-}
+{-
+
+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
- NodeList
- , InstanceList
- , NameList
- , Placement
- , Solution(..)
+ Placement
+ , AllocSolution
, Table(..)
- , Removal
+ , Score
+ , IMove(..)
+ , CStats(..)
-- * Generic functions
, totalResources
-- * First phase functions
, computeBadItems
-- * Second phase functions
- , computeSolution
- , applySolution
, printSolution
, printSolutionLine
, formatCmds
, checkMove
, compCV
, printStats
- -- * Loading functions
- , loadData
+ -- * IAllocator functions
+ , tryAlloc
+ , tryReloc
+ , collapseFailures
) where
import Data.List
-import Data.Maybe (isNothing, fromJust)
import Text.Printf (printf)
import Data.Function
+import Control.Monad
import qualified Ganeti.HTools.Container as Container
import qualified Ganeti.HTools.Instance as Instance
import qualified Ganeti.HTools.Node as Node
+import Ganeti.HTools.Types
import Ganeti.HTools.Utils
-type NodeList = Container.Container Node.Node
-type InstanceList = Container.Container Instance.Instance
--- | The type used to hold idx-to-name mappings
-type NameList = [(Int, String)]
--- | 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 = (Int, Int, Int, Score)
-
-{- | A cluster solution described as the solution delta and the list
-of placements.
+type Placement = (Idx, Ndx, Ndx, Score)
--}
-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
+-- | Allocation\/relocation solution.
+type AllocSolution = ([FailMode], Int, Maybe (Score, AllocElement))
--- | A removal set.
-data Removal = Removal NodeList [Instance.Instance]
+-- | Allocation\/relocation element.
+type AllocElement = (Node.List, Instance.Instance, [Node.Node])
-- | An instance move definition
data IMove = Failover -- ^ Failover the instance (f)
- | ReplacePrimary Int -- ^ Replace primary (f, r:np, f)
- | ReplaceSecondary Int -- ^ Replace secondary (r:ns)
- | ReplaceAndFailover Int -- ^ Replace secondary, failover (r:np, f)
- | FailoverAndReplace Int -- ^ Failover, replace secondary (f, r:ns)
+ | ReplacePrimary Ndx -- ^ Replace primary (f, r:np, f)
+ | ReplaceSecondary Ndx -- ^ Replace secondary (r:ns)
+ | ReplaceAndFailover Ndx -- ^ Replace secondary, failover (r:np, f)
+ | FailoverAndReplace Ndx -- ^ Failover, replace secondary (f, r:ns)
deriving (Show)
-- | The complete state for the balancing solution
-data Table = Table NodeList InstanceList Score [Placement]
+data Table = Table Node.List Instance.List Score [Placement]
deriving (Show)
--- General functions
-
--- | Cap the removal list if needed.
-capRemovals :: [a] -> Int -> [a]
-capRemovals removals max_removals =
- if max_removals > 0 then
- take max_removals removals
- else
- removals
-
--- | Check if the given node list fails the N+1 check.
-verifyN1Check :: [Node.Node] -> Bool
-verifyN1Check nl = any Node.failN1 nl
+data CStats = CStats { cs_fmem :: Int -- ^ Cluster free mem
+ , cs_fdsk :: Int -- ^ Cluster free disk
+ , cs_amem :: Int -- ^ Cluster allocatable mem
+ , cs_adsk :: Int -- ^ Cluster allocatable disk
+ , cs_acpu :: Int -- ^ Cluster allocatable cpus
+ , cs_mmem :: Int -- ^ Max node allocatable mem
+ , cs_mdsk :: Int -- ^ Max node allocatable disk
+ , cs_mcpu :: Int -- ^ Max node allocatable cpu
+ , cs_imem :: Int -- ^ Instance used mem
+ , cs_idsk :: Int -- ^ Instance used disk
+ , cs_icpu :: Int -- ^ Instance used cpu
+ , cs_tmem :: Double -- ^ Cluster total mem
+ , cs_tdsk :: Double -- ^ Cluster total disk
+ , cs_tcpu :: Double -- ^ Cluster total cpus
+ , cs_xmem :: Int -- ^ Unnacounted for mem
+ , cs_nmem :: Int -- ^ Node own memory
+ , cs_score :: Score -- ^ The cluster score
+ , cs_ninst :: Int -- ^ The total number of instances
+ }
+
+-- * Utility functions
-- | Verifies the N+1 status and return the affected nodes.
verifyN1 :: [Node.Node] -> [Node.Node]
-verifyN1 nl = filter Node.failN1 nl
-
-{-| Add an instance and return the new node and instance maps. -}
-addInstance :: NodeList -> Instance.Instance ->
- Node.Node -> Node.Node -> Maybe NodeList
-addInstance nl idata pri sec =
- let pdx = Node.idx pri
- sdx = Node.idx sec
- in do
- pnode <- Node.addPri pri idata
- snode <- Node.addSec sec idata pdx
- new_nl <- return $ Container.addTwo sdx snode
- pdx pnode nl
- return new_nl
-
--- | Remove an instance and return the new node and instance maps.
