我注意到,通常当HAMOOU集群群集不忙的时候,在地图面完全完成之前,会减少侧面开始进展?这怎么可能?我记得在某个地方读到的降低进度指标有些误导,但不能确切记得。 有人能对此说清楚吗?
33 1 / 3 3 1 1 / 3 1 1 3 3 2 / 3 /sub>。
除了已经给出的答案外,该行为受地图属性 mapred. deduce. slowstart.fulled.maps 的控制,该属性是地图任务的百分比(0-1),必须在复制阶段开始之前完成。
这是因为 缩放符必须将地图输出复制到节点, 任务会运行。 如果一个地图任务已完成并承诺了输出, 您可以直接将它传输并合并到已有的缩放符中的数据中 。
这样就可以省下很多时间 而不是等到所有的地图绘制完成。
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