I am using a Python script as a mapper for a Hadoop Streaming (hadoop 0.20.0) job, with reducer NONE. My jobs keep getting killed with "task failed to respond after 600 seconds." I tried sending a heartbeat every minute to stderr using sys.stderr.write in my mapper, but nothing is being output to stderr either on disk (in logs/userlogs/...) or in the web UI. stdout is not even recorded.
This also means I have no way of knowing what my tasks are doing at any given moment except to look at the counts produced in syslog. I got it to work once, but have not had any luck since. Any suggestions of things to look at as to why I am not able to get any output? Help is greatly appreciated. - Ryan
