@Harsh, I sometimes get similar thoughts :P. But wonder if there is something can be done.
@Bobby, Thanks for elaborating the strange reason. :) @Praveenesh, Yes, you can do away with sourcing of hadoop-config.sh and set all the necessary variables by hand. On Wed, Feb 1, 2012 at 10:38 PM, Harsh J <[email protected]> wrote: > Personal opinion here: For branch-1, I do think the earlier tarball > structure was better. I do not see why it had to change for this > version at least. Possibly was changed during all the work of adding > packaging-related scripts for rpm/deb into Hadoop itself, but the > tarball right now is not as usable as was before, and the older format > would've still worked today. > > On Wed, Feb 1, 2012 at 10:31 PM, Robert Evans <[email protected]> wrote: > > I think it comes down to a long history of splitting and then remerging > the hadoop project. I could be wrong about a lot of this so take it worth > a grain of salt. Hadoop originally, and still is on 1.0 a single project. > HDFS, mapreduce and common are all compiled together into a single jar > hadoop-core. In that respect HADOOP_HOME made a lot of since because it > was a single thing, with some dependencies that needed to be found by some > shell scripts. > > > > Fast forward the projects were split, HADOOP_HOME was deprecated, and > HADOOP_COMMON_HOME, HADOOP_MAPRED_HOME, and HADOOP_HDFS_HOME were born. > But if we install them all into a single tree it is a pain to configure > all of these to point to the same place, but HADOOP_HOME is deprecated, so > HADOOP_PREFIX was born. NOTE: like was stated before all of these are > supposed to be hidden from the end user and are intended more towards > packaging and deploying hadoop. Also the process is not done and it is > likely to change further. > > > > --Bobby Evans > > > > On 2/1/12 8:10 AM, "praveenesh kumar" <[email protected]> wrote: > > > > Interesting and strange. > > but are there any reason for setting $HADOOP_HOME to $HADOOP_PREFIX in > > hadoop-conf.sh > > and then checking in /bin/hadoop.sh whether $HADOOP_HOME is not equal to > "" > > > > I mean if I comment out the export HADOOP_HOME=${HADOOP_PREFIX} in > > hadoop-conf.sh, does it make any difference ? > > > > Thanks, > > Praveenesh > > > > On Wed, Feb 1, 2012 at 6:04 PM, Prashant Sharma <[email protected] > >wrote: > > > >> I think you have misunderstood something. AFAIK or understand these > >> variables are set automatically when you run a script. it's name is > obscure > >> for some strange reason. ;). > >> > >> Warning: $HADOOP_HOME is deprecated is always there. whether the > variable > >> is set or not. Why? > >> Because the hadoop-config is sourced in all scripts. And all it does is > >> sets HADOOP_PREFIX as HADOOP_HOME. I think this can be reported as a > bug. > >> > >> -P > >> > >> > >> On Wed, Feb 1, 2012 at 5:46 PM, praveenesh kumar <[email protected] > >> >wrote: > >> > >> > Does anyone have idea on Why $HADOOP_PREFIX was introduced instead of > >> > $HADOOP_HOME in hadoop 0.20.205 ? > >> > > >> > I believe $HADOOP_HOME was not giving any troubles or is there a > >> reason/new > >> > feature that require $HADOOP_PREFIX to be added ? > >> > > >> > Its a kind of funny, but I got habitual of using $HADOOP_HOME. Just > >> curious > >> > to know for this change. > >> > Also, there are some old packages ( I am not referring > apache/cloudera/or > >> > any hadoop distribution ), that depends on hadoop that still uses > >> > $HADOOP_HOME inside. So its kind of weird when you use those packages, > >> you > >> > still get warning messages even though its suppressed from Hadoop > side. > >> > > >> > > >> > Thanks, > >> > Praveenesh > >> > > >> > > > > > > -- > Harsh J > Customer Ops. Engineer > Cloudera | http://tiny.cloudera.com/about >
