Hi Pedro, If you're trying to compile 0.20.1, that version is pre-project-split. There's only one jar because it predates the point at which Hadoop was split into common/hdfs/MR. I've answered the specific questions below:
On Mon, Nov 23, 2009 at 2:39 PM, psdc1978 <[email protected]> wrote: > Hi all, > > > 1 - I'm trying to compile hadoop-0.20.1 but I'm facing several > errors. Hadoop includes several subprojects, but these subprojects > are all compiled in one file called hadoop-0.20.1-core.jar. If I just > want to update the code in the MapReduce component, do I have to > compile all the project? > In 0.20.1, yes. But it compiles quickly - only a couple minutes. > > 2 - Why Hadoop only have one jar for all the project? For example, > MapReduce subcomponent could be inside mapreduce.jar, Common > subcomponent could be inside common.jar, HDFS subcomponent could be > inside hdfs.jar, etc. > > As noted above, 0.20.1 is pre-split. In 0.21 and above, it will be separate jars as you expected. > 3 - Is there any tutorial that helps how to compile Hadoop, > especially only the MapReduce component? > > In 0.20.1, you can't do just one component, really. "ant bin-package" is a good way to compile that won't require a lot of other junk on your system. > 4 - Should I try to compile MapReduce in windows with Cygwin, or > should I compile inside Ubuntu? > > Ubuntu should be easier, though I'm told it's possible to do so in Cygwin. -Todd
