day cita loopback interface: • Co the gin bat Ict dia chi IP nao, khong bit buOc phai bit dAu bang 127.x.x.x • Vi loopback interface khong phai la mOt thiet bi that, no kh8ng co dia chi MAC, nen hg thong se khong tra lai cho cac yeu cau ARP. Do 66 se khong co hg thiing ben ngoiti nit° ilia dirge dja chi IP cita loopback interface. Tuy nhien, hg thong van nhan you cau den IP cita loopback interface va tra leti tutu la cac interface Ichic. Nhu vay, bang mOt chit thin thuat vii cac dja chi, may chit thfrc khong an dja chi IP public van co the nhan you cau va tra Itri trip tiep cho may khach. 30 Chuang 2: May ch6 can bang tai DO Van Thjnh — A13439 Hinh 2.10 the hien luting gal tin khi sir dung DSR. Dim tien, b0 can bing . titi gift nguyen dja chi IP dich van nhu la dja chi VIP trong gei tin yeu ceu, nhtmg thay doi dia chi MAC dich cua may chit da duqc chqn Itra. BO chuyen mach lap 2 gifta bo can bang tai va may chit chuyen ti .ep g6i tin den dung may chi' dua tren dia chi MAC dich. May chit thuc se chap nhan gai tin bai vi dia chi IP dich caa goi tin vi dja chi VIP da duqc djnh nghia nhu la dia chi IP loopback tren may chit. Khi may chit tra 16i, dia chi VIP bay gibt trot thkh dja chi IP nguon, va dja chi IP dm may khkh tra thank Elia , chi IP dich. ,Goi tin duqc chuyen tiep thong qua b0 chuyen mach lap 2 den b0 djnh tuyen, vi sau do den may khach ma Ichong can phai sir dung NAT. Chen • HS 1.1 100 41.14E65. MAC -MI 141 1411 48.3 MAC-M2 Same 111' Dna 111 Sown MAC One MAC 1 Mill 180 141 148115.3 MI MZ 2 Ull I 1.180 141 I 411 116.3 MI M2 3 188 Lo 110 141 140116.3 M2 MI 4 141 1046 3 188 I 1 100 9114 MI 5 141 IWO 3 18111.1 108 544 MI 10 0.10.10 MAC-M3 10.10 1• 28 MAC Hinh 2.10: Luting goi tin khi s& dung DSR DSR rat hftu ich cho nhftng img dung ton bang thong nhu FTP, phtrcmg tien truy'en thong, Ida ma kich thuac cac ged tin tra led la rat Ian so yen kich thuac cac gai tin you cau. thuat nay cung duqc img dung cho nhftng &iao thirc dei h6i phirc tap khi thuc hien NAT hay khong duqc bp djnh tuyen h8 trq. Chang han nhftng giao thirc phucmg , tien truyen thong nhu trong phan NAT nang cao (Enhanced NAT) da de cpp, thi ta co the dung DSR thay vi NAT. Chang ta ding nen can nhAc sa dung DSR khi trien khai tren mo hinh mang, khi ma hru luting tra 1oi tir may chit kh6ng dam Ho IA se di dung dich. 31 Chuang 3: Thu* toan can bing tai DO Van Thinh - A13439 CHIYONG 3: THWiT TOAN CAN BANG TAI 3.1. Nie dung kluii quit Be can bang tai sir dung thuot toan I9c phan tan hoan toan de anh xa cac may khach den cac may chit trong nh6m. Thuat toan nay cho phip cac may chit trong nh6m din ra cac quyet djnh can bang it met each dec lap va nhanh chong cho ,timg gei den. NO duqc toi tru hoi de cung cap kha nail can bang tai mOt each thong ke doi yeti met soItrqng 16n cac yeu eau nho do vo so may khach tao ra. Neu so may khach hoc cac ket not may khfich tao ra cac tai qua chenh tech nhau tren may chit, thuat toan can bang it se it hieu quit. Tuy ninon, unit don gian va toe dO cua thuet thin cho phdp cung cap hieu nang rat cao bao gom ca thong luqng cao va thei gian dip Ong ngiin trong met dai rOng cac img dung may khich / may chit thong clang. Be can biing tai xi: ly cac you cau ctia may khach bang cach din dui:mg cho met if le phan tram da ch9n nhOng yeu cau men cho timg may chit trong nh6m. Thuat toan !thong dap img nhftng thay doi ye tai tren mtii may chit (chling han nhtr tai CPU hay van de sir clang be nh6). Tuy nhien, qua trinh anh xa se duce thay d6i Ida quan he thanh vien trong nh6m thay d6i vi ti le phial tram tai phan b6 se duqc tai can bang. Khi xem xdt met g6i den, tat ca cac may chit thvc hien clang thai viec anh thiing ke de xac djnh nhanh cheng may chit nio se xi) ly poi do. Qua trinh anh xa sir dung mOt ham ngau nhien de tinh mirc tru tien dm may chit dva tren dja chi IP NIA cling den caa may khkh cimg cac thong tin trans thai khac de .t6i tru hoa viec can bing di. May chit tuong img se chuyen gal d6 tir the tang clued len tang TCP/IP con cac may chit khac se loai be goi nay. Qua trinh anh xa kh6ng thay d8i trir phi quan he gifra cac may chit trong nhOm thay doi, de dam bao rang dia chi IP vi cOng den cna may khach cho trutc se luon duqc anti xa den cang met may chi) trong nhom. Tuy nhien, may chit cu the trong thorn ma dja chi IP va cOng den dm may khich anh xa ten khong the duqc xac djnh tram do ham ngau nhien c6 tinh den quan thanh vien trong nh6m hien tai vi qua khir de toi thieu hoa kha nang anh xa lai. Nhin chung, chat Itrqng can .bing duqc xac dinh met each thong ke bed s6 luqng may khach tat) ra you cau. Nhu ket cau tang giarn ve so lucong may khach theo thong ke, sv deu don ye chat luqng cita thuat toan can bang tai se thay d6i nhe. De host di-ging can bang it co do chinh xac cao tren mil host trong nhom, met phan tai nguyen he th6ng se duqc sir dung de do va phan Ung Mr& nheng thay doi ciut dd. Str tra gia ye hieu rang nay phai duqc can nhac so yeti lqi ich cua viec tot da holt khil rang sir dung cac it nguyen trong nhOm (ve ca ban li CPU va bit) Trong bit dr twang hqp nao, viec sir dung hqp ly cac ngu6n tai nguyen may chit phai duqc duy tri de co the phvc vv cho cac tai may khach khk trong traimg hqp xay ra 16i. 32 Chuang 3: Thuat toga' can bang tai DI" Van Thjnh — A13439 Khi mOt may chit meri tham gia vao nh6m, n6 se kith hoat qua trinh hOi tu va mot quan hg thanh vien mai trong nhOm se duqc tinh town. Khi qua trinh hOi to holn thanh, mOt phin tai thieu may khkh see duqc anh xa tai host mai. BO can bang tai do cac ket not TCP tren mai host vi sau khi ket not TCP hiEn tai cua chfing holm thank, ket not tiep theo tir cac may khkh bj inh huong se duqc xir 15r btri host mai. Do d6, cac . host nen duqc bo suns vio nh6m nhftn thtri diem tai tang qui manh nham ten thieu hod hiEn turyng ngat quang cac phien. De trinh van de nay, trong thai phien phai duqc , quan bei 1mg dung may chit sao cho n6 co the duqc ten du true hay duce tra lai tir bat Icy mOt may chit nio trong nhom. Vi du, trong thai phien co the duce day den may chit ca sec dft lieu va lint trong the cookies dm may khach. 