tier/dht: Fixing non atomic promotion/demotion w.r.t to frequency period

This fixes the ping-pong issue i.e files getting demoted immediately
after promition, caused by off-sync promotion/demotion processes.
The solution is do promotion/demotion refering to the system time.
To have the fix working all the file serving nodes should have
thier system time synchronized with each other either manually or
using a NTP Server.

NOTE: The ping-pong issue can re-appear even with this fix, if the admin
have different promotion freq period and demotion freq period, but this
would be under the control of the admin.

Backport of http://review.gluster.org/#/c/11110/ to 3.7.x:
> Change-Id: I1b33a5881d0cac143662ddb48e5b7b653aeb1271
> BUG: 1218717
> Signed-off-by: Joseph Fernandes <josferna@redhat.com>
> Reviewed-on: http://review.gluster.org/11110
> Reviewed-by: Dan Lambright <dlambrig@redhat.com>
> Tested-by: Dan Lambright <dlambrig@redhat.com>
> Tested-by: Gluster Build System <jenkins@build.gluster.com>

Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Change-Id: I81bd1d677487ebc0fc46df4980500102571de68e
BUG: 1230857
Reviewed-on: http://review.gluster.org/11191
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

0 files changed, 0 insertions, 0 deletions