Thanks for the response Colin. On Thu, Jan 1, 2015 at 11:12 AM, Colin McCabe <cmcc...@alumni.cmu.edu> wrote:
> 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 >