-removeInstance :: NodeList -> Instance.Instance -> NodeList
-removeInstance nl idata =
- let pnode = Instance.pnode idata
- snode = Instance.snode idata
- pn = Container.find pnode nl
- sn = Container.find snode nl
- new_nl = Container.addTwo
- pnode (Node.removePri pn idata)
- snode (Node.removeSec sn idata) nl in
- new_nl
-
--- | Remove an instance and return the new node map.
-removeInstances :: NodeList -> [Instance.Instance] -> NodeList
-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.
-
-This is not used for computing the solutions, but for applying a
-(known-good) solution to the original cluster for final display.
-
-It first removes the relocated instances after which it places them on
-their new nodes.
-
- -}
-applySolution :: NodeList -> InstanceList -> [Placement] -> NodeList
-applySolution nl il sol =
- let odxes = map (\ (a, b, c, _) -> (Container.find a il,
- Node.idx (Container.find b nl),
- Node.idx (Container.find c nl))
- ) sol
- idxes = (\ (x, _, _) -> x) (unzip3 odxes)
- nc = removeInstances nl idxes
- in
- foldl' (\ nz (a, b, c) ->
- let new_p = Container.find b nz
- new_s = Container.find c nz in
- fromJust (addInstance nz a new_p new_s)
- ) nc odxes
-
+verifyN1 = filter Node.failN1
--- First phase functions
-
-{- | Given a list 1,2,3..n build a list of pairs [(1, [2..n]), (2,
- [3..n]), ...]
-
--}
-genParts :: [a] -> Int -> [(a, [a])]
-genParts l count =
- case l of
- [] -> []
- x:xs ->
- if length l < count then
- []
- else
- (x, xs) : (genParts xs count)
-
--- | Generates combinations of count items from the names list.
-genNames :: Int -> [b] -> [[b]]
-genNames count1 names1 =
- let aux_fn count names current =
- case count of
- 0 -> [current]
- _ ->
- concatMap
- (\ (x, xs) -> aux_fn (count - 1) xs (x:current))
- (genParts names count)
- in
- aux_fn count1 names1 []
-
-{- | Computes the pair of bad nodes and instances.
+{-| 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 :: NodeList -> InstanceList ->
+computeBadItems :: Node.List -> Instance.List ->
([Node.Node], [Instance.Instance])
computeBadItems nl il =
- let bad_nodes = verifyN1 $ Container.elems nl
- bad_instances = map (\idx -> Container.find idx il) $
- sort $ nub $ concat $
- map (\ n -> (Node.slist n) ++ (Node.plist n)) bad_nodes
+ let bad_nodes = verifyN1 $ getOnline nl
+ bad_instances = map (\idx -> Container.find idx il) .
+ sort . nub $
+ concatMap (\ n -> Node.slist n ++ Node.plist n) bad_nodes
in
(bad_nodes, bad_instances)
+emptyCStats :: CStats
+emptyCStats = CStats { cs_fmem = 0
+ , cs_fdsk = 0
+ , cs_amem = 0
+ , cs_adsk = 0
+ , cs_acpu = 0
+ , cs_mmem = 0
+ , cs_mdsk = 0
+ , cs_mcpu = 0
+ , cs_imem = 0
+ , cs_idsk = 0
+ , cs_icpu = 0
+ , cs_tmem = 0
+ , cs_tdsk = 0
+ , cs_tcpu = 0
+ , cs_xmem = 0
+ , cs_nmem = 0
+ , cs_score = 0
+ , cs_ninst = 0
+ }
+
+updateCStats :: CStats -> Node.Node -> CStats
+updateCStats cs node =
+ let CStats { cs_fmem = x_fmem, cs_fdsk = x_fdsk,
+ cs_amem = x_amem, cs_acpu = x_acpu, cs_adsk = x_adsk,
+ cs_mmem = x_mmem, cs_mdsk = x_mdsk, cs_mcpu = x_mcpu,
+ cs_imem = x_imem, cs_idsk = x_idsk, cs_icpu = x_icpu,
+ cs_tmem = x_tmem, cs_tdsk = x_tdsk, cs_tcpu = x_tcpu,
+ cs_xmem = x_xmem, cs_nmem = x_nmem, cs_ninst = x_ninst
+ }
+ = cs
+ inc_amem = Node.f_mem node - Node.r_mem node
+ inc_amem' = if inc_amem > 0 then inc_amem else 0
+ inc_adsk = Node.availDisk node
+ inc_imem = truncate (Node.t_mem node) - Node.n_mem node
+ - Node.x_mem node - Node.f_mem node
+ inc_icpu = Node.u_cpu node
+ inc_idsk = truncate (Node.t_dsk node) - Node.f_dsk node
+
+ in cs { cs_fmem = x_fmem + Node.f_mem node
+ , cs_fdsk = x_fdsk + Node.f_dsk node
+ , cs_amem = x_amem + inc_amem'
+ , cs_adsk = x_adsk + inc_adsk
+ , cs_acpu = x_acpu
+ , cs_mmem = max x_mmem inc_amem'
+ , cs_mdsk = max x_mdsk inc_adsk
+ , cs_mcpu = x_mcpu
+ , cs_imem = x_imem + inc_imem
+ , cs_idsk = x_idsk + inc_idsk
+ , cs_icpu = x_icpu + inc_icpu
+ , cs_tmem = x_tmem + Node.t_mem node
+ , cs_tdsk = x_tdsk + Node.t_dsk node
+ , cs_tcpu = x_tcpu + Node.t_cpu node
+ , cs_xmem = x_xmem + Node.x_mem node
+ , cs_nmem = x_nmem + Node.n_mem node
+ , cs_ninst = x_ninst + length (Node.plist node)
+ }
+
+-- | Compute the total free disk and memory in the cluster.
