电子商务网站英文论文3

电子商务网站英文论文

OptimalDesignofE-CommerceSiteInfrastructure

fromaBusinessPerspective

JacquesSauv´e ,FilipeMarques ,Ant aoMoura ,MarcusSampaio ,Jo aoJornada andEduardoRadziuk

FederaldeCampinaGrande,Brazil

Email:{jacques, lipetm,antao,sampaio}@dsc.ufcg.edu.br

Hewlett-Packard-Brazil

Email:{joao.jornada,eduardo.radziuk}@hp.com

Abstract—Amethodologyfordesigningdatacenterinfrastruc-tureforE-commercesitesisdeveloped.Itdiffersfromexistingmethodologiesinthatitevaluatesandcomparesalternativedesignsfromabusinessperspective,thatis,byevaluatingthebusinessimpact( nancialloss)imposedbyimperfectinfras-tructure.Themethodologyprovidestheoptimalinfrastructurethatminimizesthesumofprovisioningcostsandbusinesslossesincurredduringfailuresandperformancedegradations.Afullnumericalexampledesignisprovidedandresultsareanalyzed.Theuseofthemethodfordynamicallyprovisioninganadaptiveinfrastructureisbrie ydiscussed.

Universidade

I.INTRODUCTION

TheproblemaddressedinthispaperisthatofinfrastructuredesignforInformationTechnology(IT)servicesthatcatertobusinessprocessesthatareheavilydependentonIT.Anexampleofsuchabusinessprocessisthatsupportedbyane-commercesite:ITservicesarethemaintechnologysupportinsuchacontextandanyfailureorperformancedegradationintheITinfrastructurecanprofoundlyaffectbusinessoperations.WithinthegeneralproblemofdesigninginfrastructuretoprovisionITservices,theworkreportedhereconcentratesonthedatacenter,thatpartoftheinfrastructuremosteasilycontrollablebytheserviceprovider.Currentapproachesindatacenterdesignusuallyeitherconsidertheproblemfromareliabilitypointofview,e.g.[1],fromaresponsetimepointofview,e.g.[2]or,morerecently,fromabusinessperspective,e.g.[3].Thelastapproachismorenovelandmeritssomediscussion.

Anewareaofacademicresearch–andalsooftheprac-titioner’sart–istermedBusiness-DrivenITManagement(BDIM)[4],[5],[6].BDIMtakesServiceManagement(SM)toanewmaturitylevelsincemetricsmeaningfultothecus-tomerareusedtogaugeITeffectivenessratherthantechnicalmetricssuchasavailabilityandresponsetime.Thisisthecrucialdeparturethatthepresentworktakesonmostpastefforts.

Inthepresentstudy,infrastructuredesignaimstodecidehowmanyandwhatkindofresourcecomponentsshouldbeusedtoprovisionITservices.Clearly,addingmorefail-overserverswillimproveserviceavailabilityandaddingmoreload-balancedserverswilllowerresponsetime.Butwhatvaluesofavailabilityorofresponsetimeshouldthedesigneraimfor?Howdoesonecombinerequirementsonavailabilityandrequirementsonresponsetimeintocoherentdesigndecisions?

BDIManswersthisquestionasfollows:theimpactofanyITinfrastructureimperfectionshouldbegaugedintermsofitsimpactonbusinessascapturedbybusinessmetrics.Thedesigndecisionsshouldthenbeevaluatedintermsofthebusinessimpactcausedbytheresultingdesign.

ThispaperprovidesaconcretebusinessimpactmodelthatincludestheimpactofITcomponentfailuresonserviceavailabilityand,inturn,onthebusinessandtheimpactofloadonperformance(responsetime)and,inturn,onthebusiness.Usingthisimpactmodel,theproblemofdesigningoptimizedITinfrastructureisformallyde nedandsolvedanalytically.Therestofthepaperisstructuredasfollows:sectionIIinformallydiscussesthedesignproblemusingaBDIMap-proachwhilesectionIIIformalizesit;sectionIVconsidersanapplicationofthemethodthroughafullnumericalexample;sectionVdiscussesrelatedwork;conclusionsareprovidedinsectionVI.

II.INFORMALPROBLEMDESCRIPTION

Infrastructuremustbedesignedforane-commercesite.Theapproachtakenwas rstsuggestedin[6]andaimstominimizemonthly nancialoutlaysascalculatedbytheinfrastructurecostplusthebusinesslossincurredduetotheimperfectinfrastructure.Thus,theapproachusesabusinessperspectiveinthedesignprocessthroughabusinessimpactmodel.TwokindsofimperfectionspresentintheITinfrastructureareconsidered,bothgeneratingbusinessloss.The rstisthatcomponentsmayfail,renderingtheserviceunavailablepartofthetime.Thesecondisthattheloadimposedontheinfrastructurecomponentsresultsindelays,withthepossibilityofcustomersdefectingduetooverlargedelays.

Sessionsvisitingthesitearedividedintotwotypes:revenue-generatingsessionswhere,atsomepointduringthevisit,somerevenuewillaccruetothesite’sowner;inthesecondtypeofsession,customersmayvisitpagesonthesite,maypossiblyevenbeaddingitemstoashoppingcart,butendupdesistingbeforegeneratingrevenue.

Theinfrastructureitselfconsistsofseveraltiers,sayawebtier,anapplicationtierandadatatier.Eachtierisservedbyaload-balancedclusterwithacertainnumberofmachines,suf cienttohandletheappliedload.Varyingthisnumberofmachinesaffectsresponsetimeandthusthebusinesslossduetocustomerdefections.Furthermore,additionalmachinesare