3.2. Gaol thieu mOt so thu#t twin can bAng tai 3.2.1. Thu#t twin Round Robin Day gqi 11 thuat than Ink chuyen yang, cac may chit se duct xem ngang hang vi sap xep theo mOt yang quay. Cic truy van dich vu se !An luqt duqc giri tai cac may chit theo this tir sap xep. Vi : Cau hinh mOt cum Cluster bao wim 03 may chit: A, B, C. You cau djch vu this nhat se duqc giri den may chit A. You cau djch vµ this hat se duqc giri den may chit B. Yeu cau djch vµ this ba se duqc giri den may chit C. You eau djch vitt this to se 1a1 duqc girl cho may chit A.... Nhu \ray b0 can bang tai se phan phai tai va giri you cau Ian WO den timg may chit thyt trong cum may chit. S6 ltrong cac truy van den timg may chit la ngang bang nhau, dieu nay dam bao rang cac may chit deu phai host dOng vii mOt cong suit ttrcmg tu nhu nhau. 3.2.2. Thu#t twin Weighted Round Robin Ban chit gitmg nhu thuat tom Round Robin, My nhien chung ta co the eau hinh cho mOt hay nhieu may chit nao d6 thutmg xuyen duqc sir dung hen, hay not each khic chting ta co the dieu chinh sao cho cac may chit ea Wing lye xir ly khac nhau. Mai mOt may chit den duct gin mOt tong s6, d6 la mOt gia trj so nguyen cho biet ding suit xis ly. Trqng so mac djnh la 1. Lay vi du, c6 ba may chi A, B va C &Km On tong so tucmg img Ian lusrt la 4, 3, 2. MOt trinh tu lap ke hoach se duqc clurc hien trong mOt chu ky, va cac truy van you cau djch vu se Ian luqt duce giri den timg may chi theo trinh tu nhu sau ABCABCABA. Nhu vay trong qua trinh thuc hiEn, mOt trinh tu da duqc tao ra Wan theo tong so tren mai may chit. 33 Chuang 3: Thuat toan can bing tai DO Van Thjnh — A13439 Thuat toan Weighted Round Robin khong can phai tinh den cac you cau ket not cho mai mot may chi, va chi phi lap ke nnanh la nho hem so veri cac thuat town ke hoach dong, no cfmg co the c6 nhieu may chi hcrn. Tuy nhien no co the dan den mat can bang tai Ong giaa cac may chi neu cac you cau tai qua Ion. Dieu d6 la co the bon hau het cac yeu cau deu duqc dinh hueng den mot may chi. Thuat than Round Robin la mot throng hqp dac Wet cua thuat Wan Weigth Round Robin, trong do tat ca cac trong so deu bang nhau. Chi phi cia viec tao ra cac trinh t1r lop Ice hoach khi sirs di); cac twig s6 6 min may chi la khong clang Ict. Ben vay khong nhit thiet chi sir dung thuat toan Round Robin. 3.2.3. Thu@ ban Least Connection Thuat toan Least Connection dua teen tinh toan s6 luqng ket n6i a thirc hien can bang tai cho may chi, no se lir dOng bra chqn may chi veri so lining ket not dang host dOng la nho nhat. Co nghia la n6 se djnh huang cac yeu cau nhan &lux tit mang den cac may chi v6i so luqng cac ket not duqc thiet lap la it nhat. Day la mot trona nhung thuat toan lap ke hoach ,d6ng, ben vi ne can phai tinh toan so cac ket not truc tiep cho men may chit. Khi mot so may chi c6 cing mot hieu suat xir 19 tucmg to nhtr nhau, viec 1#p ke hnach vat thuat toan Least Connection de Oki phoi tai nhieu yeu cau kha la "min" beri vi hau het cac yeu cau se khong ce co hoi de duqc djnh hyena den mot may chit nao khac. Nhin so qua, thuat toan Least Connection au% co the sir dung hi'eu qua ke ca khi co nhieu may chi co nang lye xir 15, khac nhau, bed vi may chit nhanh hon se c6 nhieu ket not hon. Nhung thuc te, no khong the lam viec that tot nhu vay beri vi trang thai TIME_WAIT cia giao thirc TCP thuemg chi keo dai 2 phin, trona khi 2 phit nay mot may chi may co luu luqng truy cap 16n thu&ng len den hang nein ket nen. Vi da may chi A manh gap d8i may chi B, may chi A dang xir 1S hang ngan yeu cau va Oa china lai o trang thai TIME_WAIT nhung lie nay may chi B cling dang chat vat de XII 1S, cho xong hang ngan nhang ket not cia no. Chinh vi vay, sir dung thuat toan Least Connection khong the can bing tai tot gifta cac may chi co kha 'tang xir 1S , khk nhau. 3.2.4. Thutit bin Weighted Least Connection Thuat toan Weight Least Connection ban chit gieing thuat toan Least Connection, nhung ching to co the cau hinh uu tien cho mot may chit trong curn may chi host dOng bang cach gan trong so cho mOi may chi. Nhitng may chi co gig tri tong so lem hon se nhan duqc ti le ket not 'Neu hon. Ngu&i quart trj mang co the du hinh phan chia Mpg so cho min may chit vet cac ket not mpg se duqc ten ke hooch den min may chit ma 6 do ti 10 phan tram cia s6 cac ket not hien then 6 men may chi la ti da cho khi thiet 1#p gan tong so. 34 Chuang 4: Thiet ke mang WA be can bing tai D6 Van Thjnh — A13439 CHVONG 4: THIET Kt MANG VOI BO CAN BANG TAI Trong chuang nay, chimg ta se tap trung vao viec then khai b0 can bang tai tren he thong mans, can nhic va lua chgn cac this& kE co lien quan. Can xay dung met , thitt ke giai quyet duce tinh sari sang cao, kha nang ma rang, kha nang quan va van de an ninh cho toan b0 he th6ng, dung then co the dam bao ,chiu dugc cac van de phat sinh khac nhau trong timg thanh phan mang khac nhau, bao germ ca an bang tai. Truerc, khi chimg ta di sau vao mat cau trtic ket mang cu the, chimg ta can bao quat mOt so khai niem ca ban. Bat dau veri cac van de cim b0 can bang tai dugc then khai nhu mOt bo chuyen mach lop 2 hoac mOt b0 dinh tuxen I6p 3, vi die!' nay di y nghia quan tang trong viec thiet ke mang. Sau do chang ta bat dau veri mot so mau thiet ke don gian ma kh8ng giai quyet duqc tinh siin sang cao. Tiep theo chimg ta thao Juan lam the nao di bey can bang tai lam viectheo cap de cung cap tinh sin sang cao, fru& khi chuyen sang de cap Ong rai cacthiet ke c6 tinh sari sang cao va dua ra nhthrtg can nhac lien quan. Chuang nay se co gang cho that' ,str phat trien caa cac nuo hinh mang khac nhau trai ngugc veri viec chi trinh bay mOt thiet ke mo hinh mang cu the. 4.1. BO can bang tai nhw lit mOt bQ chuyen mach so vtri mOt bO dinh tuyen Cac boat dOng co ban cim mOt b0 chuyEn mach la nhon get tin tren moat cong veto, xac djnh cac giao din dau ra, gui cac g6i tin tren cong ra. Lam the nao dE bo chuy . En mach xac dinh duqc giao din ra cho mOt gel tin can phy thuOc vao tong loai chuyEn doi. Ethernet lap 2 chuyen d6i sir dung dia chi MAC c6 sin trong lop lien ket da lieu coa met g6i tin (16p 2 trong m8 hinh OSI) de xac dinh cac cong giao din dau ra cho mOt g6i tin. MOt b0 chuyen mach 16p 3, ding dugc biet den nhu mOt bo djnh tuyen, sir dung thong tin lop mang (16p 3 dugc the hi'en trong mo hinh OSI) de xac dinh cac cong giao din dau ra dm met g6i tin. Khi sir dung giao thirc intemet, bo chuyen mach 16p 3 sir dung thong tin dia chi IP trong g6i tin de xac dinh cac giao din dau ra cac gal tin. May lchach va may chit thubng dugc ggi nhu la cac host, tra den b0 dinh tuyen qua mOt default gateway c6 dirt chi IP duce cung cep bed ngueri quart tri mang. Khi Wit host can phai girt mOt g6i tin den mOt, dia chi IP ma kh8ng c6 trong cling mot dja chi mang con cim ne, host se giri cac g6i tin den default gateway cim ne, default gateway dm be) dinh tuyen se sir dung melt giao thirc dinh tuyen d'E' xac dinh nai girl g6i da lieu du tren cac thong tin dia chi IP. BO can bang tai hoat dOng o lop 4 hoac cao hcrn phu thuOc vim cac tinh nang ma chin ta sir dung, Nhu da de cap, khi be) can bang tai nhan dugc mOt gel tin, g6i tin co dja chi VIP nhu la dja IP va dia chi MAC dm can bang tai la dia chi MAC dich. BO can bang tai se 35 Cliental, 166.1.1.100 0 141.149.65.1 MAC-MI Chuang 4: Thiel k'e mang veri b0 can bimg tai DO Van Thinh — A13439 xem xet thong tin tai lop 4 vi b ben trong g6i tin de xac dinh loai chirc nang can bang tai can [him hien. Bang