Hello,
I am complete Hadoop and MR newbiew, so please help me with following. I can see that primary way to submit Hadoop MR job is via following command (wordcount example): hadoop jar wordcount.jar org.mycompany.WordCount 1. Although, looking at all MR examples out there, I see this "hadooo jar" command used for submitting MR jobs, but actually it has nothing specific with MR job submissions, it just calls static "main" method, similar to plain "java" command, and this main method can just print "Hello world" on console and have no business with MR framework, right? 2. If above is true, and I assume it is, what is the difference with using plain java -jar in place of "hadoop jar"? Both call static "main" method, and this method could submit MR job via JobClient class, right? 3. On Hadoop docs ( <http://hadoop.apache.org/docs/r1.0.4/commands_manual.html#Generic+Options> http://hadoop.apache.org/docs/r1.0.4/commands_manual.html#Generic+Options ), I see that -libjars options is only present in "hadoop job" command, but not in "hadoop jar", and later is usually used (for some unknown reason because former also has -submit ooption?) for submitting jobs, so my question is does that mean that when using "jar" command I should only priovde thrid-party libs via "fat jar"? Regards, Vjeran
