## root / Ganeti / HTools / Cluster.hs @ 9d3fada5

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{-| Implementation of cluster-wide logic. |
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This module holds all pure cluster-logic; I\/O related functionality |

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goes into the "Main" module for the individual binaries. |

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-} |

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module Ganeti.HTools.Cluster |

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( |

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-- * Types |

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NodeList |

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, InstanceList |

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, NameList |

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, Placement |

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, Solution(..) |

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, Table(..) |

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, Removal |

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, Score |

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-- * Generic functions |

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, totalResources |

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-- * First phase functions |

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, computeBadItems |

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-- * Second phase functions |

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, computeSolution |

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, applySolution |

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, printSolution |

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, printSolutionLine |

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, formatCmds |

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, printNodes |

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-- * Balacing functions |

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, checkMove |

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, compCV |

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, printStats |

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-- * Loading functions |

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, loadData |

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, checkData |

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) where |

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import Data.List |

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import Data.Maybe (isNothing, fromJust) |

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import Text.Printf (printf) |

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import Data.Function |

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import Control.Monad |

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import qualified Ganeti.HTools.Container as Container |

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import qualified Ganeti.HTools.Instance as Instance |

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import qualified Ganeti.HTools.Node as Node |

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import Ganeti.HTools.Utils |

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type NodeList = Container.Container Node.Node |

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type InstanceList = Container.Container Instance.Instance |

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-- | The type used to hold idx-to-name mappings |

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type NameList = [(Int, String)] |

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-- | A separate name for the cluster score type |

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type Score = Double |

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-- | The description of an instance placement. |

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type Placement = (Int, Int, Int, Score) |

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{- | A cluster solution described as the solution delta and the list |

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of placements. |

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-} |

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data Solution = Solution Int [Placement] |

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deriving (Eq, Ord, Show) |

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-- | Returns the delta of a solution or -1 for Nothing |

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solutionDelta :: Maybe Solution -> Int |

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solutionDelta sol = case sol of |

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Just (Solution d _) -> d |

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_ -> -1 |

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-- | A removal set. |

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data Removal = Removal NodeList [Instance.Instance] |

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-- | An instance move definition |

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data IMove = Failover -- ^ Failover the instance (f) |

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| ReplacePrimary Int -- ^ Replace primary (f, r:np, f) |

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| ReplaceSecondary Int -- ^ Replace secondary (r:ns) |

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| ReplaceAndFailover Int -- ^ Replace secondary, failover (r:np, f) |

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| FailoverAndReplace Int -- ^ Failover, replace secondary (f, r:ns) |

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deriving (Show) |

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-- | The complete state for the balancing solution |

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data Table = Table NodeList InstanceList Score [Placement] |

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deriving (Show) |

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-- General functions |

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-- | Cap the removal list if needed. |

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capRemovals :: [a] -> Int -> [a] |

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capRemovals removals max_removals = |

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if max_removals > 0 then |

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take max_removals removals |

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else |

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removals |

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-- | Check if the given node list fails the N+1 check. |

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verifyN1Check :: [Node.Node] -> Bool |

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verifyN1Check nl = any Node.failN1 nl |

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-- | Verifies the N+1 status and return the affected nodes. |

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verifyN1 :: [Node.Node] -> [Node.Node] |

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verifyN1 nl = filter Node.failN1 nl |

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{-| Add an instance and return the new node and instance maps. -} |

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addInstance :: NodeList -> Instance.Instance -> |

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Node.Node -> Node.Node -> Maybe NodeList |

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addInstance nl idata pri sec = |

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let pdx = Node.idx pri |

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sdx = Node.idx sec |

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in do |

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pnode <- Node.addPri pri idata |

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snode <- Node.addSec sec idata pdx |

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new_nl <- return $ Container.addTwo sdx snode |

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pdx pnode nl |

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return new_nl |

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-- | Remove an instance and return the new node and instance maps. |

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removeInstance :: NodeList -> Instance.Instance -> NodeList |