+totalResources :: Node.List -> CStats
+totalResources nl =
+ let cs = foldl' updateCStats emptyCStats . Container.elems $ nl
+ in cs { cs_score = compCV nl }
-{- | Checks if removal of instances results in N+1 pass.
+-- | Compute the mem and disk covariance.
+compDetailedCV :: Node.List -> (Double, 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)::Double
+ 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 = if offline_inst == 0
+ then 0::Double
+ else fromIntegral offline_inst /
+ fromIntegral (offline_inst + online_inst)::Double
+ cpu_l = map Node.p_cpu nodes
+ cpu_cv = varianceCoeff cpu_l
+ in (mem_cv, dsk_cv, n1_score, res_cv, off_score, cpu_cv)
+
+-- | Compute the /total/ variance.
+compCV :: Node.List -> Double
+compCV nl =
+ let (mem_cv, dsk_cv, n1_score, res_cv, off_score, cpu_cv) =
+ compDetailedCV nl
+ in mem_cv + dsk_cv + n1_score + res_cv + off_score + cpu_cv
-Note: the check removal cannot optimize by scanning only the affected
-nodes, since the cluster is known to be not healthy; only the check
-placement can make this shortcut.
+-- | Compute online nodes from a Node.List
+getOnline :: Node.List -> [Node.Node]
+getOnline = filter (not . Node.offline) . Container.elems
--}
-checkRemoval :: NodeList -> [Instance.Instance] -> Maybe Removal
-checkRemoval nl victims =
- let nx = removeInstances nl victims
- failN1 = verifyN1Check (Container.elems nx)
- in
- if failN1 then
- Nothing
- else
- Just $ Removal nx victims
-
-
--- | Computes the removals list for a given depth
-computeRemovals :: NodeList
- -> [Instance.Instance]
- -> Int
- -> [Maybe Removal]
-computeRemovals nl bad_instances depth =
- map (checkRemoval nl) $ genNames depth bad_instances
-
--- Second phase functions
-
--- | Single-node relocation cost
-nodeDelta :: Int -> Int -> Int -> Int
-nodeDelta i p s =
- if i == p || i == s then
- 0
- else
- 1
-
-{-| 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
+-- * 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
--- | Check if a given delta is worse then an existing solution.
-tooHighDelta :: Maybe Solution -> Int -> Int -> Bool
-tooHighDelta sol new_delta max_delta =
- if new_delta > max_delta && max_delta >=0 then
- True
- else
- case sol of
- Nothing -> False
- Just (Solution old_delta _) -> old_delta <= new_delta
-
-{-| Check if placement of instances still keeps the cluster N+1 compliant.
-
- This is the workhorse of the allocation algorithm: given the
- current node and instance maps, the list of instances to be
- placed, and the current solution, this will return all possible
- solution by recursing until all target instances are placed.
