This is great. Thanks, Todd. -C
On Wed, Jan 5, 2011 at 12:36 PM, Todd Lipcon <t...@cloudera.com> wrote: > I know many people use git, so wanted to share a neat tip I figured out this > morning that lets you graft the pre-split history into the post-split > repositories. I'm using git 1.7.1, not sure how new these features are. Here > are the steps: > > 1) Check out the git repos from git.apache.org into git/hadoop-common, > git/hadoop-mapreduce, and git/hadoop-hdfs > > 2) Set up the common repo as an "alternate object store" for mr and hdfs: > > $ echo "/path/to/git/hadoop-common/.git/objects" > > /path/to/git/hadoop-hdfs/.git/objects/info/alternates > $ echo "/path/to/git/hadoop-common/.git/objects" > > /path/to/git/hadoop-mapreduce/.git/objects/info/alternates > This allows you to look at hashes from common from within your MR or HDFS > repos. Note that if you move the paths later you'll have to update this > file! > > 3) Set up grafts for the beginning of MR/HDFS history to the pre-split > commit in common: > echo 546d96754ffee3142bcbbf4563c624c053d0ed0d > 6c16dc8cf2b28818c852e95302920a278d07ad0c > > git/hadoop-mapreduce/.git/info/grafts > echo 6a3ac690e493c7da45bbf2ae2054768c427fd0e1 > 6c16dc8cf2b28818c852e95302920a278d07ad0c >> git/hadoop-hdfs/.git/info/grafts > > Now when you use commands like git log --follow or git blame, it will pick > up changes from pre-split as if it were one repository. > > Hope others find this useful as well! > -Todd > -- > Todd Lipcon > Software Engineer, Cloudera >