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removeInstance nl idata = |

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let pnode = Instance.pnode idata |

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snode = Instance.snode idata |

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pn = Container.find pnode nl |

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sn = Container.find snode nl |

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new_nl = Container.addTwo |

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pnode (Node.removePri pn idata) |

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snode (Node.removeSec sn idata) nl in |

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new_nl |

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-- | Remove an instance and return the new node map. |

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removeInstances :: NodeList -> [Instance.Instance] -> NodeList |

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removeInstances = foldl' removeInstance |

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-- | Compute the total free disk and memory in the cluster. |

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totalResources :: Container.Container Node.Node -> (Int, Int) |

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totalResources nl = |

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foldl' |

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(\ (mem, dsk) node -> (mem + (Node.f_mem node), |

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dsk + (Node.f_dsk node))) |

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(0, 0) (Container.elems nl) |

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{- | Compute a new version of a cluster given a solution. |

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This is not used for computing the solutions, but for applying a |

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(known-good) solution to the original cluster for final display. |

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It first removes the relocated instances after which it places them on |

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their new nodes. |

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-} |

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applySolution :: NodeList -> InstanceList -> [Placement] -> NodeList |

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applySolution nl il sol = |

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let odxes = map (\ (a, b, c, _) -> (Container.find a il, |

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Node.idx (Container.find b nl), |

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Node.idx (Container.find c nl)) |

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) sol |

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idxes = (\ (x, _, _) -> x) (unzip3 odxes) |

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nc = removeInstances nl idxes |

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in |

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foldl' (\ nz (a, b, c) -> |

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let new_p = Container.find b nz |

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new_s = Container.find c nz in |

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fromJust (addInstance nz a new_p new_s) |

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) nc odxes |

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-- First phase functions |

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{- | Given a list 1,2,3..n build a list of pairs [(1, [2..n]), (2, |

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[3..n]), ...] |

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-} |

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genParts :: [a] -> Int -> [(a, [a])] |

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genParts l count = |

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case l of |

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[] -> [] |

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x:xs -> |

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if length l < count then |

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[] |

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else |

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(x, xs) : (genParts xs count) |

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-- | Generates combinations of count items from the names list. |

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genNames :: Int -> [b] -> [[b]] |

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genNames count1 names1 = |

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let aux_fn count names current = |

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case count of |

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0 -> [current] |

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_ -> |

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concatMap |

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(\ (x, xs) -> aux_fn (count - 1) xs (x:current)) |

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(genParts names count) |

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in |

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aux_fn count1 names1 [] |

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{- | Computes the pair of bad nodes and instances. |

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The bad node list is computed via a simple 'verifyN1' check, and the |

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bad instance list is the list of primary and secondary instances of |

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those nodes. |

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-} |

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computeBadItems :: NodeList -> InstanceList -> |

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([Node.Node], [Instance.Instance]) |

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computeBadItems nl il = |

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let bad_nodes = verifyN1 $ filter (not . Node.offline) $ Container.elems nl |

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bad_instances = map (\idx -> Container.find idx il) $ |

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sort $ nub $ concat $ |

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map (\ n -> (Node.slist n) ++ (Node.plist n)) bad_nodes |

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in |

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(bad_nodes, bad_instances) |

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{- | Checks if removal of instances results in N+1 pass. |

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Note: the check removal cannot optimize by scanning only the affected |

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nodes, since the cluster is known to be not healthy; only the check |

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placement can make this shortcut. |

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-} |

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checkRemoval :: NodeList -> [Instance.Instance] -> Maybe Removal |

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checkRemoval nl victims = |

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let nx = removeInstances nl victims |

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failN1 = verifyN1Check (Container.elems nx) |

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in |

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if failN1 then |

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Nothing |

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else |

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Just $ Removal nx victims |

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-- | Computes the removals list for a given depth |

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computeRemovals :: NodeList |

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-> [Instance.Instance] |

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-> Int |

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-> [Maybe Removal] |

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computeRemovals nl bad_instances depth = |

