-}
+{-
+
+Copyright (C) 2009 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+-}
+
module Ganeti.HTools.Cluster
(
-- * Types
- NameList
- , Placement
+ Placement
, Solution(..)
, Table(..)
, Removal
-- * IAllocator functions
, allocateOnSingle
, allocateOnPair
+ , tryAlloc
+ , tryReloc
) where
import Data.List
import Ganeti.HTools.Types
import Ganeti.HTools.Utils
--- | A separate name for the cluster score type
+-- * Types
+
+-- | A separate name for the cluster score type.
type Score = Double
-- | The description of an instance placement.
type Placement = (Idx, Ndx, Ndx, Score)
-{- | A cluster solution described as the solution delta and the list
-of placements.
-
--}
+-- | A cluster solution described as the solution delta and the list
+-- of placements.
data Solution = Solution Int [Placement]
deriving (Eq, Ord, Show)
--- | Returns the delta of a solution or -1 for Nothing
-solutionDelta :: Maybe Solution -> Int
-solutionDelta sol = case sol of
- Just (Solution d _) -> d
- _ -> -1
-
-- | A removal set.
data Removal = Removal Node.List [Instance.Instance]
data Table = Table Node.List Instance.List Score [Placement]
deriving (Show)
--- General functions
+-- * Utility functions
+
+-- | Returns the delta of a solution or -1 for Nothing.
+solutionDelta :: Maybe Solution -> Int
+solutionDelta sol = case sol of
+ Just (Solution d _) -> d
+ _ -> -1
-- | Cap the removal list if needed.
capRemovals :: [a] -> Int -> [a]
verifyN1 :: [Node.Node] -> [Node.Node]
verifyN1 nl = filter Node.failN1 nl
-{-| Add an instance and return the new node and instance maps. -}
+{-| Computes the pair of bad nodes and instances.
+
+The bad node list is computed via a simple 'verifyN1' check, and the
+bad instance list is the list of primary and secondary instances of
+those nodes.
+
+-}
+computeBadItems :: Node.List -> Instance.List ->
+ ([Node.Node], [Instance.Instance])
+computeBadItems nl il =
+ let bad_nodes = verifyN1 $ getOnline nl
+ bad_instances = map (\idx -> Container.find idx il) $
+ sort $ nub $ concat $
+ map (\ n -> (Node.slist n) ++ (Node.plist n)) bad_nodes
+ in
+ (bad_nodes, bad_instances)
+
+-- | Compute the total free disk and memory in the cluster.
+totalResources :: Node.List -> (Int, Int)
+totalResources nl =
+ foldl'
+ (\ (mem, dsk) node -> (mem + (Node.f_mem node),
+ dsk + (Node.f_dsk node)))
+ (0, 0) (Container.elems nl)
+
+-- | Compute the mem and disk covariance.
+compDetailedCV :: Node.List -> (Double, Double, Double, Double, Double)
+compDetailedCV nl =
+ let
+ all_nodes = Container.elems nl
+ (offline, nodes) = partition Node.offline all_nodes
+ mem_l = map Node.p_mem nodes
+ dsk_l = map Node.p_dsk nodes
+ mem_cv = varianceCoeff mem_l
+ dsk_cv = varianceCoeff dsk_l
+ n1_l = length $ filter Node.failN1 nodes
+ n1_score = (fromIntegral n1_l) / (fromIntegral $ length nodes)
+ res_l = map Node.p_rem nodes
+ res_cv = varianceCoeff res_l
+ offline_inst = sum . map (\n -> (length . Node.plist $ n) +
+ (length . Node.slist $ n)) $ offline
+ online_inst = sum . map (\n -> (length . Node.plist $ n) +
+ (length . Node.slist $ n)) $ nodes
+ off_score = (fromIntegral offline_inst) /
+ (fromIntegral $ online_inst + offline_inst)
+ in (mem_cv, dsk_cv, n1_score, res_cv, off_score)
+
+-- | Compute the /total/ variance.