-
--}
-checkPlacement :: NodeList -- ^ The current node list
- -> [Instance.Instance] -- ^ List of instances still to place
- -> [Placement] -- ^ Partial solution until now
- -> Int -- ^ The delta of the partial solution
- -> Maybe Solution -- ^ The previous solution
- -> Int -- ^ Abort if the we go above this delta
- -> Maybe Solution -- ^ The new solution
-checkPlacement nl victims current current_delta prev_sol max_delta =
- let target = head victims
- opdx = Instance.pnode target
- osdx = Instance.snode target
- vtail = tail victims
- have_tail = (length vtail) > 0
- nodes = Container.elems nl
- iidx = Instance.idx target
- in
- foldl'
- (\ accu_p pri ->
- let
- pri_idx = Node.idx pri
- upri_delta = current_delta + nodeDelta pri_idx opdx osdx
- new_pri = Node.addPri pri target
- fail_delta1 = tooHighDelta accu_p upri_delta max_delta
- in
- if fail_delta1 || isNothing(new_pri) then accu_p
- else let pri_nl = Container.add pri_idx (fromJust new_pri) nl in
- foldl'
- (\ accu sec ->
- let
- sec_idx = Node.idx sec
- upd_delta = upri_delta +
- nodeDelta sec_idx opdx osdx
- fail_delta2 = tooHighDelta accu upd_delta max_delta
- new_sec = Node.addSec sec target pri_idx
- in
- if sec_idx == pri_idx || fail_delta2 ||
- isNothing new_sec then accu
- else let
- nx = Container.add sec_idx (fromJust new_sec) pri_nl
- upd_cv = compCV nx
- plc = (iidx, pri_idx, sec_idx, upd_cv)
- c2 = plc:current
- result =
- if have_tail then
- checkPlacement nx vtail c2 upd_delta
- accu max_delta
- else
- Just (Solution upd_delta c2)
- in compareSolutions accu result
- ) accu_p nodes
- ) prev_sol nodes
-
--- | Apply a move
-applyMove :: NodeList -> Instance.Instance
- -> IMove -> (Maybe NodeList, Instance.Instance, Int, Int)
+-- | Applies an instance move to a given node list and instance.
+applyMove :: Node.List -> Instance.Instance
+ -> IMove -> OpResult (Node.List, Instance.Instance, Ndx, Ndx)
-- Failover (f)
applyMove nl inst Failover =
let old_pdx = Instance.pnode inst
old_s = Container.find old_sdx nl
int_p = Node.removePri old_p inst
int_s = Node.removeSec old_s inst
- new_p = Node.addPri int_s inst
- new_s = Node.addSec int_p inst old_sdx
- new_nl = if isNothing(new_p) || isNothing(new_s) then Nothing
- else Just $ Container.addTwo old_pdx (fromJust new_s)
- old_sdx (fromJust new_p) nl
- in (new_nl, Instance.setBoth inst old_sdx old_pdx, old_sdx, old_pdx)
+ new_nl = do -- Maybe monad
+ new_p <- Node.addPri int_s inst
+ new_s <- Node.addSec int_p inst old_sdx
+ let new_inst = Instance.setBoth inst old_sdx old_pdx
+ return (Container.addTwo old_pdx new_s old_sdx new_p nl,
+ new_inst, old_sdx, old_pdx)
+ in new_nl
-- Replace the primary (f:, r:np, f)
applyMove nl inst (ReplacePrimary new_pdx) =
tgt_n = Container.find new_pdx nl
int_p = Node.removePri old_p inst
int_s = Node.removeSec old_s inst
- new_p = Node.addPri tgt_n inst
- new_s = Node.addSec int_s inst new_pdx
- new_nl = if isNothing(new_p) || isNothing(new_s) then Nothing
- else Just $ Container.add new_pdx (fromJust new_p) $
- Container.addTwo old_pdx int_p
- old_sdx (fromJust new_s) nl
- in (new_nl, Instance.setPri inst new_pdx, new_pdx, old_sdx)
+ 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 tmp_s' inst new_pdx
+ let new_inst = Instance.setPri inst new_pdx
+ return (Container.add new_pdx new_p $
+ Container.addTwo old_pdx int_p old_sdx new_s nl,
+ new_inst, new_pdx, old_sdx)
+ in new_nl
-- Replace the secondary (r:ns)
applyMove nl inst (ReplaceSecondary new_sdx) =
old_s = Container.find old_sdx nl
tgt_n = Container.find new_sdx nl
int_s = Node.removeSec old_s inst
- new_s = Node.addSec tgt_n inst old_pdx
- new_nl = if isNothing(new_s) then Nothing
- else Just $ Container.addTwo new_sdx (fromJust new_s)
- old_sdx int_s nl
- in (new_nl, Instance.setSec inst new_sdx, old_pdx, new_sdx)
