#getConf
所有的配置都通过命令的形式,此种情况下支持-filessudo -uwirelessdev hadoop jar \/home/q/script/mods/mrjob/mods-1.0-SNAPSHOT-jar-with-dependencies.jar \-files /home/q/script/mods/mrjob/mods.acid \-D mapreduce.job.queuename=wirelessdev \-D mapreduce.job.priority=VERY_HIGH \-D mapreduce.map.memory.mb=8192 \-D mapreduce.map.java.opts='-Xmx8192M' \-D mapreduce.reduce.memory.mb=8192 \-D mapreduce.reduce.java.opts='-Xmx8192M' \-D mapreduce.job.reduces=100 \-D mapred.reduce.tasks=100 \-D mapreduce.job.name=mods_firstjob_leofei.li \/user/wirelessdev/marmot_warehouse/ods/ods_modss_frame/dt=2016-07-13/platform=Ios-pad/* \/user/wirelessdev/leofei.li/firstjob
#new Configuration 配置项通过代码进行配置，此时，通过命令行的配置项会失效
Configuration conf =new Configuration();conf.set("fs.defaultFS","hdfs://qunarcluster");conf.set("mapreduce.job.queuename","wirelessdev");conf.set("mapreduce.job.reduces","100");conf.set("mapreduce.job.priority","VERY_HIGH");conf.set("mapreduce.map.memory.mb","8192");conf.set("mapreduce.map.java.opts","-Xmx8192M");conf.set("mapreduce.reduce.memory.mb","8192");conf.set("mapreduce.reduce.java.opts","-Xmx8192M"); 该情况下不支持-files，需要使用DistributedCache,默认hdfs路径
DistributedCache.addCacheFile(new Path("/user/wirelessdev/leofei.li/conf/mods.acid").toUri(), conf); #推荐
Configuration conf = getConf(); conf.set("mapreduce.job.queuename","wirelessdev");Job job = Job.getInstance(conf,"mods_firstjob_leofei.li");