Hi, I've suggested and created a patch for node-level aggregation(MAPREDUCE-4502). This patch is now ready for review by anyone. The design doc is also available for review at JIRA[1].
Aggregation jobs with Hadoop are very common, so this work can achieve better experience with Hadoop. [1] https://issues.apache.org/jira/secure/attachment/12579117/design_v3.pdf Thanks, - Tsuyoshi