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map (checkRemoval nl) $ genNames depth bad_instances |

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-- Second phase functions |

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-- | Single-node relocation cost |

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nodeDelta :: Int -> Int -> Int -> Int |

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nodeDelta i p s = |

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if i == p || i == s then |

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0 |

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else |

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1 |

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{-| Compute best solution. |

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This function compares two solutions, choosing the minimum valid |

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solution. |

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-} |

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compareSolutions :: Maybe Solution -> Maybe Solution -> Maybe Solution |

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compareSolutions a b = case (a, b) of |

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(Nothing, x) -> x |

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(x, Nothing) -> x |

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(x, y) -> min x y |

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-- | Compute best table. Note that the ordering of the arguments is important. |

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compareTables :: Table -> Table -> Table |

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compareTables a@(Table _ _ a_cv _) b@(Table _ _ b_cv _ ) = |

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if a_cv > b_cv then b else a |

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-- | Check if a given delta is worse then an existing solution. |

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tooHighDelta :: Maybe Solution -> Int -> Int -> Bool |

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tooHighDelta sol new_delta max_delta = |

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if new_delta > max_delta && max_delta >=0 then |

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True |

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else |

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case sol of |

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Nothing -> False |

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Just (Solution old_delta _) -> old_delta <= new_delta |

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{-| Check if placement of instances still keeps the cluster N+1 compliant. |

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This is the workhorse of the allocation algorithm: given the |

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current node and instance maps, the list of instances to be |

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placed, and the current solution, this will return all possible |

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solution by recursing until all target instances are placed. |

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-} |

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checkPlacement :: NodeList -- ^ The current node list |

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-> [Instance.Instance] -- ^ List of instances still to place |

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-> [Placement] -- ^ Partial solution until now |

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-> Int -- ^ The delta of the partial solution |

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-> Maybe Solution -- ^ The previous solution |

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-> Int -- ^ Abort if the we go above this delta |

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-> Maybe Solution -- ^ The new solution |

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checkPlacement nl victims current current_delta prev_sol max_delta = |

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let target = head victims |

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opdx = Instance.pnode target |

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osdx = Instance.snode target |

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vtail = tail victims |

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have_tail = (length vtail) > 0 |

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nodes = Container.elems nl |

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iidx = Instance.idx target |

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in |

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foldl' |

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(\ accu_p pri -> |

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let |

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pri_idx = Node.idx pri |

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upri_delta = current_delta + nodeDelta pri_idx opdx osdx |

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new_pri = Node.addPri pri target |

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fail_delta1 = tooHighDelta accu_p upri_delta max_delta |

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in |

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if fail_delta1 || isNothing(new_pri) then accu_p |

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else let pri_nl = Container.add pri_idx (fromJust new_pri) nl in |

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foldl' |

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(\ accu sec -> |

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let |

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sec_idx = Node.idx sec |

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upd_delta = upri_delta + |

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nodeDelta sec_idx opdx osdx |

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fail_delta2 = tooHighDelta accu upd_delta max_delta |

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new_sec = Node.addSec sec target pri_idx |

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in |

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if sec_idx == pri_idx || fail_delta2 || |

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isNothing new_sec then accu |

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else let |

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nx = Container.add sec_idx (fromJust new_sec) pri_nl |

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upd_cv = compCV nx |

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plc = (iidx, pri_idx, sec_idx, upd_cv) |

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c2 = plc:current |

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result = |

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if have_tail then |

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checkPlacement nx vtail c2 upd_delta |

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accu max_delta |

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else |

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Just (Solution upd_delta c2) |

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in compareSolutions accu result |

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) accu_p nodes |

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) prev_sol nodes |

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-- | Apply a move |

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applyMove :: NodeList -> Instance.Instance |

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-> IMove -> (Maybe NodeList, Instance.Instance, Int, Int) |

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-- Failover (f) |

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applyMove nl inst Failover = |

