[jira] [Created] (TEZ-1248) Reduce slow-start should special case 1 reducer runs

["Gopal V (JIRA)" <ji...@apache.org>]

Gopal V created TEZ-1248:
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             Summary: Reduce slow-start should special case 1 reducer runs
                 Key: TEZ-1248
                 URL: https://issues.apache.org/jira/browse/TEZ-1248
             Project: Apache Tez
          Issue Type: Improvement
    Affects Versions: 0.5.0
         Environment: 20 node cluster running tez
            Reporter: Gopal V
            Priority: Minor


Reducer slow-start has a performance problem for the small cases where there is just 1 reducer for a case with a single wave.

Tez knows the split count and wave count, being able to determine if the cluster has enough spare capacity to run the reducer earlier for lower latency in a N-mapper -> 1 reducer case.



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