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Re: How to add debugging to map- red code
here is a sample code from log4j documentation
if you want to specify a specific file where you want to write the log ..
you can have a log4j properties file and add it to the classpath

 import com.foo.Bar;

 // Import log4j classes.
 *import org.apache.log4j.Logger;
 import org.apache.log4j.BasicConfigurator;*

 public class MyApp {

   // Define a static logger variable so that it references the
   // Logger instance named "MyApp".
   *static* Logger logger = *Logger.getLogger(MyApp.class);*

   public static void main(String[] args) {

     // Set up a simple configuration that logs on the console.
     *BasicConfigurator.configure();*

     logger.info("Entering application.");
     Bar bar = new Bar();
     bar.doIt();
     logger.info("Exiting application.");
   }
 }
On Sat, May 5, 2012 at 3:40 AM, Mapred Learn <[EMAIL PROTECTED]> wrote:

> Hi Harsh,
> Could you show one sample of how to do this ?
>
> I have not seen/written  any mapper code where people use log4j logger or
> log4j file to set the log level.
>
> Thanks in advance
> -JJ
>
> On Thu, May 3, 2012 at 4:32 PM, Harsh J <[EMAIL PROTECTED]> wrote:
>
> > Doing (ii) would be an isolated app-level config and wouldn't get
> > affected by the toggling of
> > (i). The feature from (i) is available already in CDH 4.0.0-b2 btw.
> >
> > On Fri, May 4, 2012 at 4:58 AM, Mapred Learn <[EMAIL PROTECTED]>
> > wrote:
> > > Hi Harsh,
> > >
> > > Does doing (ii) mess up with hadoop (i) level ?
> > >
> > > Or does it happen in both the options anyways ?
> > >
> > >
> > > Thanks,
> > > -JJ
> > >
> > > On Fri, Apr 20, 2012 at 8:28 AM, Harsh J <[EMAIL PROTECTED]> wrote:
> > >
> > >> Yes this is possible, and there's two ways to do this.
> > >>
> > >> 1. Use a distro/release that carries the
> > >> https://issues.apache.org/jira/browse/MAPREDUCE-336 fix. This will
> let
> > >> you avoid work (see 2, which is same as your idea)
> > >>
> > >> 2. Configure your implementation's logger object's level in the
> > >> setup/setConf methods of the task, by looking at some conf prop to
> > >> decide the level. This will work just as well - and will also avoid
> > >> changing Hadoop's own Child log levels, unlike the (1) method.
> > >>
> > >> On Fri, Apr 20, 2012 at 8:47 PM, Mapred Learn <[EMAIL PROTECTED]
> >
> > >> wrote:
> > >> > Hi,
> > >> > I m trying to find out best way to add debugging in map- red code.
> > >> > I have System.out.println() statements that I keep on commenting and
> > >> uncommenting so as not to increase stdout size
> > >> >
> > >> > But problem is anytime I need debug, I Hv to re-compile.
> > >> >
> > >> > If there a way, I can define log levels using log4j in map-red code
> > and
> > >> define log level as conf option ?
> > >> >
> > >> > Thanks,
> > >> > JJ
> > >> >
> > >> > Sent from my iPhone
> > >>
> > >>
> > >>
> > >> --
> > >> Harsh J
> > >>
> >
> >
> >
> > --
> > Harsh J
> >
>

--
Nitin Pawar