+compCV :: Node.List -> Double
+compCV nl =
+ let (mem_cv, dsk_cv, n1_score, res_cv, off_score) = compDetailedCV nl
+ in mem_cv + dsk_cv + n1_score + res_cv + off_score
+
+-- | Compute online nodes from a Node.List
+getOnline :: Node.List -> [Node.Node]
+getOnline = filter (not . Node.offline) . Container.elems
+
+-- * hn1 functions
+
+-- | Add an instance and return the new node and instance maps.
addInstance :: Node.List -> Instance.Instance ->
Node.Node -> Node.Node -> Maybe Node.List
addInstance nl idata pri sec =
removeInstances :: Node.List -> [Instance.Instance] -> Node.List
removeInstances = foldl' removeInstance
--- | Compute the total free disk and memory in the cluster.
-totalResources :: Container.Container Node.Node -> (Int, Int)
-totalResources nl =
- foldl'
- (\ (mem, dsk) node -> (mem + (Node.f_mem node),
- dsk + (Node.f_dsk node)))
- (0, 0) (Container.elems nl)
-{- | Compute a new version of a cluster given a solution.
+{-| Compute a new version of a cluster given a solution.
This is not used for computing the solutions, but for applying a
(known-good) solution to the original cluster for final display.
) nc odxes
--- First phase functions
+-- ** First phase functions
-{- | Given a list 1,2,3..n build a list of pairs [(1, [2..n]), (2,
+{-| Given a list 1,2,3..n build a list of pairs [(1, [2..n]), (2,
[3..n]), ...]
-}
in
aux_fn count1 names1 []
-{- | Computes the pair of bad nodes and instances.
-
-The bad node list is computed via a simple 'verifyN1' check, and the
-bad instance list is the list of primary and secondary instances of
-those nodes.
-
--}
-computeBadItems :: Node.List -> Instance.List ->
- ([Node.Node], [Instance.Instance])
-computeBadItems nl il =
- let bad_nodes = verifyN1 $ filter (not . Node.offline) $ Container.elems nl
- bad_instances = map (\idx -> Container.find idx il) $
- sort $ nub $ concat $
- map (\ n -> (Node.slist n) ++ (Node.plist n)) bad_nodes
- in
- (bad_nodes, bad_instances)
-
-
-{- | Checks if removal of instances results in N+1 pass.
+{-| Checks if removal of instances results in N+1 pass.
Note: the check removal cannot optimize by scanning only the affected
nodes, since the cluster is known to be not healthy; only the check
Just $ Removal nx victims
--- | Computes the removals list for a given depth
+-- | Computes the removals list for a given depth.
computeRemovals :: Node.List
-> [Instance.Instance]
-> Int
computeRemovals nl bad_instances depth =
map (checkRemoval nl) $ genNames depth bad_instances
--- Second phase functions
+-- ** Second phase functions
--- | Single-node relocation cost
+-- | Single-node relocation cost.
nodeDelta :: Ndx -> Ndx -> Ndx -> Int
nodeDelta i p s =
if i == p || i == s then
else
1
-{-| Compute best solution.
-
- This function compares two solutions, choosing the minimum valid
- solution.
--}
+-- | Compute best solution.
+--
+-- This function compares two solutions, choosing the minimum valid
+-- solution.
compareSolutions :: Maybe Solution -> Maybe Solution -> Maybe Solution
compareSolutions a b = case (a, b) of
(Nothing, x) -> x
(x, Nothing) -> x
(x, y) -> min x y
--- | Compute best table. Note that the ordering of the arguments is important.
-compareTables :: Table -> Table -> Table
-compareTables a@(Table _ _ a_cv _) b@(Table _ _ b_cv _ ) =
- if a_cv > b_cv then b else a
-
-- | Check if a given delta is worse then an existing solution.
tooHighDelta :: Maybe Solution -> Int -> Int -> Bool
tooHighDelta sol new_delta max_delta =
) accu_p nodes
) prev_sol nodes
--- | Apply a move
+{-| Auxiliary function for solution computation.
+
+We write this in an explicit recursive fashion in order to control
+early-abort in case we have met the min delta. We can't use foldr
+instead of explicit recursion since we need the accumulator for the
+abort decision.