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let old_pdx = Instance.pnode inst |

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old_sdx = Instance.snode inst |

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old_p = Container.find old_pdx nl |

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old_s = Container.find old_sdx nl |

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int_p = Node.removePri old_p inst |

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int_s = Node.removeSec old_s inst |

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new_nl = do -- Maybe monad |

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new_p <- Node.addPri int_s inst |

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new_s <- Node.addSec int_p inst old_sdx |

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return $ Container.addTwo old_pdx new_s old_sdx new_p nl |

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in (new_nl, Instance.setBoth inst old_sdx old_pdx, old_sdx, old_pdx) |

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-- Replace the primary (f:, r:np, f) |

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applyMove nl inst (ReplacePrimary new_pdx) = |

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let old_pdx = Instance.pnode inst |

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old_sdx = Instance.snode inst |

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old_p = Container.find old_pdx nl |

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old_s = Container.find old_sdx nl |

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tgt_n = Container.find new_pdx nl |

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int_p = Node.removePri old_p inst |

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int_s = Node.removeSec old_s inst |

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new_nl = do -- Maybe monad |

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new_p <- Node.addPri tgt_n inst |

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new_s <- Node.addSec int_s inst new_pdx |

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return $ Container.add new_pdx new_p $ |

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Container.addTwo old_pdx int_p old_sdx new_s nl |

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in (new_nl, Instance.setPri inst new_pdx, new_pdx, old_sdx) |

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-- Replace the secondary (r:ns) |

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applyMove nl inst (ReplaceSecondary new_sdx) = |

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let old_pdx = Instance.pnode inst |

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old_sdx = Instance.snode inst |

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old_s = Container.find old_sdx nl |

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tgt_n = Container.find new_sdx nl |

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int_s = Node.removeSec old_s inst |

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new_nl = Node.addSec tgt_n inst old_pdx >>= |

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\new_s -> return $ Container.addTwo new_sdx |

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new_s old_sdx int_s nl |

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in (new_nl, Instance.setSec inst new_sdx, old_pdx, new_sdx) |

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-- Replace the secondary and failover (r:np, f) |

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applyMove nl inst (ReplaceAndFailover new_pdx) = |

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let old_pdx = Instance.pnode inst |

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old_sdx = Instance.snode inst |

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old_p = Container.find old_pdx nl |

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old_s = Container.find old_sdx nl |

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tgt_n = Container.find new_pdx nl |

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int_p = Node.removePri old_p inst |

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int_s = Node.removeSec old_s inst |

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new_nl = do -- Maybe monad |

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new_p <- Node.addPri tgt_n inst |

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new_s <- Node.addSec int_p inst new_pdx |

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return $ Container.add new_pdx new_p $ |

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Container.addTwo old_pdx new_s old_sdx int_s nl |

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in (new_nl, Instance.setBoth inst new_pdx old_pdx, new_pdx, old_pdx) |

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-- Failver and replace the secondary (f, r:ns) |

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applyMove nl inst (FailoverAndReplace new_sdx) = |

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let old_pdx = Instance.pnode inst |

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old_sdx = Instance.snode inst |

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old_p = Container.find old_pdx nl |

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old_s = Container.find old_sdx nl |

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tgt_n = Container.find new_sdx nl |

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int_p = Node.removePri old_p inst |

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int_s = Node.removeSec old_s inst |

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new_nl = do -- Maybe monad |

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new_p <- Node.addPri int_s inst |

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new_s <- Node.addSec tgt_n inst old_sdx |

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return $ Container.add new_sdx new_s $ |

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Container.addTwo old_sdx new_p old_pdx int_p nl |

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in (new_nl, Instance.setBoth inst old_sdx new_sdx, old_sdx, new_sdx) |

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checkSingleStep :: Table -- ^ The original table |

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-> Instance.Instance -- ^ The instance to move |

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-> Table -- ^ The current best table |

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-> IMove -- ^ The move to apply |

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-> Table -- ^ The final best table |

