in
compareTables cur_tbl upd_tbl
+checkInstanceMove :: Table -- original Table
+ -> Instance.Instance -- instance to move
+ -> Table -- best new table for this instance
+checkInstanceMove ini_tbl target =
+ let
+ Table ini_nl _ _ _ = ini_tbl
+ opdx = Instance.pnode target
+ osdx = Instance.snode target
+ nodes = filter (\node -> let idx = Node.idx node
+ in idx /= opdx && idx /= osdx)
+ $ Container.elems ini_nl
+ aft_failover = checkSingleStep ini_tbl target ini_tbl Failover
+ in
+ -- iterate over the possible nodes for this instance
+ foldl'
+ (\ accu_p new_node ->
+ let
+ new_idx = Node.idx new_node
+ pmoves = [ReplacePrimary new_idx,
+ ReplaceSecondary new_idx]
+ in
+ foldl' -- while doing both possible moves
+ (checkSingleStep ini_tbl target) accu_p pmoves
+ ) aft_failover nodes
+
-- | Compute the best next move.
checkMove :: Table -- ^ The current solution
-> [Instance.Instance] -- ^ List of instances still to move
-> Table -- ^ The new solution
checkMove ini_tbl victims =
- let Table ini_nl _ _ ini_plc = ini_tbl
- best_tbl =
- foldl -- iterate over all instances, computing the best move
- (\ step_tbl target ->
- let
- opdx = Instance.pnode target
- osdx = Instance.snode target
- nodes = filter (\node -> let idx = Node.idx node
- in idx /= opdx && idx /= osdx)
- $ Container.elems ini_nl
- aft_failover = checkSingleStep ini_tbl
- target ini_tbl Failover
- next_tbl = -- iterate over the possible nodes for
- -- this instance
- foldl'
- (\ accu_p new_node ->
- let
- new_idx = Node.idx new_node
- pmoves = [ReplacePrimary new_idx,
- ReplaceSecondary new_idx]
- in
- foldl' -- while doing both possible moves
- (checkSingleStep ini_tbl target) accu_p pmoves
- ) aft_failover nodes
- in
- compareTables step_tbl next_tbl
- ) ini_tbl victims
+ let Table _ _ _ ini_plc = ini_tbl
+ -- iterate over all instances, computing the best move
+ best_tbl = foldl'
+ (\ step_tbl elem -> compareTables step_tbl $
+ checkInstanceMove ini_tbl elem)
+ ini_tbl victims
in let
Table _ _ _ best_plc = best_tbl
(target, _, _) = head best_plc
+ -- remove the last placed instance from the victims list, it will
+ -- get another chance the next round
vtail = filter (\inst -> Instance.idx inst /= target) victims
in
if length best_plc == length ini_plc then -- no advancement