Hi, You could also use apache commons logging to write logs in your map/reduce functions which will be seen in the jobtracker UI. that's how we did debugging :)
Hope it helps Regards, Raakhi On Tue, Jun 16, 2009 at 7:29 PM, jason hadoop <jason.had...@gmail.com>wrote: > When you are running in local mode you have 2 basic choices if you want to > interact with a debugger. > You can launch from within eclipse or other IDE, or you can setup a java > debugger transport as part of the mapred.child.java.opts variable, and > attach to the running jvm. > By far the simplest is loading via eclipse. > > Your other alternative is to inform the framework to retain the job files > via keep.failed.task.files (be careful here you will fill your disk with > old > dead data) and use the debug the IsolationRunner > > Examples in my book :) > > > On Mon, Jun 15, 2009 at 6:49 PM, bharath vissapragada < > bharathvissapragada1...@gmail.com> wrote: > > > I am running in a local mode . Can you tell me how to set those > breakpoints > > or how to access those files so that i can debug the program. > > > > The program is generating => java.lang.NumberFormatException: For input > > string: "" > > > > But that particular string is the one which is the input to the mapclass > . > > So I think that it is not reading my input correctly .. But when i try to > > print the same .. it isn't printing to the STDOUT .. > > Iam using the FileInputFormat class > > > > FileInputFormat.addInputPath(conf, new > > Path("/home/rip/Desktop/hadoop-0.18.3/input")); > > FileOutputFormat.setOutputPath(conf, new > > Path("/home/rip/Desktop/hadoop-0.18.3/output")); > > > > input and output are folders for inp and outpt. > > > > It is generating these warnings also > > > > 09/06/16 12:38:32 WARN fs.FileSystem: "local" is a deprecated filesystem > > name. Use "file:///" instead. > > > > Thanks in advance > > > > > > On Tue, Jun 16, 2009 at 3:50 AM, Aaron Kimball <aa...@cloudera.com> > wrote: > > > > > On Mon, Jun 15, 2009 at 10:01 AM, bharath vissapragada < > > > bhara...@students.iiit.ac.in> wrote: > > > > > > > Hi all , > > > > > > > > When running hadoop in local mode .. can we use "print" statements to > > > print > > > > something to the terminal ... > > > > > > > > > Yes. In distributed mode, each task will write its stdout/stderr to > files > > > which you can access through the web-based interface. > > > > > > > > > > > > > > Also iam not sure whether the program is reading my input files ... > If > > i > > > > keep print statements it isn't displaying any .. can anyone tell me > how > > > to > > > > solve this problem. > > > > > > > > > Is it generating exceptions? Are the files present? If you're running > in > > > local mode, you can use a debugger; set a breakpoint in your map() > method > > > and see if it gets there. How are you configuring the input files for > > your > > > job? > > > > > > > > > > > > > > > > > > Thanks in adance, > > > > > > > > > > > > > -- > Pro Hadoop, a book to guide you from beginner to hadoop mastery, > http://www.amazon.com/dp/1430219424?tag=jewlerymall > www.prohadoopbook.com a community for Hadoop Professionals >