我正在尝试在Azure实例上安装Open Edx Insights。 LMS和Insights都在同一盒子上。作为安装的一部分，我已经通过yml脚本安装了Hadoop，hive等。现在，下一条指令是测试hadoop的安装，并且该文档要求计算“ pi”的值。为此，他们给出了以下命令：
hadoop jar hadoop*/share/hadoop/mapreduce/hadoop-mapreduce-examples*.jar pi 2 100
但是在我运行此命令后，它给出了错误：
hadoop@MillionEdx:~$ hadoop jar hadoop*/share/hadoop/mapreduce/hadoop-mapreduce-examples*.jar pi 2 100
Unknown program 'hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.2.jar' chosen.
Valid program names are:
aggregatewordcount: An Aggregate based map/reduce program that counts the words in the input files.
aggregatewordhist: An Aggregate based map/reduce program that computes the histogram of the words in the input files. bbp: A map/reduce program that uses Bailey-Borwein-Plouffe to compute exact digits of Pi.
dbcount: An example job that count the pageview counts from a database.
distbbp: A map/reduce program that uses a BBP-type formula to compute exact bits of Pi.
grep: A map/reduce program that counts the matches of a regex in the input.
join: A job that effects a join over sorted, equally partitioned datasets
multifilewc: A job that counts words from several files.
pentomino: A map/reduce tile laying program to find solutions to pentomino problems.
pi: A map/reduce program that estimates Pi using a quasi-Monte Carlo method.
randomtextwriter: A map/reduce program that writes 10GB of random textual data per node.
randomwriter: A map/reduce program that writes 10GB of random data per node.
secondarysort: An example defining a secondary sort to the reduce.
sort: A map/reduce program that sorts the data written by the random writer.
sudoku: A sudoku solver.
teragen: Generate data for the terasort
terasort: Run the terasort
teravalidate: Checking results of terasort
wordcount: A map/reduce program that counts the words in the input files.
wordmean: A map/reduce program that counts the average length of the words in the input files.
wordmedian: A map/reduce program that counts the median length of the words in the input files.
wordstandarddeviation: A map/reduce program that counts the standard deviation of the length of the words in the input files.
我尝试了许多尝试，例如尝试为Pi赋予完全限定的名称，但我从未获得pi的价值。请提出一些解决方法。
预先感谢。
答案 0 :(得分：0)
需要检查与Hadoop-mapreduce 2.7.2兼容的Java版本。
这可能是因为与Java版本相对应的jar文件错误。