Hey Richard,
I'm interested in the same thing myself :D. I was researching it
earlier today, and the best I know to do is to use Eclipse's remote
debugging functionality (although this won't completely work. each map/
reduce task spawns on its on JVM, making debugging really hard). but
if you want, you can debug up until the mappers/reducers spawn. To do
this, you need to pass certain debug-flags into the JVM. So you'd need
to do export HADOOP_OPTS=myFLagsForRemoteDebug
and then you'd go to eclips ->run->open debug dialog and set up remote
debugging with the correct port.
if you find out a way to debug the mappers/reducers on eclipse, let me
know :D
On Jun 16, 2008, at 3:10 PM, Richard Zhang wrote:
Hello Hadoopers:
Is there a way to debug the hadoop code from Eclipse IDE? I am
using Eclipse to read the source and build the project now.
How to start the hadoop jobs from Eclipse? Say if we can put the
server names, could we trace the running process through
eclipse, such as setting breakpoints, check the variable values?
That should be very helpful for development.
If anyone know how to do it, could you please give some info?
Thanks.
Richard