+ new_inst = Instance.setSec inst new_sdx
+ new_nl = Node.addSec tgt_n inst old_pdx >>=
+ \new_s -> return (Container.addTwo new_sdx
+ new_s old_sdx int_s nl,
+ new_inst, old_pdx, new_sdx)
+ in new_nl
-- Replace the secondary and failover (r:np, f)
applyMove nl inst (ReplaceAndFailover new_pdx) =
tgt_n = Container.find new_pdx nl
int_p = Node.removePri old_p inst
int_s = Node.removeSec old_s inst
- new_p = Node.addPri tgt_n inst
- new_s = Node.addSec int_p inst new_pdx
- new_nl = if isNothing(new_p) || isNothing(new_s) then Nothing
- else Just $ Container.add new_pdx (fromJust new_p) $
- Container.addTwo old_pdx (fromJust new_s)
- old_sdx int_s nl
- in (new_nl, Instance.setBoth inst new_pdx old_pdx, new_pdx, old_pdx)
+ new_nl = do -- Maybe monad
+ new_p <- Node.addPri tgt_n inst
+ new_s <- Node.addSec int_p inst new_pdx
+ let new_inst = Instance.setBoth inst new_pdx old_pdx
+ return (Container.add new_pdx new_p $
+ Container.addTwo old_pdx new_s old_sdx int_s nl,
+ new_inst, new_pdx, old_pdx)
+ in new_nl
-- Failver and replace the secondary (f, r:ns)
applyMove nl inst (FailoverAndReplace new_sdx) =
tgt_n = Container.find new_sdx nl
int_p = Node.removePri old_p inst
int_s = Node.removeSec old_s inst
- new_p = Node.addPri int_s inst
- new_s = Node.addSec tgt_n inst old_sdx
- new_nl = if isNothing(new_p) || isNothing(new_s) then Nothing
- else Just $ Container.add new_sdx (fromJust new_s) $
- Container.addTwo old_sdx (fromJust new_p)
- old_pdx int_p nl
- in (new_nl, Instance.setBoth inst old_sdx new_sdx, old_sdx, new_sdx)
-
+ new_nl = do -- Maybe monad
+ new_p <- Node.addPri int_s inst
+ new_s <- Node.addSec tgt_n inst old_sdx
+ let new_inst = Instance.setBoth inst old_sdx new_sdx
+ return (Container.add new_sdx new_s $
+ Container.addTwo old_sdx new_p old_pdx int_p nl,
+ new_inst, old_sdx, new_sdx)
+ in new_nl
+
+-- | Tries to allocate an instance on one given node.
+allocateOnSingle :: Node.List -> Instance.Instance -> Node.Node
+ -> OpResult AllocElement
+allocateOnSingle nl inst p =
+ let new_pdx = Node.idx p
+ new_inst = Instance.setBoth inst new_pdx Node.noSecondary
+ new_nl = Node.addPri p inst >>= \new_p ->
+ return (Container.add new_pdx new_p nl, new_inst, [new_p])
+ in new_nl
+
+-- | Tries to allocate an instance on a given pair of nodes.
+allocateOnPair :: Node.List -> Instance.Instance -> Node.Node -> Node.Node
+ -> OpResult AllocElement
+allocateOnPair nl inst tgt_p tgt_s =
+ let new_pdx = Node.idx tgt_p
+ new_sdx = Node.idx tgt_s
+ new_nl = do -- Maybe monad
+ new_p <- Node.addPri tgt_p inst
+ new_s <- Node.addSec tgt_s inst new_pdx
+ let new_inst = Instance.setBoth inst new_pdx new_sdx
+ return (Container.addTwo new_pdx new_p new_sdx new_s nl, new_inst,
+ [new_p, new_s])
+ in new_nl
+
+-- | 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
checkSingleStep ini_tbl target cur_tbl move =
let
Table ini_nl ini_il _ ini_plc = ini_tbl
- (tmp_nl, new_inst, pri_idx, sec_idx) = applyMove ini_nl target move
+ tmp_resu = applyMove ini_nl target move
in
- if isNothing tmp_nl then cur_tbl
- else
- let tgt_idx = Instance.idx target
- upd_nl = fromJust tmp_nl
- upd_cvar = compCV upd_nl
- upd_il = Container.add tgt_idx new_inst ini_il
- upd_plc = (tgt_idx, pri_idx, sec_idx, upd_cvar):ini_plc
- upd_tbl = Table upd_nl upd_il upd_cvar upd_plc
- in
- compareTables cur_tbl upd_tbl
+ case tmp_resu of
+ OpFail _ -> cur_tbl
+ OpGood (upd_nl, new_inst, pri_idx, sec_idx) ->
+ let tgt_idx = Instance.idx target
+ upd_cvar = compCV upd_nl
+ upd_il = Container.add tgt_idx new_inst ini_il
+ upd_plc = (tgt_idx, pri_idx, sec_idx, upd_cvar):ini_plc
+ upd_tbl = Table upd_nl upd_il upd_cvar upd_plc
+ in
+ compareTables cur_tbl upd_tbl
-- | Given the status of the current secondary as a valid new node
-- and the current candidate target node,
-- generate the possible moves for a instance.
