On Fri, Apr 19, 2013 at 3:36 AM, Aaron T. Myers <atm@cloudera.com> wrote:
> On Fri, Apr 19, 2013 at 6:53 AM, Tsz Wo Sze <szetszwo@yahoo.com> wrote:
>
> > HdfsAdmin is also for admin operations. However, createSnapshot etc
> > methods aren't.
> >
>
> I agree that they're not administrative operations in the sense that they
> don't strictly require super user privilege, but they are "administrative"
> in the sense that they will most-often be used by those administering HDFS.
> The HdfsAdmin class should not be construed to contain only operations
> which require super user privilege, even though that happens to be the case
> right now. It's intended as just a public API for HDFS-specific operations.
>
> Regardless, my point is not necessarily that these operations should go
> into the HdfsAdmin class, but rather that they shouldn't go into the
> FileSystem class, since the snapshots API doesn't seem to me like it will
> generalize to other FileSystem implementations.
>
>
Agreed. The cases of WAFL/ZFS were brought up -- in those file systems,
even if users may take snapshots, they're done using FS-specific APIs
rather than any standard Linux interface. So, I'm in favor of either
putting the APIs in HdfsAdmin, or alternatively in DistributedFileSystem,
forcing a user to down-cast if they want to use the HDFS-specific operation.
-Todd
--
Todd Lipcon
Software Engineer, Cloudera
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