Hi Kay, Yeah, that line does set your jar as the job jar. "hadoop jar" expects java code to configure and submit your job. "mapred job" takes in a job.xml configuration file and runs the job based on that.
-Sandy On Wed, Mar 13, 2013 at 11:07 AM, KayVajj <vajjalak...@gmail.com> wrote: > Hi Sandy, > > I was going through the RunJar source code and the jar executes locally. > When the jar fires a mapreduce job, > > the way I create JobConf is > > JobConf conf = new JobConf(MyJob.class); >> > > Does this set MyJar as the job jar? > > Can you explain what is the difference between running an MR job using the > jar command vs mapred job command (looks like the hadoop job command is > deprecated). > > Thanks > Kay > > > On Wed, Mar 13, 2013 at 10:14 AM, Sandy Ryza <sandy.r...@cloudera.com>wrote: > >> Hi Kay, >> >> The jar is just executed locally. If the jar fires up a mapreduce job >> and sets itself as the job jar, then mapreduce will handle copying it to >> the nodes that will use it. >> >> -Sandy >> >> >> On Wed, Mar 13, 2013 at 9:01 AM, KayVajj <vajjalak...@gmail.com> wrote: >> >>> I have a question regarding the hadoop jar command. In a cluster of say >>> nodes n1,n2...n100 >>> >>> the node n1 has jar Myjar on its local file system. >>> >>> If I run the command >>> hadoop jar local/path/to/Myjar Myclass other-args >>> >>> Is the MR job executed just on n1 or any arbitrary node n1..n100? >>> >>> If it is any arbitrary node, since Myjar exists only on n1. Is the jar >>> copied across all nodes on the cluster to run the MR code. >>> >>> >>> >>> >>> >> >
