Hello everyone, I am currently working on a research project where i need to understand the yarn mapreduce Application Master code in hadoop 2.7.3. I have downloaded hadoop-2.7.3 source code, built it, I have a local Hadoop configuration on my machine. I can successfully run wordcount application in my hadoop setup using intelliJ IDE.
However, I can not attach Intellij debugger to a running process to debug Application Master code. I can debug the wordcount application source code but I have trouble attaching the the application master (MRAppMaster.java). I tried to follow suggestions that I found on the web about setting HADOOP_OPTS and/or JAVA_OPTS to something like export JAVA_OPTS="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005" but I ran into problems, since the same port can only be used once. Hadoop starts however multiple jvms, and by setting these options generally all jvm try to bind to that port. Does anybody have experience on how to specifically attach to the mapreduce application master ? Thanks in advance Tanvir
