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1、中國科學(xué)技術(shù)大學(xué)博士學(xué)位論文并行分布計算中的調(diào)度問題研究姓名:孫廣中申請學(xué)位級別:博士專業(yè):計算機軟件與理論指導(dǎo)教師:陳國良;顧鈞20050301中國科學(xué)技術(shù)大學(xué)博士學(xué)位論文(4)類似于sETI@home的大規(guī)模P2P計算系統(tǒng)中的調(diào)度策略研究:提出了相應(yīng)的理論模型來描述其中的任務(wù)調(diào)度問題。在此基礎(chǔ)上,評估現(xiàn)有的幾種不同的調(diào)度策略,設(shè)計了新的根據(jù)具體的網(wǎng)絡(luò)環(huán)境和計算資源進(jìn)行選擇的調(diào)度策略,通過理論分析和實驗分析說明該策略較之現(xiàn)有策略有更好的性能,并將該調(diào)度策略應(yīng)用于實際系統(tǒng)中。本文的主要貢獻(xiàn)和創(chuàng)新有:(1)提出了具有中斷時間代價的~致
2、并行機調(diào)度問題,給出了近似比為常數(shù)的近似算法,證明了問題求解難度和近似難度;(2)研究了多臺機器條件下具有不可用時段的調(diào)度問題,分析了經(jīng)典在線算法的性能并證明了問題的近似難度;(3)針對線性網(wǎng)絡(luò)和環(huán)狀網(wǎng)絡(luò),研究了分布式計算環(huán)境下的任務(wù)調(diào)度模型,證明了問題的難解性,給出了近似性能良好的調(diào)度算法;(4)研究了對等計算環(huán)境下任務(wù)調(diào)度問題,給出了相應(yīng)的調(diào)度模型,針對已有策略的不足設(shè)計了新的策略。關(guān)鍵詞:調(diào)度問題,并行計算,分布式計算,近似算法,F(xiàn)界中國科學(xué)技術(shù)大學(xué)博上學(xué)位論文AbstractSchedulingproblemsareonek
3、indofbasicproblemsincombinationoptimization.Theyarec。ncernedwiththeoptimala110cationofscarceresourcestoactivitiesovertime.Moregenerally,schedulingproblemsinv01vejobsthatf【
4、ustbescheduledonmachinessubjecttocertainconstraintstooptimizesomeobjectivefunction.Fordifferenceo
5、fmachineenvironrnent,sideconstraintsandcharacteristics,optimalityobjects,schedulingproblemscontainthousandsofdifferentschedulingmodels.Manyresearchersindifferentfields,suchasappliedmathernatics,computerscience,managescience:haveachieVedlotsofimportantresultsonschedulin
6、gproblemsinboththeoryandapplication.Inparallelanddistributedcomputing,thereareamassofschedulingproblems.SolVingtheseschedulingproblemshasastrongimpactontheparallelanddistributedcomputingsystems.Toimprovetheperformanceoftheparallelanddistributedsystemseffectively,resear
7、chonthealgorithmsofthoseschedulingproblemsarevaluableintheoryandpractice.Inthispaper,someschedulingproblemsinparallelanddistributedcomputingarestudiedasf0110ws.(1)Apreemptiveschedulingproblemispresented,inwhichanadditionaltimecostisneededifajobisinterruptedonce.Thispap
8、ersh。wsthatproblemisaNP—hardproblem,presentsanoff—lineapproximationalgorithmwithtimecomplexityofO(nlogn+m)andaperformancerationomorethan1.40825.Theon一1inepropertyisalsostudiedandanon一1inealgorithmwithlinearitytimecomplexitYandacompetitiveratioof2isproposed.(2)Weconside
9、rstheon—lineschedulingonidenticalmachineswithmachlneavailabilityconstraintsandanalyzeoftheperformanceoftheLSalgorithm