如何从Hadoop的hdfs文件中删除一些数据

Question

I'd uploaded 50GB data on Hadoop cluster. But Now i want to delete first row of data file. This is time consuming if i remove that data & change manually. Then upload it again on HDFS. Please reply me.

Answer 1

HDFS files are immutable ( for all practical purposes ).

You need to upload the modified file(s). You can do the change programatically with a M/R job that does a near-identity transformation, eg. running a streaming shell script that does sed , but the gist of it that you need to create new files, HDFS files cannot be edited.