jobtracker UI doesn't load

[dwyerk]

When I install a new hadoop cluster using cdh4.5.0 MR1, the jobtracker UI won't load out of the box. Instead, when I point my browser to master:50030 I see a directory listing.

If I copy /usr/lib/hadoop/share/hadoop/mapreduce/webapps to /usr/lib/hadoop and restart the jobtracker, the UI works. I tried making that a symlink, but jetty is not willing to follow the symlink for static files.

I think the solution is probably to adjust the classpath somehow but it's not immediately clear to me what the best way to do that is.

[sroegner]

Sorry for that - frankly i never tried cdh mr1. Will take a look.

[sroegner]

Just as an update: i tried a couple of different distributions and hadoop versions and wasn't once able to get past the error message. I was also unable to identify any explicit configuration to make this work so maybe some other piece is just not in the right place yet. But right now I am at a loss as to what that might be.

[dwyerk]

I did a lot of googling for the solution as well and I can find people with the same problem but rarely a solution to go along with them. I did discover the workaround (copying webapps to /usr/lib/hadoop) on one of these threads, but it isn't a very satisfying solution.

My thought about the classpath is based on that workaround: I think that /usr/lib/hadoop is in the classpath but maybe /usr/lib/hadoop/share/hadoop/mapreduce/ is not?

Thanks for trying to run this down.

[sroegner]

Same here. The hadoop env script in HADOOP_HOME/bin looks for a webapps directory in HADOOP_HOME and if it finds that adds HADOOP_HOME itself to the CLASSPATH. I tried just adding the path containing the webapps as HADOOP_CLASSPATH to no avail. I think we're getting close but this is pretty tedious.