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checkSingleStep ini_tbl target cur_tbl move = |

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let |

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Table ini_nl ini_il _ ini_plc = ini_tbl |

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(tmp_nl, new_inst, pri_idx, sec_idx) = applyMove ini_nl target move |

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in |

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if isNothing tmp_nl then cur_tbl |

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else |

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let tgt_idx = Instance.idx target |

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upd_nl = fromJust tmp_nl |

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upd_cvar = compCV upd_nl |

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upd_il = Container.add tgt_idx new_inst ini_il |

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upd_plc = (tgt_idx, pri_idx, sec_idx, upd_cvar):ini_plc |

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upd_tbl = Table upd_nl upd_il upd_cvar upd_plc |

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in |

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compareTables cur_tbl upd_tbl |

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-- | Given the status of the current secondary as a valid new node |

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-- and the current candidate target node, |

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-- generate the possible moves for a instance. |

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possibleMoves :: Bool -> Int -> [IMove] |

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possibleMoves True tdx = |

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[ReplaceSecondary tdx, |

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ReplaceAndFailover tdx, |

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ReplacePrimary tdx, |

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FailoverAndReplace tdx] |

444 | |

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possibleMoves False tdx = |

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[ReplaceSecondary tdx, |

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ReplaceAndFailover tdx] |

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-- | Compute the best move for a given instance. |

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checkInstanceMove :: [Int] -- Allowed target node indices |

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-> Table -- Original table |

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-> Instance.Instance -- Instance to move |

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-> Table -- Best new table for this instance |

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checkInstanceMove nodes_idx ini_tbl target = |

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let |

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opdx = Instance.pnode target |

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osdx = Instance.snode target |

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nodes = filter (\idx -> idx /= opdx && idx /= osdx) nodes_idx |

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use_secondary = elem osdx nodes_idx |

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aft_failover = if use_secondary -- if allowed to failover |

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then checkSingleStep ini_tbl target ini_tbl Failover |

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else ini_tbl |

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all_moves = concatMap (possibleMoves use_secondary) nodes |

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in |

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-- iterate over the possible nodes for this instance |

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foldl' (checkSingleStep ini_tbl target) aft_failover all_moves |

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-- | Compute the best next move. |

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checkMove :: [Int] -- ^ Allowed target node indices |

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-> Table -- ^ The current solution |

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-> [Instance.Instance] -- ^ List of instances still to move |

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-> Table -- ^ The new solution |

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checkMove nodes_idx ini_tbl victims = |

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let Table _ _ _ ini_plc = ini_tbl |

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-- iterate over all instances, computing the best move |

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best_tbl = |

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foldl' |

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(\ step_tbl elem -> compareTables step_tbl $ |

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checkInstanceMove nodes_idx ini_tbl elem) |

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ini_tbl victims |

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Table _ _ _ best_plc = best_tbl |

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in |

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if length best_plc == length ini_plc then -- no advancement |

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ini_tbl |

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else |

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best_tbl |

487 | |

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{- | Auxiliary function for solution computation. |

489 | |

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We write this in an explicit recursive fashion in order to control |

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early-abort in case we have met the min delta. We can't use foldr |

492 |
instead of explicit recursion since we need the accumulator for the |

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abort decision. |

494 | |

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-} |

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advanceSolution :: [Maybe Removal] -- ^ The removal to process |

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-> Int -- ^ Minimum delta parameter |

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-> Int -- ^ Maximum delta parameter |

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-> Maybe Solution -- ^ Current best solution |

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-> Maybe Solution -- ^ New best solution |

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advanceSolution [] _ _ sol = sol |

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advanceSolution (Nothing:xs) m n sol = advanceSolution xs m n sol |

503 |
advanceSolution ((Just (Removal nx removed)):xs) min_d max_d prev_sol = |

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let new_sol = checkPlacement nx removed [] 0 prev_sol max_d |

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new_delta = solutionDelta $! new_sol |

