It actually does work. See the task attempt log for that job in the web browser for an easy solution. Or tail -f the appropriate log file.
URL for task log is something like -- http://site:50060/tasklog?taskid={{ attempt_id }}&all=true and is navigable to, from the JT. The stdout is also written to the tasktracker's log directory, under $HADOOP_HOME/logs/userlogs/{{ attempt_id }}/stdout, which is what the above url also serves, if am right. Although yes, stdout from mappers or reducers will not appear in your launcher/driver program's output (i.e. hadoop jar [...]). On Fri, Oct 22, 2010 at 2:44 PM, Flavio Pace <[email protected]> wrote: > > Hi, > > This is the first time that i use Map-Reduce with Hadoop.. I need to print > some information in Reduce function to se if my code it's correct , but when > i run System.out.println() there is not output in my log. > > Someone can explain how to print debug information from reduce function to my > log stdout? > > thanks > > Flavio > > > > -- Harsh J www.harshj.com
