On Fri, Apr 19, 2013 at 3:36 AM, Aaron T. Myers <a...@cloudera.com> wrote:
> On Fri, Apr 19, 2013 at 6:53 AM, Tsz Wo Sze <szets...@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
