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Hadoop MapReduce WordCount示例缺陷？(Hadoop MapReduce WordCount example flaw?)

 参考基本的WordCount示例： https ： //hadoop.apache.org/docs/current/hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapReduceTutorial.html我知道HDFS按块和地图划分文件任务适用于单个块。 因此，无法保证地图任务分析的块不会包含在下一个块中继续的单词，从而导致错误（一个单词计数两次）。 我知道这是一个例子，并且总是以小文件显示，但在现实场景中不会出现问题？ 

With reference to the basic WordCount example: https://hadoop.apache.org/docs/current/hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapReduceTutorial.html I know that HDFS divide files in blocks, and maps tasks works on a single block. So there is no guarantee the block analyzed by a map task would not contain a word continuing in the next block, causing a mistake ( one word counted twice ). I know this is an example, and is always shown with small file, but wouldn't be a problem in real world scenarios?

原文：https://stackoverflow.com/questions/35424651
更新时间：2023-08-10 10:08

最满意答案

 可能是，根据http://caniuse.com/#feat=css-masks不支持 
 

 根据MDN，你可以在Firefox 3.5中使用mask for Firefox： 
 

 https://developer.mozilla.org/en/CSS/mask 
 

 但是，掩码需要SVG图像作为掩码。 您可以将SVG图像base-64编码到样式表中，也可以使用SVG图像文件。 

May be, It is not supported according to http://caniuse.com/#feat=css-masks
 

According to MDN, you can just use mask for Firefox, as of Firefox 3.5:
 

https://developer.mozilla.org/en/CSS/mask
 

However, mask requires an SVG image to act as the mask. You might be able to base-64 encode your SVG image into your stylesheet, or you can use an SVG image file.

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