As HDFS-2246 itself states in one comment:
HDFS-347 discusses ways to optimize reads for local clients. A clean
design is fairly involved. A shortcut has been proposed where the
client access the hdfs file blocks directly; this works if the client
is the same user/group as the DN daemon. This is non-invasive and is a
good short term solution till HDFS-347 is completed.
HDFS-347, when done, would not have the user/group limitation (you may
call that a security/permissions problem as well), among other things.
Going over the JIRA's comments should give you more insight :)
On Mon, Oct 8, 2012 at 3:36 PM, jlei liu <[EMAIL PROTECTED]> wrote:
> The two issues both implement DFSClient to directly open data blocks that
> happen to be on the same machine function. What are advantage of HDFS-347？