+
+-}
+advanceSolution :: [Maybe Removal] -- ^ The removal to process
+ -> Int -- ^ Minimum delta parameter
+ -> Int -- ^ Maximum delta parameter
+ -> Maybe Solution -- ^ Current best solution
+ -> Maybe Solution -- ^ New best solution
+advanceSolution [] _ _ sol = sol
+advanceSolution (Nothing:xs) m n sol = advanceSolution xs m n sol
+advanceSolution ((Just (Removal nx removed)):xs) min_d max_d prev_sol =
+ let new_sol = checkPlacement nx removed [] 0 prev_sol max_d
+ new_delta = solutionDelta $! new_sol
+ in
+ if new_delta >= 0 && new_delta <= min_d then
+ new_sol
+ else
+ advanceSolution xs min_d max_d new_sol
+
+-- | Computes the placement solution.
+solutionFromRemovals :: [Maybe Removal] -- ^ The list of (possible) removals
+ -> Int -- ^ Minimum delta parameter
+ -> Int -- ^ Maximum delta parameter
+ -> Maybe Solution -- ^ The best solution found
+solutionFromRemovals removals min_delta max_delta =
+ advanceSolution removals min_delta max_delta Nothing
+
+{-| Computes the solution at the given depth.
+
+This is a wrapper over both computeRemovals and
+solutionFromRemovals. In case we have no solution, we return Nothing.
+
+-}
+computeSolution :: Node.List -- ^ The original node data
+ -> [Instance.Instance] -- ^ The list of /bad/ instances
+ -> Int -- ^ The /depth/ of removals
+ -> Int -- ^ Maximum number of removals to process
+ -> Int -- ^ Minimum delta parameter
+ -> Int -- ^ Maximum delta parameter
+ -> Maybe Solution -- ^ The best solution found (or Nothing)
+computeSolution nl bad_instances depth max_removals min_delta max_delta =
+ let
+ removals = computeRemovals nl bad_instances depth
+ removals' = capRemovals removals max_removals
+ in
+ solutionFromRemovals removals' min_delta max_delta
+
+-- * hbal functions
+
+-- | Compute best table. Note that the ordering of the arguments is important.
+compareTables :: Table -> Table -> Table
+compareTables a@(Table _ _ a_cv _) b@(Table _ _ b_cv _ ) =
+ if a_cv > b_cv then b else a
+
+-- | Applies an instance move to a given node list and instance.
applyMove :: Node.List -> Instance.Instance
-> IMove -> (Maybe Node.List, Instance.Instance, Ndx, Ndx)
-- Failover (f)
int_p = Node.removePri old_p inst
int_s = Node.removeSec old_s inst
new_nl = do -- Maybe monad
+ -- check that the current secondary can host the instance
+ -- during the migration
+ tmp_s <- Node.addPri int_s inst
+ let tmp_s' = Node.removePri tmp_s inst
new_p <- Node.addPri tgt_n inst
- new_s <- Node.addSec int_s inst new_pdx
+ new_s <- Node.addSec tmp_s' inst new_pdx
return $ Container.add new_pdx new_p $
Container.addTwo old_pdx int_p old_sdx new_s nl
in (new_nl, Instance.setPri inst new_pdx, new_pdx, old_sdx)
Container.addTwo old_sdx new_p old_pdx int_p nl
in (new_nl, Instance.setBoth inst old_sdx new_sdx, old_sdx, new_sdx)
+-- | Tries to allocate an instance on one given node.
allocateOnSingle :: Node.List -> Instance.Instance -> Node.Node
-> (Maybe Node.List, Instance.Instance)
allocateOnSingle nl inst p =
return $ Container.add new_pdx new_p nl
in (new_nl, Instance.setBoth inst new_pdx Node.noSecondary)
+-- | Tries to allocate an instance on a given pair of nodes.
allocateOnPair :: Node.List -> Instance.Instance -> Node.Node -> Node.Node
-> (Maybe Node.List, Instance.Instance)
allocateOnPair nl inst tgt_p tgt_s =
return $ Container.addTwo new_pdx new_p new_sdx new_s nl
in (new_nl, Instance.setBoth inst new_pdx new_sdx)
+-- | Tries to perform an instance move and returns the best table
+-- between the original one and the new one.
checkSingleStep :: Table -- ^ The original table
-> Instance.Instance -- ^ The instance to move
-> Table -- ^ The current best table
else
best_tbl
-{- | Auxiliary function for solution computation.