-possibleMoves :: Bool -> Int -> [IMove]
+possibleMoves :: Bool -> Ndx -> [IMove]
possibleMoves True tdx =
[ReplaceSecondary tdx,
ReplaceAndFailover tdx,
ReplaceAndFailover tdx]
-- | Compute the best move for a given instance.
-checkInstanceMove :: [Int] -- Allowed target node indices
+checkInstanceMove :: [Ndx] -- Allowed target node indices
-> Table -- Original table
-> Instance.Instance -- Instance to move
-> Table -- Best new table for this instance
foldl' (checkSingleStep ini_tbl target) aft_failover all_moves
-- | Compute the best next move.
-checkMove :: [Int] -- ^ Allowed target node indices
+checkMove :: [Ndx] -- ^ Allowed target node indices
-> Table -- ^ The current solution
-> [Instance.Instance] -- ^ List of instances still to move
-> Table -- ^ The new solution
-- iterate over all instances, computing the best move
best_tbl =
foldl'
- (\ step_tbl elem -> compareTables step_tbl $
- checkInstanceMove nodes_idx ini_tbl elem)
+ (\ step_tbl elem ->
+ if Instance.snode elem == Node.noSecondary then step_tbl
+ else compareTables step_tbl $
+ checkInstanceMove nodes_idx ini_tbl elem)
ini_tbl victims
Table _ _ _ best_plc = best_tbl
in
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 :: NodeList -- ^ 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)
+-- * Allocation functions
+
+-- | Build failure stats out of a list of failures
+collapseFailures :: [FailMode] -> FailStats
+collapseFailures flst =
+ map (\k -> (k, length $ filter ((==) k) flst)) [minBound..maxBound]
+
+-- | Update current Allocation solution and failure stats with new
+-- elements
+concatAllocs :: AllocSolution -> OpResult AllocElement -> AllocSolution
+concatAllocs (flst, succ, sols) (OpFail reason) = (reason:flst, succ, sols)
+
+concatAllocs (flst, succ, osols) (OpGood ns@(nl, _, _)) =
+ let nscore = compCV nl
+ -- Choose the old or new solution, based on the cluster score
+ nsols = case osols of
+ Nothing -> Just (nscore, ns)
+ Just (oscore, _) ->
+ if oscore < nscore
+ then osols
+ else Just (nscore, ns)
+ nsuc = succ + 1
+ -- Note: we force evaluation of nsols here in order to keep the
+ -- memory profile low - we know that we will need nsols for sure
+ -- in the next cycle, so we force evaluation of nsols, since the
+ -- foldl' in the caller will only evaluate the tuple, but not the
+ -- elements of the tuple
+ in nsols `seq` nsuc `seq` (flst, nsuc, nsols)
+
+-- | 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 AllocSolution -- ^ 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 = foldl' (\cstate (p, s) ->
+ concatAllocs cstate $ allocateOnPair nl inst p s
+ ) ([], 0, Nothing) ok_pairs
+ in return sols
+
+tryAlloc nl _ inst 1 =
+ let all_nodes = getOnline nl
+ sols = foldl' (\cstate p ->
+ concatAllocs cstate $ allocateOnSingle nl inst p
+ ) ([], 0, Nothing) all_nodes
+ in return sols
+
+tryAlloc _ _ _ reqn = fail $ "Unsupported number of allocation \
+ \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 number of nodes required
+ -> [Ndx] -- ^ Nodes which should not be used
+ -> m AllocSolution -- ^ 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 = foldl' (\cstate x ->
+ let elem = do
+ (mnl, i, _, _) <-
+ applyMove nl inst (ReplaceSecondary x)
+ return (mnl, i, [Container.find x mnl])
+ in concatAllocs cstate elem
+ ) ([], 0, Nothing) 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
-- either @/f/@ for failover or @/r:name/@ for replace
-- secondary, while the command list holds gnt-instance
-- commands (without that prefix), e.g \"@failover instance1@\"
-computeMoves i a b c d =
- if c == a then {- Same primary -}
- if d == b then {- Same sec??! -}
- ("-", [])
+computeMoves i a b c d
+ -- same primary
+ | c == a =
+ if d == b
+ then {- Same sec??! -} ("-", [])
else {- Change of secondary -}
- (printf "r:%s" d,
- [printf "replace-disks -n %s %s" d i])
- else
- if c == b then {- Failover and ... -}
- if d == a then {- that's all -}
- ("f", [printf "migrate %s" i])
- else
- (printf "f r:%s" d,
- [printf "migrate %s" i,
- printf "replace-disks -n %s %s" d i])
- else
- if d == a then {- ... and keep primary as secondary -}
- (printf "r:%s f" c,
- [printf "replace-disks -n %s %s" c i,
- printf "migrate %s" i])
- else
- if d == b then {- ... keep same secondary -}
- (printf "f r:%s f" c,
- [printf "migrate %s" i,
- printf "replace-disks -n %s %s" c i,
- printf "migrate %s" i])
-
- else {- Nothing in common -}
- (printf "r:%s f r:%s" c d,
- [printf "replace-disks -n %s %s" c i,
- printf "migrate %s" i,
- printf "replace-disks -n %s %s" d i])
-
-{-| Converts a placement to string format -}
-printSolutionLine :: InstanceList
- -> NameList
- -> NameList
- -> Int
- -> Int
- -> Placement
- -> Int
- -> (String, [String])
-printSolutionLine il ktn kti nmlen imlen plc pos =
+ (printf "r:%s" d, [rep d])
+ -- failover and ...
