Hadoop - 如何使用和减少多个输入？

Question

Mapper/Reducer 1 --> (key,value)
                      /   |   \
                     /    |    \
     Mapper/Reducer 2     |    Mapper/Reducer 4
     -> (oKey,oValue)     |    -> (xKey, xValue)
                          |
                          |
                    Mapper/Reducer 3
                    -> (aKey, aValue)

我有一个日志文件,我与MR1聚合.Mapper2,Mapper3,Mapper4将MR1的输出作为输入.乔布斯被束缚住了.

MR1输出:

User     {infos of user:[{data here},{more data},{etc}]}
..

MR2输出:

timestamp       idCount
..

MR3输出:

timestamp        loginCount
..

MR4输出:

timestamp        someCount
..

我想结合MR2-4的输出:最终输出 - >

timestamp     idCount     loginCount   someCount
..
..
..

没有猪或蜂巢的方式吗？我正在使用Java.

Answer 1

您可以使用MultipleInputs来做到这一点，请参阅此处的示例