each sir dung the thong tin trong cac g6i di lieu cling veri viec kiem tra tinh trang sire kh6e may chit va dieu kien tai may chit, b0 Gang bang , tai se xic dinh may dich cho you cAu. BO can . bang tai sfra &di cac throng can thiet trong goi tin, chang han ram dja chi IP dich va so ding TCP hoAc UDP. MOt khi &Ai tin da duqc sin ded, b0 can bang tai ,an phai xic dinh giao din dAu ra vi chuyen tiep gel tin. BO can bing tai co the chuyen tiep cac goi tin neu n6 la mOt Ns) chuyen mach holm mOt bo dinh tuyen tny thuOc vio no duqc cau hinh nhu the nao. Hinh 4.1 cho thay luu luqng goi tin va dia chi IP qua b0 can bang ma kitting thqc hien dinh tuyen lop 3. Default gateway cho the may chi' va b0 can bing tai da dutyc thiet l'Ap den b0 dinh tuyen tren. Cac may chu trong cling mot mang con, va do do c6 the giao tiep veri nhau thong qua viec can bang tai ma Ichong an phii lien quan den cac b0 dinh tuyen. Dieu quan frog la phai chu y IuOng cac gel tin to Rn lai cho may khich tir may chil dia chi MAC dich den Ml, dia chi MAC dm bij dinh tuyen. Tuy nhien ac may ch8 ce dia chi IP public n6i chung thutmg kh8ng dirge mong muon bed vi chting ta khong the brio ton doge kW:Mg gian dirt chi. Vies sir dung IP public tren cac may chi thirc se kitting the ngan chan mOt ngutri nio d6 muon truy cop tut tiep vao cac may chit, trir khi co cac chinh sach kiem soat truy cAp thich hqp dirge thuc thi tren bo can bang tai hoAc tren b0 dinh tuyen. Chung ta cling co the sir dung dirt chi IP private cho the may chit, nhung bAy gitr echang ta se co hai mang con khac nhau ket not ten cling mOt interface cia b0 dinh tuyen. BO can bang tai veri dia chi VIP public la mOt mang con vi the may chi WA dia chi IP private li cac mang con ;chic nhau. Ching ta can phai xac dinh hai dja chi IP tren b0 dinh tuyen ket not veri can bang tai: mOt Ii dirt chi IP trong mane con cia dia chi VIP va cac dia chi khac trong mang con dm the may chi. MOt s6 sin pham can bing tai c6 the cung cap cac tinh Ming nham tranh sir can thiet khi xac dinh dia chi W tren interface cia b0 dinh tuyen. VIP 141.146.66 MAC-642 Source IP Oset IP Soures Dee MAC 1 106.1.1.100 141 .149.66.3 ml 142 2 110.1.1.100 141.14985.11 11411 M4 9 141 14966.11166 1 1 100 644 MI 4 141.i49.65.3i96.1.1 100 614 MI Dealt gamey for servers is at b Me IP address on Ire totem ewers — 141 .140.65.1 RS1 141.14965.10 MAC-M3 RS2 141.140.65.11 MAC-164 Hinh 4.1: Bo can bang tai khong Mm nhiem vu clinh tuyin 36 14114966.1 MAC• MI 0 Chuang 4: Thiet ke mang veibt) can bang tai DO Van Thinh - A13439 Hinh 4.2 cho they luting g6i tin vi dja chi IP veri cAu hinh hrcmg to nhu trong hinh 4.1, nhung cac default gateway cho cac may chit duct thiet 1{ip den dja chi IP ten be can bang tai. BO can bang tai hoat dOng nhu met be dinh tuyen chuyen tiep cac g6i tin met cach thich hop. pia chi IP default gateway duqc thiet 1.#p 1# 10.10.10.1. nhu duqc djnh nghia b tren cac cong giao dien be can bang tai ket not den cac may chit. Bari vi default gateway tren dm may chit duqc thiet 1(ip den dia chi IP tren be can bang tai, cac g6i tin tra len dm may chit se c6 dja chi MAC dich M2 ctia be can bang tai nhu trong hinh 4.2 own- Isti.1.1oo VIP R 141.149.663 MAC 1442 CIMetway IP-10.10.10 Sousa P Dest P Son MAC OM MAC t 100.1.1.100 141.149053 MI 142 2 106.1.1.100 10.10.10.20 es.1 0/12 M4 3 10.101020 11111.1.1.100 M4 V2 4 141.149. 190.1.1.100 M2 MI 0 WW1 often for movers Is eel lots load bolsocers P address- 10.10 10.1. RS1 RS2 10,10.10 10 10,10 1020 MAC-M3 MAC 4.14 Hinh 4.2: Bo can bang tai hoot (long nhu bo djnh tuyin Chat nang dinh tuyen hoac chuyen mach thuc sir rieng biet so veri town be cac chin nang dm be can bing tai. CA djnh tuyen vi chuyen mach deu xac djnh hop tiep theo vi giao dien dau ra dua ten dia chi IP vi dja chi MAC. Neu cac may chit thin vi be can bang tai cling mang con hoc mien quang ba, be can bang tai c6 the thuc hien chuyen mach lerp 2 de giri cac g6i tin den cac may chit thuc, !feu be can biing tai yi cac may chit thut kh8ng nam trong cling mien quartg ba , cac gal tin sau d6 duce chuyen tiep den may chit thuc se biphu thuec vio be can bang tai ceo chirc nang cue b0 chuyen mach dm 16p 2 hay 16p 3. Neu be can bang tai nhu met be chuyen mach 16p 2, be can bang . tai se giri g6i tin den default gateway dm na vi g6i tin se duqc giri den may chit thuc. Neu be can bang tai nhu la met be chuyen mach lerp 3, net se cac djnh hop tiep theo dua tren bang djnh tuyen. Ngoai ra neu be can bang tai hoat dOng nhu met be dinh tuyen 16p 3, se c6 met lqi ich rat quan tong, cac may chit c6 the 1r6 den be can bang tai nhu la met default gateway cue n6. Dieu nay dam bao rang cac luring g6i tin tra Ibi tir may chit se phai thong qua be can bang tai. 37 I VIP•.141.149.65.3 MAC M2 Gateway IP-10.10.10.1 Load Balancer Swat* 12 Chuang 4: Thiet ke mang yeti be can bang tai DI) Van Thinh — A13439 Trong phan con 13i cua chuang nay, chi mg ta se xem xet cac tin& ke trong do be can bang tai duqc sir dang nhu met be djnh tuyen, default gateway cho cac may chit co the duqc thiet 18p den ilia chi IP dm be can bang tai. 4.2. Cie thiet ke Han gain Bay gia chimg se de cop ve met s6 thiet Ice mpg don gian cho viec trien khai , m0t can bang tai ma khong giii quyet dtrqc tinh san sang cao. Sau d6 chting ta se phat trien nhftng thiet ke co ban de giai quyet san sang cao. Thiel ke don bang nhu trong hinh 4.1 va 4,2, trong do cac may chtl &Km ket not mit tiep den 130 can bang tai. Cac may chit thutmg duqc ket not den .b0 can bang tai bang cach sir clang cac ket 100-Mbps va b0 can bang tai duqc ket not yeti the be djnh tuyen bang each sir clang lien ket 100-Mbps hok lien ket gigabit. Chimg ta ding co the ket not tat ca cac may chit can bring tai yeti cac ket gigabit, va sir clang hai hoc nhieu lien ke't gigabit router. Thiet ke nay giffri hart s6 lucing may chit WA so luqng cong c6 san tren b0 can bang tai. Mot dO cong tren men san pham can bang tai 11 khk nhau, mot do cong va gia cho mot citing tren b0 can bang tai ding c6 the kh8ng eon nhu ctia N chuyen mach 16p 2 hay lop 3. VI vay, Ihieu khach hang trien khai mot be chuyen mach 16p 2 de ket not cac may chit, va be chuyen mach lap 2 Mn ltrqt ket not den be can bang tai thong qua lien ket 100-Mbps hok gigabit, nhu the hien trong hinh 4.3 Client-188.1.1.100 I C I 141.149.65.1 MAC=141 10.10.10.10 10 10.1020 MAC ••143 MAC M4 Hinh 4.3: Cac miry cirri drew kit nil thong qua bo chuyin mach lop 2 38 Client • 1114.1.1.100 141.14945.1 MAC-MI traffic addresord to VIP Vfl ,, 141.14!.653 MAC 1,412 Gnaws 1Pat 10 10.10.1 r 10.10.10.10 it o.1020 MAC -M3 MAC- M4 RS I RS2 frank addressed to oral miners 141.149.65.10 through 141.149.65.12 Applicators nor configured for load balancing 141.14945.10 through 141.14945.12 Chuang 4: Thiet ke man