This patch adds a periodic healing mechanism into the monitor module and
monitoring plugins. With this change, the heal_reservations() method of
resource plugin was changed to receive a period (start/end_date
arguments) to heal.
This change is for not healing (reallocating) all of reservations for
failed resources immediately because failed resources are expected to
recover sometime in the future. The monitor tries to heal only
reservations which are active or will start soon. Remaining reservations
are expected to be healed by the periodic healing.
Implements: blueprint healing-time
Change-Id: I6971c952fcde101ff2408f567fee9a7dab97b140
6d2950f3b0