我正在尝试退出在Dataproc上运行的映射器作业。遵循建议here，我简单地定义了一个log4j记录器并向它提供了信息:importorg.apache.log4j.Logger;publicclassSampleMapperextendsMapper{privateLoggerlogger=Logger.getLogger(SampleMapper.class);@Overrideprotectedvoidsetup(Contextcontext){logger.info("InitializingNoSQLConnection.")try{//logicforconnecting

我在HIVEshell中执行一个查询SELECTtradeId,bookid,foidfromtradeswherebookid='"ABCDEFG"'"trades"表在bookid上有索引。当查询运行时，它显示Mappers和Reducers的详细信息如下:-Numberofreducetasksissetto0sincethere'snoreduceoperatorHadoopjobinformationforStage-1:numberofmappers:48;numberofreducers:0Timetaken:**606.183seconds**,Fetched:**18

我正在使用here中的示例作为MATLAB2014b中的“使用MapReduce计算平均值”。当我运行示例时，出现以下错误:Startingparallelpool(parpool)usingthe'local'profile...Errorusingmapreducer(line96)Failedtostartaparallelpool.(Forinformationinadditiontothecausingerror,validatetheprofile'local'intheClusterProfileManager.)Erroringcmr(line34)mr=mapredu