+ | c == b =
+ if d == a
+ then {- that's all -} ("f", [mig])
+ else (printf "f r:%s" d, [mig, rep d])
+ -- ... and keep primary as secondary
+ | d == a =
+ (printf "r:%s f" c, [rep c, mig])
+ -- ... keep same secondary
+ | d == b =
+ (printf "f r:%s f" c, [mig, rep c, mig])
+ -- nothing in common -
+ | otherwise =
+ (printf "r:%s f r:%s" c d, [rep c, mig, rep d])
+ where mig = printf "migrate -f %s" i::String
+ rep n = printf "replace-disks -n %s %s" n i
+
+-- | 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 = (2*nmlen + 1)
(i, p, s, c) = plc
inst = Container.find i il
- inam = fromJust $ lookup (Instance.idx inst) kti
- npri = fromJust $ lookup p ktn
- nsec = fromJust $ lookup s ktn
- opri = fromJust $ lookup (Instance.pnode inst) ktn
- osec = fromJust $ lookup (Instance.snode inst) ktn
+ inam = Instance.name inst
+ npri = Container.nameOf nl p
+ nsec = Container.nameOf nl s
+ opri = Container.nameOf nl $ Instance.pnode inst
+ osec = Container.nameOf nl $ Instance.snode inst
(moves, cmds) = computeMoves inam opri osec npri nsec
- ostr = (printf "%s:%s" opri osec)::String
- nstr = (printf "%s:%s" npri nsec)::String
+ ostr = printf "%s:%s" opri osec::String
+ nstr = printf "%s:%s" npri nsec::String
in
(printf " %3d. %-*s %-*s => %-*s %.8f a=%s"
pos imlen inam pmlen ostr
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 (" echo " ++) $
- concat $ map (\(a, b) ->
- (printf "step %d" (a::Int)):(map ("gnt-instance " ++) b)) $
- zip [1..] cmd_strs
-
-{-| Converts a solution to string format -}
-printSolution :: InstanceList
- -> NameList
- -> NameList
+formatCmds =
+ unlines .
+ concatMap (\(a, b) ->
+ printf "echo step %d" (a::Int):
+ printf "check":
+ map ("gnt-instance " ++) b
+ ) .
+ zip [1..]
+
+-- | Converts a solution to string format.
+printSolution :: Node.List
+ -> Instance.List
-> [Placement]
-> ([String], [[String]])
-printSolution il ktn kti sol =
+printSolution nl il sol =
let
- mlen_fn = maximum . (map length) . snd . unzip
- imlen = mlen_fn kti
- nmlen = mlen_fn ktn
+ nmlen = Container.maxNameLen nl
+ imlen = Container.maxNameLen il
in
- unzip $ map (uncurry $ printSolutionLine il ktn kti nmlen imlen) $
- zip sol [1..]
+ unzip $ zipWith (printSolutionLine nl il nmlen imlen) sol [1..]
-- | Print the node list.
-printNodes :: NameList -> NodeList -> String
-printNodes ktn nl =
+printNodes :: Node.List -> String
+printNodes nl =
let snl = sortBy (compare `on` Node.idx) (Container.elems nl)
- snl' = map (\ n -> ((fromJust $ lookup (Node.idx n) ktn), n)) snl
- m_name = maximum . (map length) . fst . unzip $ snl'
+ m_name = maximum . map (length . Node.name) $ snl
helper = Node.list m_name
- header = printf "%2s %-*s %5s %5s %5s %5s %5s %3s %3s %7s %7s"
- " F" m_name "Name" "t_mem" "f_mem" "r_mem"
- "t_dsk" "f_dsk"
- "pri" "sec" "p_fmem" "p_fdsk"
- in unlines $ (header:map (uncurry helper) snl')
-
--- | Compute the mem and disk covariance.
