英文面試問題及答案參考

英文面試問題及答案參考

1、Whatisloadtesting?-Loadtestingistotestthat

iftheapplicationworksfinewiththeloadsthatresult

fromlargenumberofsimultaneoususers,transactionsand

todetermineweatheritcanhandlepeakusageperiods.

2、WhatisPerformancetesting?-Timingforbothread

andtransactionsshouldbegatheredtodeterminewhether

systemfunctionsarebeingperformedinanaeptable

timeframe.Thisshouldbedonestandaloneandthenina

multiuserenvironmenttodeterminetheeffectofmultiple

transactionsonthetimingofasingletransaction.

3、DiduuseLoadRunner?Whatversion?-Yes.Version

7.2.

4、ExplaintheLoadtestingprocess?-

Step1:Planningthetest.Here,wedevelopaclearly

definedtestplantoensurethetestscenarioswedevelop

willaomplishload-testingobjectives.Step2:Creating

Vusers.Here,wecreateVuserscriptsthatcontaintasks

performedbyeachVuser,tasksperformedbyVusersasa

whole,andtasksmeasuredastransactions.Step3:Creating

thescenario.Ascenariodescribestheeventsthatour

duringatestingsession.Itincludesalistofmachines,

scripts,andVusersthatrunduringthescenario.Wecreate

scenariosusingLoadRunnerController.Wecancreatemanual

scenariosaswellasgoal-orientedscenarios.Inmanual

scenarios,wedefinethenumberofVusers,theload

generatormachines,andpercentageofVuserstobeassigned

toeachscript.Forwebtests,wemaycreateagoal-

orientedscenariowherewedefinethegoalthatourtest

hastoachieve.LoadRunnerautomaticallybuildsascenario

forus.Step4:Runningthescenario.

Weemulateloadontheserverbyinstructingmultiple

Vuserstoperformtaskssimultaneously.Beforethetesting,

wesetthescenarioconfigurationandscheduling.Wecan

runtheentirescenario,Vusergroups,orindividualVusers.

Step5:Monitoringthescenario.

WemonitorscenarioexecutionusingtheLoadRunner

onlineruntime,transaction,systemresource,Webresource,

Webserverresource,Webapplicationserverresource,

databaseserverresource,workdelay,streamingmedia

resource,firewallserverresource,ERPserverresource,

andJavaperformancemonitors.Step6:Analyzingtest

results.Duringscenarioexecution,LoadRunnerrecordsthe

performanceoftheapplicationunderdifferentloads.We

useLoadRunner’sgraphsandreportstoanalyzethe

application’sperformance.

5、WhendoyoudoloadandperformanceTesting?-We

performloadtestingoncewearedonewithinterface(GUI)

testing.Modernsystemarchitecturesarelargeandplex.

Whereassingleusertestingprimarilyonfunctionalityand

userinterfaceofasystemponent,applicationtesting

focusesonperformanceandreliabilityofanentiresystem.

Forexample,atypicalapplication-testingscenariomight

depict1000userslogginginsimultaneouslytoasystem.

Thisgivesrisetoissuessuchaswhatistheresponsetime

ofthesystem,doesitcrash,willitgowithdifferent

softwareapplicationsandplatforms,canitholdsomany

hundredsandthousandsofusers,etc.Thisiswhenweset

doloadandperformancetesting.

6、WhataretheponentsofLoadRunner?-Theponentsof

LoadRunnerareTheVirtualUserGenerator,Controller,and

theAgentprocess,LoadRunnerAnalysisandMonitoring,

LoadRunnerBooksOnline.

7、WhatComponentofLoadRunnerwouldyouusetorecord

aScript?-TheVirtualUserGenerator(VuGen)ponentis

usedtorecordascript.ItenablesyoutodevelopVuser

scriptsforavarietyofapplicationtypesandmunication

protocols.

8、WhatComponentofLoadRunnerwouldyouusetoplay

Backthescriptinmultiusermode?-TheControllerponent

isusedtoplaybackthescriptinmulti-usermode.Thisis

doneduringascenariorunwhereavuserscriptisexecuted

byanumberofvusersinagroup.

9、Whatisarendezvouspoint?-Yourendezvouspoints

intoVuserscriptstoemulateheavyuserloadontheserver.

RendezvouspointsinstructVuserstowaitduringtest

executionformultipleVuserstoarriveatacertainpoint,

inorderthattheymaysimultaneouslyperformatask.For

example,toemulatepeakloadonthebankserver,youcana

rendezvouspointinstructing100Vuserstodepositcash

intotheiraountsatthesametime.

10、Whatisascenario?-Ascenariodefinestheevents

thatourduringeachtestingsession.Forexample,a

scenariodefinesandcontrolsthenumberofusersto

emulate,theactionstobeperformed,andthemachineson

whichthevirtualusersruntheiremulations.

11、ExplaintherecordingmodeforwebVuserscript?-

WeuseVuGentodevelopaVuserscriptbyrecordingauser

performingtypicalbusinessprocessesonaclient

application.VuGencreatesthescriptbyrecordingthe

activitybetweentheclientandtheserver.Forexample,in

webbasedapplications,VuGenmonitorstheclientendof

thedatabaseandtracesalltherequestssentto,and

receivedfrom,thedatabaseserver.WeuseVuGento:

Monitorthemunicationbetweentheapplicationandthe

server;Generatetherequiredfunctioncalls;andInsert

thegeneratedfunctioncallsintoaVuserscript.

12、Whydoyoucreateparameters?-Parametersarelike

scriptvariables.Theyareusedtovaryinputtotheserver

andtoemulaterealusers.Differentsetsofdataaresent

totheservereachtimethescriptisrun.Bettersimulate

theusagemodelformoreauratetestingfromtheController;

onescriptcanemulatemanydifferentusersonthesystem.

13、Whatiscorrelation?Explainthedifferencebetween

automaticcorrelationandmanualcorrelation?-Correlation

isusedtoobtaindatawhichareuniqueforeachrunofthe

scriptandwhicharegeneratedbynestedqueries.

Correlationprovidesthevaluetoavoiderrorsarisingout

ofduplicatevaluesandalsooptimizingthecode(toavoid

nestedqueries).Automaticcorrelationiswherewesetsome

rulesforcorrelation.Itcanbeapplicationserver

specific.Herevaluesarereplacedbydatawhichare

createdbytheserules.Inmanualcorrelation,thevaluewe

wanttocorrelateisscannedandcreatecorrelationisused

tocorrelate.

14、Howdoyoufindoutwherecorrelationis

required?Givefewexamplesfromyourprojects?-Twoways:

Firstwecanscanforcorrelations,andseethelistof

valueswhichcanbecorrelated.Fromthiswecanpicka

valuetobecorrelated.Secondly,wecanrecordtwoscripts

andparethem.Wecanlookupthedifferencefiletosee

forthevalueswhichneededtobecorrelated.Inmyproject,

therewasauniqueiddevelopedforeachcustomer,itwas

nothingbutInsuranceNumber,itwasgenerated

automaticallyanditwassequentialandthisvaluewas

unique.I