Re: Does the map task push map output to reduce task or reduce task pull it from map task

[dave bayer]

On Oct 26, 2009, at 6:05 PM, Jeff Zhang wrote:
I'd like to know does the map task push map output to reduce task or  
reduce
task pull it from map task ? Which way is real in hadoop ?

In 0.19, it appears to be a pull. Look at the run() method in mapred/ 
org/apache/hadoop/mapred/ReduceTask.java. Don't
know what the equivalent would be in the mapreduce package
in 0.20.x.

dave bayer