0
我創建了一個ShuffleConsumerPlugin
自定義實現,它的工作原理。但是,在我的映射任務完成後,它被實例化:爲什麼ShuffleConsumerPlugin在映射之前未啓動?
org.apache.hadoop.mapred.LocalJobRunner: Waiting for map tasks
org.apache.hadoop.mapred.LocalJobRunner: Starting task: attempt_local1582630093_0001_m_000000_0
org.apache.hadoop.mapred.LocalJobRunner: map > sort
org.apache.hadoop.mapred.Task: Task 'attempt_local1582630093_0001_m_000000_0' done.
org.apache.hadoop.mapred.LocalJobRunner: map task executor complete.
org.apache.hadoop.mapred.LocalJobRunner: Waiting for reduce tasks
org.apache.hadoop.mapred.LocalJobRunner: Starting task: attempt_local1582630093_0001_r_000000_0
org.apache.hadoop.mapred.ReduceTask: Using ShuffleConsumerPlugin: FooPlugin
在映射完成後開始減少任務。我設置mapreduce.job.reduce.slowstart.completedmaps
到0.0
作業的建議here,但它並沒有任何區別。
我使用Hadoop 2.5.1