ved Kt can bang tai DO Van Thinh - A13439 Trong thiet Ice dugc hien thj o hinh 4.3, tit ca cac luu lugng den cac may chi chat' theo luong thong qua 130 can bang tai. Nhieu may chi khac nhau deu dugc ket not den b0 chuyen mach lop 2 tilt nhUng may cha nay clang chay nhang fmg dung khong nhat thiet phai thong qua b0 can bang tai. Trong thiet ke nay, cac luu lugng truy cop den cac may chit deu th8ng qua No can bang tai. Tay thuOc Nth° cac sin pham can bang tai, kien trim cia no va hieu suit, cluing ta c6 the gap phai mOt so nut c6 chai o trong thiet ke nay. Neu citing ta mon tranh viec grid luu lugng khong can thiet thong qua 130 can bang tai, cluing ta co the di den thiet ice mOt canh tay nhu trong hinh 4.4. Thiet ke nay thuang duce sir dung trong thuc to di c6 hieu suit cao hcm, hoc de tranh djch dia chi mang cho mOt s6 loci ing dung 'that djnh. Trong thiet ke mot atilt tay, b0 can bang tai dugc ket not nhu mot canh tay dEn b48 chuyen mach Idp 2. Tat ca cac may chi vOi cac ing dung dugc cau hinh cho can bang tai dugc gin dia chi IP private. Tat ca cac may chit nhung may khong can can bang tai dugc gan dja chi IP public v6i default gateway trO den dja chi 141.149.65.1 dm b0 djnh tuyen. Chi c6 luu lugng truy cop girt den dja chi VIP mai qua b0 can bang tai. Hinh 4.4: Thiet ice mgng m 'en tay 4.3. Thiet ke cho tinh sin sang cao NEu mOt may chi hong, hi) can bang tai co the phat hien thong qua cac cuSic kiem tra firth trans sic khoe va djnh htreng luu lugng den cac may chi thay the. Nhung (lieu gi se xay ra neu 130 can bang tai bj 10i? Trong phin nay thing ta se xem zit va lua chQn mo hinh thiet ke dam bito dugc tinh sin sing cao, chju dung dugc cac su co khac nhau bao gom ca can bang tai. 39 Chuang 4: Thiet ke mang vtri b0 can bang tai DO Van Thinh — A13439 BO can bins tai c6 the lam viec thanh cap theo hai cach khac nhau: the dO active-standby hoac lit che dO active-active. Trong the di) , active-standby, mot can bang di . se char dv phong trong khi cac chtic nang caa b0 can bang tai Ida se hoat dOng. Trong che dO active- active, ca hai b0 can bang tai deu thvc hien nhiem AI can bang tai va hoat Ong sao luu cho nhau. Vic sir dung cling lac hai b0 can bang tai 6 ding mot vi tri de cung cap !chit nang chju 161, trash str co khong phai la mot khai niEm men trong khong gian mang, van de nay da dugc then khai nhieu tren nhieu thiet bj mang !chic cha ha ► nhu tren bq djnh tuyen. 4.3.1. Active - Standby Cau hinh active-standby lien quan den hai b0 can bang tai lam viec o the dO mot dv phong va mot hoat Ong, nhu trong hinh 4.5 Active WI VIP- 111.14110 10 MAC -.1111 Gateway W 1010101 I 141.149011 sun I Dedlease4J brat for loot MK .411 774 ,,,-*"i balawer conflation „ Swab, us ad-7 I tad VIP- 141.14145.10 Balsam 2 MAC- YS Gateway IP = 10 10 10 I 103010 N 10111 1020 10.10.10-30 10.10.1040 MAC-MS MAC .M7 MACs1011 MAC • le RSI RS2 RS3 RS4 Hinh 4.5: Hoot &Ong czia chi do Active-Stanby D6i vtri vi du nay, Chang ta thiet thiet ke mot b0 dinh tuyen 6 phia mite cac b0 can bang tai va mot b0 chuyen mach 16p 2 6 phia sau de ket not tat ca cac may cha. BO dinh tuyen vi b0 chuyen mach co the coi nhu la nhemg diem duy that tren thiet ke c6 the gap phii cac sv co ma khong co phucmg an dv phong, chung ta se gild quyet van de nay sau. Bay gib, chung ta se tap trung vao ‘ liun the the nao clam nang active-standby hog dong trong cac b0 can bang di. BO can bang tai dtr phong se khong dap ling bat Ick yeu eau girl den no va se khong xir ly bat Ick Itru Itrung truy cap nao. Trong khi do b0 can bang tai dang 6 the dO hoat dOng ser hall VIP se quang bit vi dip 1mg cac yeu cau truy van ARP. Citc truy van ARP dugc sir dung de lien ket cac dia chi IP vtri dia chi MAC. Bang cac tra ltri cac 40 Chuang 4: Thiet ke mang yeti 60 can bang tai DO Van Thinh — A13439 truy van ARP va quang bra chinh n6 voi cac ARP khac, b0 djnh tuyen va cac may chit se nhan ra dja chi VIP va lien ket dja chi MAC dia be can bang tai dang hog dOng tree giao dien mang de ket not den. Dieu quan tong lit ix) can Wing tai co mot dia chi IP wan 19 khac veri dja chi VIP. Dia chi IP guan ly et bet can bang tai thuang duce sir dung cho viec cau hinh va quan ly b9 can bang tai. Neu chting ta can truy cap den biti can bang di sir dung Telnet, chimg ta can sir dung dia chi IP quart 15/ nay. Mac di" be can bang tai do phong khong so but dja chi VIP, nhung n6 van dip img ARP cho dia chi IP quan 1Y de chting ta co the cau hinh va quart 19 cac don vi do phong. BO can bang tai hoat dOng vi do phong duqc ket not yeti nhau thong qua mot lien ket rieng vi viec kiem tra fifth trong sirc kh6e cite mot thiet bi duqc th8ng qua mot giao thirc dac biet gifta chimg. Nei chung cac ,b0 can Wing tai throng sir dung ket rieng nay cho viec kiem tra khee va tranh bat Icji so chuyen tiep du lieu tren lien ket nay. Trong trueing hop active-standby, cac a gei de lieu IA chan tren ket nay, vi b0 can bang tai hog dOng che de ch6 charbat cir yang lap 616p 2 chuy'en tiep den. Neu lien ket rieng gift hai b0 can bAng, tai bi cac 130 can bang tai phai c6 gAng sir dung mot duerng din thay the sin c6 kiem tra tinh tang six kit& ciut nhau. Trong hinh 4.5, cac bo can bang tai do the sir dung dutmg din ,theing qua be djnh tuyen hoc thong qua b0 chuyen mach 16p 2 de tiep can nhau. MOt so sin pham can bAng tai c6 the cho phep hai hay nhieu lien ket dugc cau hinh nhu met Whom trunk sir dung nhu mot lien ke.... Thiet ke nay kheo leo khi sir dung cac dja chi IP private cho cac may chit chi tin. Neu chin% ta sir d‘mg bo chuyen mach 16/3 ,2 de ket tbi the may chit, thi sau d6 cac ,b0 djnh tuyen phai duqc can hinh de djnh tuyen den the dja chi IP private. Ching ta ce the sir dung thay the bo chuyen mach 16p 3 bang b0 chuyen mach 16p 2 de cung cap kha nang dinh tuyen tir bo djnh tuyen dEn cac may chit v6i dia chi IP private. Cach tiep can thin hai, chin ta c6 the rang bubc mai dja chi VIP den mot min so may chit, va thiet lap default gateway den cac bo can bang tai ttrcmg ling. Neu chin% ta gan VIP1 den RS1 va RS2, default gateway cho RS1 va RS2 phai phat duqc thiet lap den IP1 de dam bao luting hit Wong tra 1Cri thong qua 1.30 can bang tai 1. Neu bb can bang tai , 1 gap phai sir co, b0 can bang tai 2 se phvc vv hai dia chi VIP va cling c6 the to cap kha nAng chuyen clOi dlr phong co trang thai trong khi sir dung tat ca cac may chit de can bang tai. Trong cach can hinh nay, lien keit gifa b0 can bang tai vi bo chuyen mach 16p 2 phai bane thong thich hqp bed vi cac xeu cau bang th6ng duqc tanglen. Cacyeu cau di fir b0 chuyen mach lop 2 den bo can bang tai vi tr6 ra tir bo can bang tai den bb chuyen 52 Sundt, Unit YIP-111 141.65.10 MAC-MI Gateway — 10.10101 YIP-141.149.65 10 MAC grin Balancer 1 toad Caws) W-10 10 10 1 Chuang 4: Thiet ke mang