Karim: If you want to debug unit tests, using Eclipse is a viable approach. Here is what I did the past week debugging certain part of hadoop (JobSubmitter in particular) through an HBase unit test.
Run 'mvn install -DskipTests' to install hadoop locally Open the class you want to debug and place breakpoint at proper location Open unit test which depends on the class above and select Debug As -> JUnit Test When breakpoint hits, associate the sources.jar file in local maven repo with the class. In my case, the sources jar file is located under ~/.m2/repository/org/apache/hadoop/hadoop-mapreduce-client-core/2.1.2-SNAPSHOT You should be able to step through hadoop code as usual at this point. Cheers On Sun, Oct 6, 2013 at 6:14 AM, John Lilley <[email protected]>wrote: > Karim,**** > > ** ** > > I am not an experienced Hadoop programmer, but what I found was that > building and debugging Hadoop under Eclipse was very difficult, and I was > never to make it work correctly. I suggest using the well documented > command-line Maven build, installing Hadoop from that build, and running it > normally. Once you have that working, run your namemode or datanode daemon > so as to wait for a remote debugger attach before starting. You should > also get comfortable with log4j, the logging framework used by Hadoop, as > those log files are often your best friend when trying to debug a > collection of services.**** > > ** ** > > john**** > > ** ** > > *From:* Karim Awara [mailto:[email protected]] > *Sent:* Sunday, October 06, 2013 5:41 AM > *To:* user > *Subject:* Hadoop 2.x with Eclipse**** > > ** ** > > Hi, **** > > I followed the instructions on how to import hadoop files to Eclipse (I am > using hadoop 2.1 beta). **** > > Currently on my machine, I have hadoop 2.1 installed.. and its source code > is imported on Eclipse. What I can't grasp is how to proceed from there? > **** > > I want to modify HDFS code (blockplacement strategy).. Now building hdfs > project via generates errors to me (unresolved types in hadoop common). > and if i built successfully, how to test my modified code?**** > > > **** > > -- > Best Regards, > Karim Ahmed Awara**** > > ** ** > ------------------------------ > > This message and its contents, including attachments are intended solely > for the original recipient. If you are not the intended recipient or have > received this message in error, please notify me immediately and delete > this message from your computer system. Any unauthorized use or > distribution is prohibited. Please consider the environment before printing > this email.**** >
