As far as I know, nobody is working on this at the moment. There are a lot of issues that would need to be worked through before we could enable symlinks in production.
We never quite agreed on the semantics of how symlinks should work... for example, some people advocated that listing a directory should list the resolved names of all symlinks in it, while others argued that this would impose too great a performance load on clients listing directories with symlinks. Similarly, some people argued that cross-filesystem symlinks should be banned, partly because they can't be optimized very effectively. Then there were a bunch of security issues. Basically any higher-level software that is relying on path-based access will have problems with symlinks. For example, Hive assumes that if you limit a user's access to just things under /home/username, then you have effectively sandboxed that person. But if you can create a symlink from /home/username/foo to /foo, then you've effectively broken out of Hive's sandbox. Since Hive often runs with elevated permissions, and is willing access files under /home/username with those permissions, this would be disastrous. Hive is just one example, of course... basically we'd have to audit all software using HDFS for this kind of problem before enabling symlinks. You can see a list of all these issues and more at: https://issues.apache.org/jira/browse/HADOOP-10019. best, Colin On Thu, Dec 25, 2014 at 12:30 PM, Ananth Gundabattula <agundabatt...@gmail.com> wrote: > Hello All, > > Happy holidays. > > > I was wondering if Symbolic links would be re-enabled anytime in the near > future ? https://issues.apache.org/jira/browse/HADOOP-10020 > > I am using CDH VM and the moment I try to use the > FileContext.createSymlink() I get an error stating " Symbolic links not > supported" message ( UnsupportedOperationException ). The release notes > from CDH states that HADOOP-10020 is currently in the binary release. > > Is there any expected time line for this feature to be put back into the > main trunk ? If it is already, could anyone point me to the hadoop release > that the symbolic link has been reenabled ? > > Thanks for your time. > > > Regards, > Ananth