vtri NI can bang tai DO Van Thinh — A13439 mach Itrp 2 den cac may cha ‘thvc. Cac luting tra 16i se quay trtr 10 b0 can bing tai sau do den 130 chuyen mach vi roi den Ix) djnh tuyen trtrac ,khi tai may khach. goi tin yOu cau va tra lm se phai vuqt qua hai Ian thong qua lien kat gifra chuyen mach lop 2 va can bang tai. Chung ta dang. giai quyet van de nay bang cach sir Ong mot nhem trunk giaa can bang tai vi b0 chuyen mach bang each sir dung cac lien ket toe dO cao ham (gigabit). Ckh tie)) can thir ba, chung ta co the sir Ong NAT nguOn va ring bur)c bat ky dia chi VIP nao den bat kY may chit thvc Nth &Km tinh than linh host day di". Tat ca cac gei tin you cau va tra 16i se di qua hai Ian b0 can bang tai vi bo chuyen mach lop 2. Nhin chung ckh hieu qua nhAt la sir dvng ,DSR trong thiet Ice nay txii vi no cung cap thong luting cao cling nhu luting tau luring toi uu khi six Ong lien kat. Trong cac thiet ke da duqc chung ta de cap din, cluing ta mai chi sir Ong mot card mang trong moi may chi" ket not den N can bing tai hoac b0 chuyen mach 16p 2. Khi chimg ta ket non may chit den 1)0 can bing tai, chting ta se mat cac may ,chil neu b0 can bing tai gip phai sv co. Do d6. Chung ta sir dung b0 chuyen mach lop 2 de ket not den cac may chit va glop cho cac may chit co the duqc truy cap tir cac b0 can bing tai. Neu 1)0 chuyen mach lap 2 gip phai van de, chung ta cling se mat guy& truy cap den cac may chief. Hinh 4.14 the hien mot thiet ke yeti hai card mang trong moi may chit , de duy tri quyen truy cap den cac may chit neu co *it hi) can bing tai gap phai sv co ; Dieu nay cling bao vg guy& truy cap den may chit' va tinh salt sing cao mia may chit nett lien ket den may chit hoac mot card mang nao d6 tren may chit gap sv c6. latter In - 141.141.41S3 YrtllY Irte141.1410 GSA 141.14365 1 141.1065 MAC-MI MAC at /A2 g1 if III talcum se. 10.1010.36 1010.10.40 SAC-MS MAC-Mi MAC-M1 MAC =Mg RS ► RS2 RS3 RS4 Hinh 4.14: Tinh siin sang cao #7 53 Chuong 4: Thiet lee mang voi bi can bang tii DO Van Thinh — A13439 Sir hai card mang trong met may chi can dam bio firth chinh xac khi nang hoot deng doing thii dm card mang. Dieu nay pho thuec vao tirng loai sin pham va he' dieu hanh duqc sir (long trong moi may chit Met so loci card mang co hai cling vi ca hai Gong cling hoat deng ding thtri hoOc hoOc met cling hoot deng nhu la met ban sao luu cho met ding khac. MOt so nha cimg cap card mong co the lu!) trq kha nang nhom hai card mang ding nhau nhu met cep hoat deng h the de active-standby hoOc active-active. Trong thiet ke duqc the hien trong hinh 4.14, m81 may chi co hai card mpg. cac interface nay co the ding nand tren met card mang hoc hai card mang khac nhau. Tuy nhien, ca hai interface duqc nh6m Iii vao met clip hoot dOng h che de active-standby, card hoat deng duqc ket not den be can bang tii hoot deng vi card do phing duoc ket not den be can bang tii du phong. Khi bk can bang tai hoot deng gip phai so co, be can bang tai do phong se tiep quan. V(i): neu be can bang di do phing tiep quail lieu rang cac card do phing se hoat dOng? Neu no ;thong hoot deng, be can bang tai do phing se !dieing co duong mang truy cap den cac may chi]. Dieu kien de ail cho interface do phong tiep qu n pho thuec vao nhi cung cap card mang, cac trinh dieu khien phan mem cho card mang, vi he, dieu hanh dm may chit Dieu quan tong can luu Y rang be can bang tai hoat dOng c6 tile gip phai so c8 bang nhieu cach Ichic nhau. Met truing hqp de ding la khi be can bang tai hoat dOng co the bi mat dien, card mpg che de hoot Ong c6 the de ding phit hien th8ng qua trang thai, kit vi doll card mang do phing. Mot truerng ,hqp kW) khan hon la khi be can bang tai hoat Ong bi treo do 18i phan cimg hoat phan me trong trinh dieur khien hoOc quan ly. Trong truing hqp nay se khong co luu luring truy ?Op tren cac ket not hoot deng den may chi, nhung do tong thai lien ket ‘van kh8ng co van de $t c8ng phan cimg tren be can bang tai van On djnh. Be can bang tai do ph6ng se tiep quin nhiem vi can bang tai b?ri vi no khong they tin hieu dip tir qui birth kiem , tra tinh trang sirc khie den tir be can bang hoot dOng. Neu interface do phing kh8ng clang thai tiep quin, be can bang tai do phong se khong ci each nao truy cop den cac may chit Met van de khac trong thiet ice nay li neu card mons 6 the de hoot deng hoc lien ket den card mango the de hoat Ong co the Op phiti so co tren met hoc nhieu may chi gay ra card mang dµ phong se tiep quan nhiem vv. Be can bang tai hoot deng se tiep tic chat nang nhung se kheng co truy cOp nio den cac may chi neu be can bang tai do phing khong chuyen tiep hni luqng thong thtrang. Nhin chung, thiet . ke nay de bi 18i vi nen tranh sir (long trir khi dam bio duqc cac dieu kien xung quanh de giai quyet duqc cac van de xay ra. Trong thiet ice duqc the hien trong hinh 4.15, cac interface hoot deng tir cac may chi duqc phan chia gifta hai be can bang tii. Chang ta can tau hinh cac be can bang tai trong the de active-active vi rang buec djac chi VIP1 den RS1 vi RS2, vi dja chi VIP2 den RS3 vi RS4. Thiet lOp dia chi default gateway cho RS1 vi RS2 den IP1, va cho RS3 vi RS4 den IP2. Khi ca hai be can bang tii ding lam viec, chiing ta se co the s* ding tat ci cac be can bang CIi vi may chit Neu b9 can bang tai 1 gip phai so co, dja chi VIP I vi dja IP1 se duqc tiep quin boi be can bang tai 2. Nhtmg quan trong can dam bio rang interface card mang hoot Ong duqc ket n6i din be can bang tai dang hoot Ong (be can bang tai tiep 54 rel • 141 141.61/0 Antre Yin- Ill 141 6311 Sardby Gen, IP1 II 10 III 1114 • 141.111.46 111Sungby Vitt -141 ISIS n Mime Camta, 1P2 1010102 Chuang 4: Thiet ke mpg yeti be• can bang tin DO Van 'Minh — A13439 quan tir be can bang tai g#p phai sv c0) a cling met then diem de cung cap ket not den bp can bang tai 2. Nhu da de cap trong thiet ke hinh 4.14, nhung met cat tien trong thiet ke nay IA neu , met trong cac interface card mpg hoat don? gap phai sr co, interface dv phong se tiep quan de cung cap ket not thong qua be can bang tai khac. Neu interface card mang hoat dOng a may chit RS 1 gap phiti van de, b0 can bang tai van se truy cap den RS 1 thong qua be can bang tai 2 beri vi khi chimg ta sir dvng che de active-active, be can bang tai 2 cling se chuyen tiep luu lugng. Khi cluing ta thiet lap default gateway cho RSI den IP I, luu lung tra leri may chit van se thong qua be can bang tai 1. Neu default gateway dugc thiet lap de djnh tuyen thay vi IP nguem cita be can bang tai, cluing ta se co met luring tra 16i bit doi ximg. War in ..141.14.163 %UP 1P2 .041 143664 141 1066 1 141 10 MAC•141 MAC 012 1010 1010 1111111211 1•14111120 141101140 MAC-116 MAC a In MAC-10 MAC 151 RS2 145 RS! HInh 4.15: Tinh sang cao #8 Chang ta co the tan dung viec chia se dja chi