简介:Asatypicalerasurecodingchoice,Reed-Solomon(RS)codeshavesuchhighrepaircostthatthereisapenaltyforhighreliabilityandstorageefficiency,therebytheyarenotsuitableingeo-distributedstoragesystems.Wepresentanovelfamilyofconcurrentregenerationcodeswithlocalreconstruction(CRL)inthispaper.TheCRLcodesenjoythreebenefits.Firstly,theyareabletominimizethenetworkbandwidthfornoderepair.Secondly,theycanreducethenumberofaccessednodesbycalculatingparitiesfromasubsetofdatachunksandusinganimpliedparitychunk.Thirdly,theyarefasterthanexistingerasurecodesforreconstructioningeo-distributedstoragesystems.Inaddition,wedemonstratehowtheCRLcodesovercomethelimitationsoftheReed-Solomoncodes.Wealsoillustrateanalyticallythattheyareexcellentinthetrade-offbetweenchunklocalityandminimumdistance.Furthermore,wepresenttheoreticalanalysisincludinglatencyanalysisandreliabilityanalysisfortheCRLcodes.Byusingquantitycomparisons,weprovethatCRL(6,2,2)isonly0.657xofAzureLRC(6,2,2),wheretherearesixdatachunks,twoglobalparities,andtwolocalparities,andCRL(10,4,2)isonly0.656xofHDFS-Xorbas(10,4,2),wherethereare10datachunks,fourlocalparities,andtwoglobalparitiesrespectively,intermsofdatareconstructiontimes.OurexperimentalresultsshowtheperformanceofCRLbyconductingperformanceevaluationsinbothtwokindsofenvironments:1)itisatleast57.25%and66.85%morethanitscompetitorsintermsofencodinganddecodingthroughputsinmemory,and2)ithasatleast1.46xand1.21xhigherencodinganddecodingthroughputsthanitscompetitorsinJBOD(JustaBunchOfDisks).WealsoillustratethatCRLis28.79%and30.19%morethanLRConencodinganddecodingthroughputsinageo-distributedenvironment.