Running the CDH 5.3.0 Quickstart VM; submitted a MR job and it was just sitting in YARN with no indication of progress.

http://quickstart.cloudera:8088/cluster/

Cloudera Manager shows lots of systems with log out of space errors so I looked through the filesystem for where I could free up space; found what appears to be excessive usage in the YARN usercache folder (6 GB in use).

File location is:

/yarn/nm/usercache/[user]/filecache

Can I just delete the cache manually or is there a better way?  Is there a way to configure YARN to use less space?