VIP trong thiet ke nay trong do ca hai be can bang tai co the xir 157 luu lugng cimg met lOc cho cling met (ha chi VIP. Veri viec chia se dja chi VIP, cluing ta khOng phai lo lang lam the new luu Ku:mg tra leri quay tra lai va lieu default gateway duce thiet 1#p dting. Chimg ta co the rang bueic moi dja chi VIP den tit ca cac may chit va bit cu be can bang tai nao nhon dugc gel tin dau tien se xis ly no. Trong thiet ke dugc the hien trong hinh 4.16, cluing ta se de cop den cac card mang hoat dOng a che de active-active, trong d6 ca hai interface hoat tong cling met hic. Dieu quan trong can luu ST rang dja chi IP moi may chit thvc phiti trong gi6ng nhu met may chit thvc den be can bang tai. Phu thuec veto he dieu hanh train men may chit, chimg ta can cau hinh dja chi IP cho interface card mang. Vi dv, Linux cho phop cac dja chi IP cho ca hai interface card mpg cling chung mot mpg con. Met so hg dieu hanh co the you du rang cac dja chi IP cho hai interface card mane phai train mang con khac nhau. Chang ta can phai kiem tra lieu chimg ta co the thiet 1#p default gateway cho mtii interface card mang hay khong. Neu he dieu &nth chi cho phep mot default gateway dugc thiet lip, tit 55 141 1001 141 1045.2 V1P1 n 141_1 We a Standby VIrt- 141 10021 AS.. Gatnrin *Isla 10 10 2 VW's. 1 41.10.0.20 4rftny VW? - 141.1011121 Standby Garay WI -.10 10 10 1 Chuang 4: Thiet kt mang veri hi) can bin tai Do VAn Thinh — A13439 ca cac get tin tra lati se thong qua cimg. mot default gateway vi dieu nay , gay ra luting luu lucmg bat doi ximg. Do 46, each tot nhat la sir dung DSR hoac NAT nguon khi ket not cac may chit den nhieu be can bang tai sir dung hai hay nhieu interface card mang trong may chit, trir khi chung ta hieu chinh xac hg dieu Wirth va hoat dung dm card mang. %UP J 1-141.1Mf03 VRRP Q2-141 100 4 WM It 10 141.10.141,1 10.101020 tt 10. IRO 14AC•115 MAC 412 MAC • 5111 MAC n 101 R52 103 RS4 Hinh 4.16: Tinh sin sang cao #9 Khi mot card mang gap phai stir co, bo can bang tai s6 xem xet may chit thvc ducm xitc dinh ved dia chi IP tren card mang do, sau 46 may chi, thine tiep tvc hoat dOng thong qua card mpg thin hai. Nhin chung, interface card mang trong the dO active-active ce the gay ra cac van de nhu da d'e cap. 43.7. Si giao tiep gifra cac bq can bang tai Cho dit cluing ta sir dung the de hoot dOng active-standby so active-active, cac be can bang tai van se giao tiep ved nhau bang each sir dung met so giao thine. Khi sir dung cau hinh active-standby, cac be can bang tai can xic dinh .b0 can bang tai lam viec the d¢ hoat dOng va the dO du phOng. Thy thueic vao sin pham can bang tai, dieu nay c6 the, van de nay c6 the la met eau hinh bang tay frac tlr dOng. gifta hai bo can bang tai. Trong the dO cau hinh active-active, min bi) can bang taiphai xac dinh cac dja chi VIP hoat dOng va cac dja chi VIP dy phong tren mot be can bang tai. MOt each tiep can phirc tap hon se duqc xem xet khi be can bang tai ce duqc sv phuc vv tot tin met dja chi VIP dtra vao nang lye sin co tren mid bo can bang tai. 56 Chuang 4: Thiet ke mpg voi 1)(1 can bing tai DO Van Thjnh — A13439 Dieu quan tong la hai tiep can bang tai hoat dOng trong ciu hinh co tinh san sang cao co mot con duemg giao ti clang tin coy giffa chimg. Twc tiep ket not hai NO can bang tai ding nhau th8ng qua mot idiom trunk cita hai hoOc nhieu lien ket de dam bao thong tin lien 1pc dang tin 0y, trir khi chimg to dang d8i phe veri mot thiet ke da duot trinh bay trong hinh 4.13. Nhin chung, mOt san pham can bang tai tot nen sir dung tat ea cac ,dtrang dan co san de giao tiep sled mot1)0 can bang tai !chic neu tat ca cac ket truc tiep gitta hai l%) can bang tai gap phai str co vi mOt ly do nao do. 57 Chacmg 5: ciu hinh cal dat vi thir nahiem CHU'ONG 5: CAU HINH CAI HAT VA THU' NGHItM 5.1. Gifri &Fitt DO VAn Thinh - A13439 • HAProxy la phin mem mien phi, cung cep cac giii phap mang tinh sin sang cao. HAProxy rat nhanh va tin cjy cho cac Ung dung TCP/IP, dec biet la HTTP. No thich kip cho cac trang web hog Ong tai cao, hog dOng yeti hang chuc ngin ket • Giai phap HAProxy giai quyet ducyc cac nhu au hien nay nhu: can bing tai cho cac trang web hog dOng tai cao, dam bao cho djch vv web hog dOng lien tvc ngay ca khi c6 cac sv c8 ye logical hay vet 19 xay ra. MO kink HAProxy 5.2. TOng quan HAProxy lsibt fang itã try HAProxy duce hi) try ten cac nen tang he dieu hinh nhu: Linux 2.4 on x86, x86_64, Alpha, SPARC, MIPS, PARISC Linux 2.6 on x86, x86_64, ARM (ixp425), PPC64 Solaris 8/9 on U1traSPARC 2 and 3 58 Chuang 5: cau hinh cal dat vi thin nghiem DO Van Thinh — A13439 Solaris 10 on Opteron and U1traSPARC FreeBSD 4.10 - 6.2 on x86 OpenBSD 3.1 to -current on 1386, amd64, macppc, alpha ... Char nang • Dinh tuyen cac yeu cau HTTP (Kra ten cac cookies chi duqc chi dinh sin; • Can bang tai de dam bio cac may chit host dOng lien tpc bang cach su dung HTTP cookies • Chuyen d8i sang may cho du phong ngay khi may chn chinh gap su co • Chap nhan cacket not den cac ding chi dinh sin phuc v4 cho viec theo dOi iru diem • Cung cap cac giai phap can bang tai, proxy nhanh vi tin cay • Nang cao tinh bao mat cim he thong • Nang cao hieu nang vi tinh an than cfut 4 th8ng nhei chirc Jiang can bang tai vi sao luu du phong. Khuyit diem • Lam tang chi phi khi trien khai he th8ng • He th8ng phIrc tap ham nen se kho khan trong viec van hanh va bao tri 5.3. Chi dot giiii phi!) HAProxy cho may chi' Web teen CentOS 5.3.1. Thiet Ice h? thOng 59 Chuang 5: cau hinh cai dat va thir nghiem DO Van Thinh — A13439 HAProxy co dia chi 192.168.10.10 May chit 1 chay WebServer 1 va Database c6 dja chi IP 192.168.10.11 May chit 2 chay WebServer 2 NIA Database c6 dja chi IP 192.168.10.12 HAproxy, may chit 1 Nth may chit 2 ding sir dung mOt dia chi IP a° la 192.168.10.15 5.3.2. Hoot Ong Khi may lchach c6 nhu au ket n6i toi may chit Web, se kat n6i vao dia chi 192.168.10.15 . Khi d6 ket not se tr6 tai HAProxy. Sau d6 HAproxy se Olen tai ye may chit 1 vi may chit 2 Neu may chit 1 hoac may chit 2 gap phai sr co thi HAProxy se tr6 kat not ye may chit con lai Neu HAProxy gap phai van de thi kat not dm may khich den dia chi 192.168.10.15 se tr6 truc tiep den mOt trong 2 may chit 1 vi may chit 2 5.4. Chi city au hinh 5.4.1. Chi '1St au hinh HAProxy Download haproxy # yum -y install haproxy Xem phial.' bin cai dat haproxy # rpm -qa I grep haproxy du nth HAproxy # vim /etc/haproxy/haproxy.cfg default listen webfann 192.168.10.10:80 mode hap stats enable stats auth admin:admin stats uri /haproxy-status stats refresh lOs stats hide-version balance roundrobin cookie JSESSIONID prefix option httpclose option forwardfor option httpchk HEAD /check.txt HTTP/1.0 server webl 192.168.10.11:80 cookie A weight 70 check server web2 192.168.10.12:80 cookie B weight 30 check 