I studying user logs on the two node cluster that I have setup and I was 
wondering if anyone can shed some light on these "attempt*' directories
>$ ls
attempt_201212051224_0021_m_000000_0  attempt_201212051224_0021_m_000003_0  
job-acls.xml
attempt_201212051224_0021_m_000002_0  attempt_201212051224_0021_r_000000_0

I mean its obvious that its talking about 3 attempts for Map task and 1 attempt 
for reduce task. However my current MR job only results in some output written 
to "attempt_201212051224_0021_m_000000_0". Nothing is the reduce part 
(understandably since I don't even have a reducer, so my question is:

1. The two more M attempts. . . what are they?
2. Why was there an attempt to do a Reduce when no reducer was 
provided.implemented
3. Why my master node only had 1 attempt for M task but the slave had all 
that's displayed and questioned above (the 'ls' output above is from the slave 
node)

Thanks
Oleg
 

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