-
-We write this in an explicit recursive fashion in order to control
-early-abort in case we have met the min delta. We can't use foldr
-instead of explicit recursion since we need the accumulator for the
-abort decision.
-
--}
-advanceSolution :: [Maybe Removal] -- ^ The removal to process
- -> Int -- ^ Minimum delta parameter
- -> Int -- ^ Maximum delta parameter
- -> Maybe Solution -- ^ Current best solution
- -> Maybe Solution -- ^ New best solution
-advanceSolution [] _ _ sol = sol
-advanceSolution (Nothing:xs) m n sol = advanceSolution xs m n sol
-advanceSolution ((Just (Removal nx removed)):xs) min_d max_d prev_sol =
- let new_sol = checkPlacement nx removed [] 0 prev_sol max_d
- new_delta = solutionDelta $! new_sol
- in
- if new_delta >= 0 && new_delta <= min_d then
- new_sol
- else
- advanceSolution xs min_d max_d new_sol
-
--- | Computes the placement solution.
-solutionFromRemovals :: [Maybe Removal] -- ^ The list of (possible) removals
- -> Int -- ^ Minimum delta parameter
- -> Int -- ^ Maximum delta parameter
- -> Maybe Solution -- ^ The best solution found
-solutionFromRemovals removals min_delta max_delta =
- advanceSolution removals min_delta max_delta Nothing
-
-{- | Computes the solution at the given depth.
-
-This is a wrapper over both computeRemovals and
-solutionFromRemovals. In case we have no solution, we return Nothing.
-
--}
-computeSolution :: Node.List -- ^ The original node data
- -> [Instance.Instance] -- ^ The list of /bad/ instances
- -> Int -- ^ The /depth/ of removals
- -> Int -- ^ Maximum number of removals to process
- -> Int -- ^ Minimum delta parameter
- -> Int -- ^ Maximum delta parameter
- -> Maybe Solution -- ^ The best solution found (or Nothing)
-computeSolution nl bad_instances depth max_removals min_delta max_delta =
- let
- removals = computeRemovals nl bad_instances depth
- removals' = capRemovals removals max_removals
- in
- solutionFromRemovals removals' min_delta max_delta
-
--- Solution display functions (pure)
+-- * Alocation functions
+
+-- | Try to allocate an instance on the cluster.
+tryAlloc :: (Monad m) =>
+ Node.List -- ^ The node list
+ -> Instance.List -- ^ The instance list
+ -> Instance.Instance -- ^ The instance to allocate
+ -> Int -- ^ Required number of nodes
+ -> m [(Maybe Node.List, Instance.Instance, [Node.Node])]
+ -- ^ Possible solution list
+tryAlloc nl _ inst 2 =
+ let all_nodes = getOnline nl
+ all_pairs = liftM2 (,) all_nodes all_nodes
+ ok_pairs = filter (\(x, y) -> Node.idx x /= Node.idx y) all_pairs
+ sols = map (\(p, s) -> let (mnl, i) = allocateOnPair nl inst p s
+ in (mnl, i, [p, s]))
+ ok_pairs
+ in return sols
+
+tryAlloc nl _ inst 1 =
+ let all_nodes = getOnline nl
+ sols = map (\p -> let (mnl, i) = allocateOnSingle nl inst p
+ in (mnl, i, [p]))
+ all_nodes
+ in return sols
+
+tryAlloc _ _ _ reqn = fail $ "Unsupported number of alllocation \
+ \destinations required (" ++ (show reqn) ++
+ "), only two supported"
+
+-- | Try to allocate an instance on the cluster.