-compDetailedCV :: NodeList -> (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 :: NodeList -> 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
-
-printStats :: NodeList -> String
+ header = printf
+ "%2s %-*s %5s %5s %5s %5s %5s %5s %5s %5s %4s %4s \
+ \%3s %3s %6s %6s %5s"
+ " F" m_name "Name"
+ "t_mem" "n_mem" "i_mem" "x_mem" "f_mem" "r_mem"
+ "t_dsk" "f_dsk" "pcpu" "vcpu"
+ "pri" "sec" "p_fmem" "p_fdsk" "r_cpu"::String
+ in unlines (header:map helper snl)
+
+-- | 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
- in printf "f_mem=%.8f, r_mem=%.8f, f_dsk=%.8f, n1=%.3f, uf=%.3f"
- mem_cv res_cv dsk_cv n1_score off_score
-
--- Balancing functions
-
--- Loading functions
-
-{- | Convert newline and delimiter-separated text.
-
-This function converts a text in tabular format as generated by
-@gnt-instance list@ and @gnt-node list@ to a list of objects using a
-supplied conversion function.
-
--}
-loadTabular :: String -> ([String] -> (String, a))
- -> (a -> Int -> a) -> ([(String, Int)], [(Int, a)])
-loadTabular text_data convert_fn set_fn =
- let lines_data = lines text_data
- rows = map (sepSplit '|') lines_data
- kerows = (map convert_fn rows)
- idxrows = map (\ (idx, (k, v)) -> ((k, idx), (idx, set_fn v idx)))
- (zip [0..] kerows)
- in unzip idxrows
-
--- | For each instance, add its index to its primary and secondary nodes
-fixNodes :: [(Int, Node.Node)]
- -> [(Int, Instance.Instance)]
- -> [(Int, Node.Node)]
-fixNodes nl il =
- foldl' (\accu (idx, inst) ->
- let
- assocEqual = (\ (i, _) (j, _) -> i == j)
- pdx = Instance.pnode inst
- sdx = Instance.snode inst
- pold = fromJust $ lookup pdx accu
- sold = fromJust $ lookup sdx accu
- pnew = Node.setPri pold idx
- snew = Node.setSec sold idx
- ac1 = deleteBy assocEqual (pdx, pold) accu
- ac2 = deleteBy assocEqual (sdx, sold) ac1
- ac3 = (pdx, pnew):(sdx, snew):ac2
- in ac3) nl il
-
--- | Compute the longest common suffix of a NameList list that
--- | starts with a dot
-longestDomain :: NameList -> String
-longestDomain [] = ""
-longestDomain ((_,x):xs) =
- let
- onlyStrings = snd $ unzip xs
- in
- foldr (\ suffix accu -> if all (isSuffixOf suffix) onlyStrings
- then suffix
- else accu)
- "" $ filter (isPrefixOf ".") (tails x)
-
--- | Remove tails from the (Int, String) lists
-stripSuffix :: String -> NameList -> NameList
-stripSuffix suffix lst =
- let sflen = length suffix in
- map (\ (key, name) -> (key, take ((length name) - sflen) name)) lst
-
-{-| Initializer function that loads the data from a node and list file
- and massages it into the correct format. -}
-loadData :: String -- ^ Node data in text format
- -> String -- ^ Instance data in text format
- -> (Container.Container Node.Node,
- Container.Container Instance.Instance,
- String, NameList, NameList)
-loadData ndata idata =
- let
- {- node file: name t_mem f_mem t_disk f_disk -}
- (ktn, nl) = loadTabular ndata
- (\ (name:tm:fm:td:fd:[]) ->
- (name,
- Node.create (read tm) (read fm) (read td) (read fd)))
- Node.setIdx
- {- instance file: name mem disk pnode snode -}
- (kti, il) = loadTabular idata
- (\ (name:mem:dsk:pnode:snode:[]) ->
- (name,
- Instance.create (read mem) (read dsk)
- (fromJust $ lookup pnode ktn)
- (fromJust $ lookup snode ktn)))
- Instance.setIdx
- nl2 = fixNodes nl il
- il3 = Container.fromAssocList il
- nl3 = Container.fromAssocList
- (map (\ (k, v) -> (k, Node.buildPeers v il3 (length nl2))) nl2)
- xtn = swapPairs ktn
- xti = swapPairs kti
- common_suffix = longestDomain (xti ++ xtn)
- stn = stripSuffix common_suffix xtn
- sti = stripSuffix common_suffix xti
- in
- (nl3, il3, common_suffix, stn, sti)
+ let (mem_cv, dsk_cv, n1_score, res_cv, off_score, cpu_cv) =
+ compDetailedCV nl
+ in printf "f_mem=%.8f, r_mem=%.8f, f_dsk=%.8f, n1=%.3f, \
+ \uf=%.3f, r_cpu=%.3f"
+ mem_cv res_cv dsk_cv n1_score off_score cpu_cv
projects / ganeti-local / blobdiff