)一种新的分布式Web服务器负载平衡算法

FESWeb1FESWeb:WebWebWebWebWeb(2k)(FES)FESWeb2..................................................................................31.1Web.........................................31.2Web...............................4FES..........................................................62.1FES..................................................62.2FES...............6..................................................................................9................................................................................9..............................................................................22..............................................................................24..............................................................................25................................................................................274.1...............................................................................27..............................................................................274.3...............................................................................28..............................................................................................29..............................................................................................31..............................................................................................32Abstract................................................................................................33FESWeb31.1WebInternetWebWebWeb1WebWebFESWeb4Web1.2Web[1]WebOsloXmitbyteTCPWeb[1]IowaFESWeb5FESWeb62.1FES1(FES)c2.2FESWeb2FESWeb72RRLCFFESPnbjrjrj=bjj1(RR)Pj=||}|{||1kkbrk?FESWeb8(1)2(LCF)j||}),....,,min(|{||121kkmkbrrrrrk??jsjrjTj=lj+rj/sjj||}),....,,min(|{||121kkmkbrTTTTk??FESWeb9(1)WebWeb(RR)(LCF)(FES)Jamming.Net[13]FESJamming.NetJavaTCP/IPHttpSolaris,WindowsNTLinuxJamming.NetJavaHttpScheduleWebApacheVc++HttpServerWebWindows2000DELLApache1.3Httpserver1.0Windwos2000Apache1.3HttpSchedulejdk1.1.8(RR)(LCF)(FES)FreeBsdUnixSclient[12]MUD(Multi-Users-Dimensions)GET2HttpScheduleHttpServera)HttpScheduleFESWeb10BalancePolicy.javaFESWeb11FESWeb12FESWeb13+1(+*)FESWeb14FESWeb15FESWeb16FESWeb17FESWeb18FESWeb19FESWeb20FESWeb21GETFESWeb22110MHub2345HubPing0.3—0.62DELLApache1.3Httpserver1.0index.html150Httpserver1.0Sleep1Httpserver1.055Httpserver1.0FESWeb233java4ms-dosJavac*.javaJavaHttpSchedule66HttpSchedule5DELLHttpScheduleGUIIPFreeBsdSclientSclient.cIp1616(HttpSchedule)6HttpScheduleHttpScheduleGUI7FESWeb247HttpScheduleroundrobin(RR)leastconnfirst(LCF)firstendserv(FES)7WebSclientSclient.c,”index.html”8index.html2k956Sclient10WebSclientCPUHttp1120—30Sclient15022kFESWeb253Mb/scycle/s(us)DELL0.381163.42881660.27834.11763148RR0.430154.2167090LCF0.407140.5229235FES0.417150.11903802150Mb/scycle/s(us)DELL0.460104.53505050.56033.41796581RR0.455149.6322498LCF0.495146.4233743FES0.405139.420983032kWeb150FESRRLCFRRFESLCFRR(2k)FESWeb26/FESLCFFESLCFRRWebFESWeb274.1Web(FES)Web(RR)(LCF)(FES)(2k)FESLCFRR150FESRRWebFESWeb284.3FESWebWebWebFESWeb29FESWeb30FESWeb31FESWeb32WebInternetWebWebWebRRLCFFESFESFESLCFRRFESLCFRRApacheHttpServerWebFESWebWeb150FES(2k)FESWebFESWeb33WebisanInternet-basedhypertextdistributedinformationsystem.Inthisinformationage,Webtechniqueshavebeenveryimportantforpeopletointercommunicate.ThedistributedWebserverhasbeenanindispensabilitytoolforitslowpriceandhighperformance.TherehavebeenmanyloadbalancingalgorithmsforadistributedWebserverbynow,suchasround-robin(RR)andleast-connection-first(LCF)etc.Inthispaper,Ipresentedadynamicload-balancingalgorithm,fist-ended-service(FES).FESchoosesabackserver,whoselatency+request/capacityisthelowest,astheservingnode.Infact,therealizationofFESisharderthanRRandLCF,butitsloadbalancingperformanceisbetterthantheothertwoalgorithms.Ihadtestedthesystemperformanceunderdifferentloadbalancingalgorithmswithanexperiment.TheschedulerisJamming.Netwithaddingotherfunctions.TwobackserversrundifferentWebserversoftware.OneisApacheandtheotherisHttpServerprogrammedbymyself.Bythisway,IcanbettersimulateadistributedWebserverwithdifferentbackservercapacity.IwrotetheschedulerandserverprogramswithabovesoftwareandrealizedFES.Ontheclient,IpartlytestedtheperformanceofeachbackserveranddistributedWebserverunderthedifferentloadbalancingalgorithms.Withthetestingresults,IfoundmanyfactorsthatcouldinfluencetheWebservercapacity.Eventhoughunderthesameloadbalancingalgorithm,theservingcapacitymaychangewithvarietyservicefiles.Whiletheclientrequestsareshorter(averagebeing150bytes),theperformanceunderFESislowerthanRRandhigherthanLCF.Whiletheclientrequestsarelonger(averagebeing2kbytes),theperformanceunderFESishighest.Thisload-balancingalgorithmfitsforthedistributedWebserverwithdifferentbackservercapacityandisbettersuitableforservingstaticservicefilesandbigservicefiles.