60 DO Van Thinh — A13439 thinhdy'l server: home thinhdv _ 7 X pie Edit ylew imTNInal Tabs yelp maxconn 68089 retries 3 listen webfarm 192.168.10.10:88 mode http stats enable stats auth admin:admin stats uri /haproxy-status stats refresh 10s stats hide-version balance roundrobin cookie SERVERID insert indirect cookie ISESSIONID prefix option httpclose option forwardfor option httpchk HEAD /check.txt HTTP/1.0 server webl 192.168.10.11:80 cookie A weight 70 check server web2 192.168.10.12:80 cookie 8 weight 36 check I main frontend which proxys to the backends a backend static balance roundrobin server static 192.168.10.10:80 check thmhdv7server home thrthdy pie Edit Veva pinta' Tabs Help * static backend for serving up images, stylesheets and such backend static balance roundrobin server static 192.168.18.10:80 check * round robin balancing between the various backends backend app balance roundrobin Kheri dOng Haproxy # service haproxy start 5.4.2. Citi dirt dich vy WebServer tren Server 1 vit Server 2 Tren hai may chit cai dat djch vg Web va deu chay c6ng mac djnh x Chuang 5: au hint' cai dat va thir nghiem 61 Chuang 5: cAu hinh cai dat vii thin nghiem DO Van Thinh — A13439 Ngoai ra can to 1 file check.txt trong thu mpc /var/www/html de HAProxy doe trong thai caa 2 web server # touch /var/www/html/checktxt # echo "Web Server [1]" > /var/www/html/index.html # service httpd start Truy cAp /haproxy-status trinh duyet Web se you cAu nhop uesr/pass daa vao tep thu hinh HAProxy. Statl,,- tics Report for HAP rory Fi onlla Flrefor x de Edit yiew History fioolanarics "lois Help Ej Statistics Report for HAProxy a Vial" roanrerl „,„ , .51,41 * ♦ I ji92.169.10.10Thaproxnutusi - si ti- gil A HAProxy Statistics Report for pid 25794 > General process Information pia (harm .25724 (flan PI, Manx • 1) 41/0014 atm: manna.. unlimaild. uliman . IOU auosaak • ODA maw • 4031 aulapipet .0 Who UP laclusp UP awlsanis: 'SW (mann wave UP. going dawn Inaba/ U0 li 0•2 dam, • 12112:220USea • mania = • glabilatme • liming i.0 wive CONN. gang up Isclomp DOWN. gong up len •• gehne many "".” came Running Praamd ' 1 Caney.' PIM. 00 INS Mt 1 2 N. 1 2 earn scan UP Int 75 a 104130 haci • 41 C04,04 Sluicing Mt Cal ambled 0 na circled a impend 0 al a "Nat • maw OPEN 02111 0 0 • 0 1 0 1 a a • 23 MO 0 0 0 a 0 Mt UP 70 r 0 0 well 0 0 0 - a 0 0 0 0 0 0 0 0 28102 UP 10 V 0 0 at land 0 0 0 1 0 1 ea 2 2 ••1 10 00 a 0 0 0 0 0 2mlb UP 10) 2 0 0 5.43. Cid Sat va citu birth KeepAlived trio Haproxy, Server 1, Server 2 Download KeepAlived # yum install libcrypto.so.4 -y # rpm -ivh keepalived-1.1.13-5.e14.rf.i386.rpm Cart hinh keepalived # vim /etc/keepalived/keepalived.conf vrrp_script chk_httpd { script "Wall -0 httpd" interval 2 weight 2 vrrp_instance 62 Chuang 5: cau hinh cal dat va thir nahiem DO Van Thinh — A13439 interface eth0 state MASTER virtual_router_id 51 priority 150 # 150 master on HAProxy; 120, 100 backup on server], server2 authentication auth_type PASS auth_pass 123456 } virtual_ipaddress 192.168.10.15 } track_script { chk_httpd } } thinhclv :server home thInhchr The Edit mew Serval labs help vrrp_script chk_httpd { script "killall -8 httpd" interval 2 weight 2 } vrrp_instance VI _1 { state MASTER interface eth0 virtual_router_id 51 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.18.15 } track_script { chk_httpd } } virtual_server 192.168.208.180 443 delarloop 6 CAu hinh HAproxv voi Ao # vim /etc/haproxy/haproxy.cfg default 63 thinhdv 1 server home thinhdv Ede Edit ylew Terminal Taps Help listen webfarm mode http stats enable stats auth admin:admin stats uri /haproxy-status stats refresh 10s stats hide-version balance roundrobin cookie SERVERID insert indirect cookie JSESSIONID prefix option httpclose option forwardfor option httpchk HEAD /check.txt H7715/1.0 server webl 192.168.10.11:80 cookie A weight 78 check server web2 192.168.18.12:88 cookie 8 weight 38 check S main frontend which proxys to the backends 1 192.168.18.15:801 Chuong 5: cAu hinh cai dat va thir nuhiem DO Van Thinh — A13439 listen webfarm 192.168.10.15:80 # Dori thimh clia chi IP cio mode hap stats enable stats auth admin:admin stats uri /haproxy-status stats refresh lOs stats hide-version balance roundrobin cookie JSESSIONID prefix option httpclose option forwardfor option httpchk HEAD /check.txt HTTP/I.0 server webl 192.168.10.11:80 cookie A weight 70 check server web2 192.168.10.12:80 cookie B weight 30 check backend static balance roundrobin server static 192.168.10.10:80 check 64 DO Van Thinh — A13439 thinhdv 7 server: home , thinhdv The Edit yievi Terminal Tags Help * static backend for serving up images, stylesheets and such backend static balance roundrobin server 'static 192.168.10.15:80 check S round robin balancing between the various backends 5.5. Kiem tra & Dinh gii ket qui De kiem tra xem HAProxy co thwc hien can bang tai khong to can co hai trinh duyet web khac nhau nhu Mozilla Firefox vi Google Chrome. Hoac co hai may khitch kat not tai proxy de tranh tinh tang btu cookies. Trwong hpp m(31 Truy cap thong ke /haproxy-status Stati• ics Report for HAPro.y - lgozllla 1 trefox X Ble Ern zee IUatoiy Boolanarks Dols lielp I 0 Statistics Report for HAProxy • 10041:4112.tat1eataiii.....#1.fri I L 192.168.10.15Thaproxy-status S > General process Information pid • 3251 (Pawl nOptx • I) •00 • 00 mane. 22•0111.1ta: inemna• • unkmnd. Simon • 1011 mosaic • WA •owana • a 4,010•• .0 carnal Gonna. 1, carnal pipssat solve UP 11200p UP mom• up yang dawn Stipp UP 0/9 00 wive C00. gc0 lacisp CONN. 030 up mama ONicup C430 na chided o1. R: • /10.2202S2111 • RBIS • =Suss • Use Extental 000,1 • aorta • it= Ni • railin• no t ROMNIIII 1 3 •E a MOM 21111 ED 171 510104 0 0 2 SO WPM web700•01 0 1 • 7 7 3001 10 0 0 0 0 D 10E0 UP 70 • NEON 02 0 • 0 1 0 1 • 3 3 1011 NO nSIMI 0 0 0 0 1000 UP 3) • SE Mc SS 0 0 0 2 0 1 O a 2 M 2 CO O Cl EIENEEME 0 0 33.a... a 2 13 . °"&. ] °I ° °I 1 °I °I° °I I °I 1 l ° 1 °."4"° I 1 I Y I ' l ° I 1 j Truy cap may chit Web ten may may khach ved dia chi 192.168.10.15, kiem tra ck y'eu eau de duce truy xuAt den may chi' 1 va may clui 2 chua. Chuang 5: cau hinh cal dat va thin nghiem 65 E6e Era Von History ir..] Otto //192 168 10 15/ flookmarks gaols Help E 192.168.10.15 6 DO Van Thinh - A13439 Chuang 5: eau birth cai dat vi thir mdulem Manila f veto• x gle Edit glen History goolonarks Dots He I + I • 192.168.10.15 Web Server [1] r elay Web Server [2] Trwong Itcp hai Tren may chit 2, tat dich NT Web # service httpd stop Tren may khach, truy cop 13i (Ha chi may chit Web 192.168.10.15 Manila f irefov gle Edit Vow History goolcmarks gaols yelp I n ittp://192.166.10.15/ • IL; 192.168.10.15 al 6 Web Server [1] 136'ng that kiem tra teen may ad Haproxy Stati:tirs Report for HAPror