On 0.23 I usually breakpoint on DefaultContainerExecutor.java : 139. Modify the script mentioned in nmPrivateContainerScriptPath to include JAVA remote debugging options. Connect to the nodemanager and then breakpoint again in MRAppMaster.java. Tedious. I know. :(
On Thu, Mar 29, 2012 at 11:06 AM, Ravi Prakash <ravihad...@gmail.com> wrote: > Hi Pedro, > > I know its sub-optimal but you should be able to put in as many > System.out.println / log messages as you want and you should be able to see > them in stdout, and syslog files. Which version of hadoop are you using? > > > > > On Thu, Mar 29, 2012 at 10:33 AM, Pedro Costa <psdc1...@gmail.com> wrote: > >> Hi, >> >> I'm trying to debug map and reduce tasks for a quite long time, and it >> seems that it's impossible. MR are launched in new process and there's no >> way to debug them. Even with IsolationRunner class it's impossible. This >> isn't good because I really need to debug the class, to understand some >> changes that I made to the code. >> >> I wonder how MapReduce programmers could debug the code that they >> implemented? >> >> -- >> Best regards, >> >> >