+tryReloc :: (Monad m) =>
+ Node.List -- ^ The node list
+ -> Instance.List -- ^ The instance list
+ -> Idx -- ^ The index of the instance to move
+ -> Int -- ^ The numver of nodes required
+ -> [Ndx] -- ^ Nodes which should not be used
+ -> m [(Maybe Node.List, Instance.Instance, [Node.Node])]
+ -- ^ Solution list
+tryReloc nl il xid 1 ex_idx =
+ let all_nodes = getOnline nl
+ inst = Container.find xid il
+ ex_idx' = (Instance.pnode inst):ex_idx
+ valid_nodes = filter (not . flip elem ex_idx' . Node.idx) all_nodes
+ valid_idxes = map Node.idx valid_nodes
+ sols1 = map (\x -> let (mnl, i, _, _) =
+ applyMove nl inst (ReplaceSecondary x)
+ in (mnl, i, [Container.find x nl])
+ ) valid_idxes
+ in return sols1
+
+tryReloc _ _ _ reqn _ = fail $ "Unsupported number of relocation \
+ \destinations required (" ++ (show reqn) ++
+ "), only one supported"
+
+-- * Formatting functions
-- | Given the original and final nodes, computes the relocation description.
computeMoves :: String -- ^ The instance name
printf "migrate -f %s" i,
printf "replace-disks -n %s %s" d i])
-{-| Converts a placement to string format -}
-printSolutionLine :: Node.List
- -> Instance.List
- -> Int
- -> Int
- -> Placement
- -> Int
+-- | Converts a placement to string format.
+printSolutionLine :: Node.List -- ^ The node list
+ -> Instance.List -- ^ The instance list
+ -> Int -- ^ Maximum node name length
+ -> Int -- ^ Maximum instance name length
+ -> Placement -- ^ The current placement
+ -> Int -- ^ The index of the placement in
+ -- the solution
-> (String, [String])
printSolutionLine nl il nmlen imlen plc pos =
let
pmlen nstr c moves,
cmds)
+-- | Given a list of commands, prefix them with @gnt-instance@ and
+-- also beautify the display a little.
formatCmds :: [[String]] -> String
formatCmds cmd_strs =
unlines $
(map ("gnt-instance " ++) b)) $
zip [1..] cmd_strs
-{-| Converts a solution to string format -}
+-- | Converts a solution to string format.
printSolution :: Node.List
-> Instance.List
-> [Placement]
m_name = maximum . map (length . Node.name) $ snl
helper = Node.list m_name
header = printf
- "%2s %-*s %5s %5s %5s %5s %5s %5s %5s %5s %3s %3s %7s %7s"
+ "%2s %-*s %5s %5s %5s %5s %5s %5s %5s %5s %3s %3s %7s %7s %7s"
" F" m_name "Name"
"t_mem" "n_mem" "i_mem" "x_mem" "f_mem" "r_mem"
"t_dsk" "f_dsk"
- "pri" "sec" "p_fmem" "p_fdsk"
+ "pri" "sec" "p_fmem" "p_fdsk" "r_cpu"
in unlines $ (header:map helper snl)
--- | Compute the mem and disk covariance.
-compDetailedCV :: Node.List -> (Double, Double, Double, Double, Double)
-compDetailedCV nl =
- let
- all_nodes = Container.elems nl
- (offline, nodes) = partition Node.offline all_nodes
- mem_l = map Node.p_mem nodes
- dsk_l = map Node.p_dsk nodes
- mem_cv = varianceCoeff mem_l
- dsk_cv = varianceCoeff dsk_l
- n1_l = length $ filter Node.failN1 nodes
- n1_score = (fromIntegral n1_l) / (fromIntegral $ length nodes)
- res_l = map Node.p_rem nodes
- res_cv = varianceCoeff res_l
- offline_inst = sum . map (\n -> (length . Node.plist $ n) +
- (length . Node.slist $ n)) $ offline
- online_inst = sum . map (\n -> (length . Node.plist $ n) +
- (length . Node.slist $ n)) $ nodes
- off_score = (fromIntegral offline_inst) /
- (fromIntegral $ online_inst + offline_inst)
- in (mem_cv, dsk_cv, n1_score, res_cv, off_score)
-
--- | Compute the 'total' variance.
-compCV :: Node.List -> Double
-compCV nl =
- let (mem_cv, dsk_cv, n1_score, res_cv, off_score) = compDetailedCV nl
- in mem_cv + dsk_cv + n1_score + res_cv + off_score
-
+-- | Shows statistics for a given node list.
printStats :: Node.List -> String
printStats nl =
let (mem_cv, dsk_cv, n1_score, res_cv, off_score) = compDetailedCV nl
projects / ganeti-local / blobdiff