Ftrefox X 14A V gle Es View History Bookmarks Isola yelp r; Robotics Report for HOProxY it 0 • i 192.168.10.15maproxy • status V to 41 re Statistics Report for pid 16478 > General process information pid • Sae Omni& Pans • A oche up Saco UP DiSplay apear tatr•l to Maas • Od Ihierit231 • nttlf.nta • amismite cam UR going dam Sap UR IMO aim • ato Nails: MINIXIM • ohms& WIMIIII . eon • aslitniogi • Inn contr. aka up Yaw COOL Via up • O sass* • !Da someam • at pla•pIpes •0 stoatior • nag current conns • L apnea paa• OD no a Setup DOWN no chided • a Running tam 314 NOV UP IV. loadaJwarq day! s nand 'Nat k 0 MB OWN 0 0 0 0 0 0 0 0 0 0 la UP ID ID • 1 0 MI UP 1 XIS 1 32 •ISO fl la 1140100 aa0w 0 O 0 O al O a II ad M lain MOOS acrl O 0 O la O 31 IM OD MO lsla 1700) e1a01e 0 66 DI) Van Thinh — A13439 Chucmg 5: cau hinh cal dat va thir nghiem Truing hip ba Tren HAProxy va may chi 1, tit djch vv keepalived # service keepalived stop Truy cap lai may chi Web 192.168.10.15 rionlla F Irigo Elie Edit Mew History ftookmada Dols Help i E.] hdp://192.168.10.15/ Lai Ej 192168.1015 Web Server [2] Qua ket qui tren, chting ta c6 the danh gia mot cach trvc quart khi sir dung bO can bin tai may chi nhu sau: Thu !that la tang kha nail dap img mo rong, de ding them hoac bit may chi mot each de ding nham dap img nhu cau can thiet vii yeu cau cong viec. Trong twang hqp thir nghiem tren, thing ta c6 the them mot so may chit vii cling dii dja chi IP 192.168.10.x hoac gilm bit cac may chi nay di. Thu hai la tang cuing do tin cay, dap img khi flan dg phong, khi mot may chit gap phii sty co thi he thong van dtrqc duy tri hog dOng khong he bj gian down. Thu ba la chin ta ci the de ding theo dei tinh Wang cia cac may chi thong qua giao dien khi mot may chi nio di gap phii sv co. Tiep theo chfing ta se ding danh gia hieu suit cong viec khi sir ding b0 can bang tai trong mo hinh thir nghiep tren vi so sinh yen viec chi sir ding mot may chi hoot dOng cung cap djch Ai Web. Ching ta se sir thing phan mem WAPT la mot cong cv thir nghiem tai cung cap chi phi hieu qui de kiem tra bat Ict dich , vy may chit web nao bao g6m ea ling citing Icinh doanh, cong thong tin web, ... phan mem nay gitip thing ta c6 the tao ra cac bai kiem tra tai trong yang vii phit. Qua trinh kiem tra va danh gia cis chin ta se &Km tien hanh yeti hai truing hqp tren thong qua each thirc sir ding mot Itnyng ngu&i ding that dinh tang tir 1 den 20 ngutii, thing th&i troy cop lay thong tin tren may chi web trong mot khoang thai gian ngan. TrtrOng hqp thir nghiem can bang till vii HAproxy sir dtmg dja chi IP a° 192.168.10.15 cho ta ket qui nhu sau: 67 0.1B 0.16 0.14 0.1.2 0.10 0.08 0.06 0.04 0.02 0.00 20 18 16 14 12 10 8 6 4 2 0:00:00 0:00:20 0:00:40 0:01:00 0:01:20 0:01:40 Active users • Avg response time, sec la Avg 90% response One, sec Chucme 5: eau hinh cal dat vi thin nghiem DO Van Thinh — A13439 Average response time (without page elements) Profile 1.Load Solacing httn•iii ims.tri.ts:ani Tnging hop thin nghieM yea may cher djch vn Web thong during sir dung dia chi 192.168.10.11 cho to ket qua nhu sau: Average response time (without page elements) Profile1.Load Solacing mtnun92.7 6s.in.LI :Rn/ 68 Chuong 5: cau hinh cal dat va this nghiem DO Van Thinh - A13439 Co the nhan xet inns sau: Khi chimg ta tien hanh kiem tra ltru luring tai voi mOt luring ngueri dung Ling dan trong mOt khoang thin gian ngin [that djnh. Doi ydi truing hop sir dong1340 can bang tai thong qua dia chi 192.168.10.15, that gian phitn hoi cac yeu dm se tang din theo so luring ngtricri dung, den ,m0t nguang nick djnh nao d6 khi qua trash tra 161 cac yeu cau girl , den khOng theo kip so luong cac yeu cau, lac nay thai gian phan hoi se lau han do co so tac nghen va can that gian xir 1St. Chimg ta co the thay trutmg hop nay khi chi sir dung mOt may chit cai dat djch vo Web thong qua dja chi )92.168.10.11. Thai gian phim hoi dm may chit nay dot net tang len khi so luring yeu cau tir nguei dimg tang len. 69 DO Van Thjnh - A13439 Ket luan va huong phat thin de tai KET LUAN VA HUY/NG PHAT TRIEN DE TAI Ket luen Can bang tai mang lai Id ich to 16n bang each cai thien tinh sin sang dm he thong may chit, kha nails ma rung quart ljr va an ninh bao mat. Can bang tai may chit la img dung ph6 bien nhat cho bo can bang tai. Ngay nay ding veri sit phat trien vuqt bac cua cong nghe, can bang tai da vi dang phat trien mOt cach manh me de giii quyet cac sv co tat nghen mang va may chit, dem lai giai phap hieu qua nhat cho cac cong ty, doanh nghiep. Bang viec img dung va trien khai cac thiet ke m8 hinh can bang, tai mang tinh sin sang cao, cac cong ty, doanh nghiep cc!) the dap ling dirge Man b0 nhu clu trong cong viec. Thong qua bao cao khaa luan "Tim hieu he thong can bang tai may chit", da co nhung dong gap, ye mat thuyet cling nhu ye mat cong nghe trong viec tim hieu va xay dung cac he thong can bang tai may chit. Sau day la ket qua chinh ma ae tai nay da dirt duqc: • Trinh bay ding quan ve he thong may chit can bang tai. • Gieri thieu cac thuat town *rig dung trong can bang it • Xay dung car thiet ke mpg voi b0 can bang tai. • du hinh cal (tat thin nghiem mo hinh may chit can bang tai, dua ra (lath gia ding quat. Trong pham vi mOt luan van, do han the ve theri gian nghien ciru vi cac yeu t6 khach quan khac, mOt so van de lien quan cna de tai co the vAn clam giii quyet duce mOt each trcm yen, nhung mong rang day la nhung n,Oi dung tim hieu ca ban ,dat nen tang cho sr phat trien nhung nghien sau them ye he thong may chit can bang tai. Hurting phit trien de di NhUng van de duqc de cap trong luan van nay men chi tap trung chit yeu vao nen tang ca ban cita he thong may chit can bang tai va l± thuyet xay dung no. Ngoai ra mo phOng mdi chi dap img phan nho trong trien khai thvc te. Mac du vay, luan van nay cling da dinh hang de phat trien mOt he thong may chit phuc vu Ott cho nhu cau cda cac ding ty vi doanh nghiep. Trong theri gian teri, luan van se di sau vao nhung Ichia canh khac Fla he thong can bang tai dien hinh nhu: can bang tai tren ettremg truyen Internet, can bang it tirtmg lira ... 70 Danh mvc tai lieu tham khao DO Van Thjnh — A13439 DANH MVC TAI LItU THAM MAO 1. Nguyen Truerng Giang. "Tai lieu HAproxy tren CentOS". Giang vien Trung tat' n quan trj mpg PNH. Hit NOi. 2010. 2. Tran Binh. "Cong nghe can bang tat " nghe-can-bing-tai . 2012. 3. Chandra Kopparapu. "Load Balancing Servers, Firewalls, and Caches". Wiley - Canada. 2002. 4. Tony Bourke. "Server Load Balancing". O'Reilly & Associates, Boa K5/. 2001. 5. Yu ShengSheng, Lu Song, Zhou Jingli. "Load Balancing Algorithms". DO hoc khoa hoc va cong nghe. Tnmg Quoc. 2004. 6. John Lewis. "Icy thuat tong quan mgng can bang tin". ibrarv/bb742455 .aspx#X SLTsection124121120 120. 2003. 71