506 |
in |

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if new_delta >= 0 && new_delta <= min_d then |

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new_sol |

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else |

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advanceSolution xs min_d max_d new_sol |

511 | |

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-- | Computes the placement solution. |

513 |
solutionFromRemovals :: [Maybe Removal] -- ^ The list of (possible) removals |

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-> Int -- ^ Minimum delta parameter |

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-> Int -- ^ Maximum delta parameter |

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-> Maybe Solution -- ^ The best solution found |

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solutionFromRemovals removals min_delta max_delta = |

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advanceSolution removals min_delta max_delta Nothing |

519 | |

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{- | Computes the solution at the given depth. |

521 | |

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This is a wrapper over both computeRemovals and |

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solutionFromRemovals. In case we have no solution, we return Nothing. |

524 | |

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-} |

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computeSolution :: NodeList -- ^ The original node data |

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-> [Instance.Instance] -- ^ The list of /bad/ instances |

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-> Int -- ^ The /depth/ of removals |

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-> Int -- ^ Maximum number of removals to process |

530 |
-> Int -- ^ Minimum delta parameter |

531 |
-> Int -- ^ Maximum delta parameter |

532 |
-> Maybe Solution -- ^ The best solution found (or Nothing) |

533 |
computeSolution nl bad_instances depth max_removals min_delta max_delta = |

534 |
let |

535 |
removals = computeRemovals nl bad_instances depth |

536 |
removals' = capRemovals removals max_removals |

537 |
in |

538 |
solutionFromRemovals removals' min_delta max_delta |

539 | |

540 |
-- Solution display functions (pure) |

541 | |

542 |
-- | Given the original and final nodes, computes the relocation description. |

543 |
computeMoves :: String -- ^ The instance name |

544 |
-> String -- ^ Original primary |

545 |
-> String -- ^ Original secondary |

546 |
-> String -- ^ New primary |

547 |
-> String -- ^ New secondary |

548 |
-> (String, [String]) |

549 |
-- ^ Tuple of moves and commands list; moves is containing |

550 |
-- either @/f/@ for failover or @/r:name/@ for replace |

551 |
-- secondary, while the command list holds gnt-instance |

552 |
-- commands (without that prefix), e.g \"@failover instance1@\" |

553 |
computeMoves i a b c d = |

554 |
if c == a then {- Same primary -} |

555 |
if d == b then {- Same sec??! -} |

556 |
("-", []) |

557 |
else {- Change of secondary -} |

558 |
(printf "r:%s" d, |

559 |
[printf "replace-disks -n %s %s" d i]) |

560 |
else |

561 |
if c == b then {- Failover and ... -} |

562 |
if d == a then {- that's all -} |

563 |
("f", [printf "migrate -f %s" i]) |

564 |
else |

565 |
(printf "f r:%s" d, |

566 |
[printf "migrate -f %s" i, |

567 |
printf "replace-disks -n %s %s" d i]) |

568 |
else |

569 |
if d == a then {- ... and keep primary as secondary -} |

570 |
(printf "r:%s f" c, |

571 |
[printf "replace-disks -n %s %s" c i, |

572 |
printf "migrate -f %s" i]) |

573 |
else |

574 |
if d == b then {- ... keep same secondary -} |

575 |
(printf "f r:%s f" c, |

576 |
[printf "migrate -f %s" i, |

577 |
printf "replace-disks -n %s %s" c i, |

578 |
printf "migrate -f %s" i]) |

579 | |

580 |
else {- Nothing in common -} |

581 |
(printf "r:%s f r:%s" c d, |

582 |
[printf "replace-disks -n %s %s" c i, |

583 |
printf "migrate -f %s" i, |

584 |
printf "replace-disks -n %s %s" d i]) |

585 | |

586 |
{-| Converts a placement to string format -} |

587 |
printSolutionLine :: InstanceList |

588 |
-> NameList |

589 |
-> NameList |

590 |
-> Int |

591 |
-> Int |

592 |
-> Placement |

593 |
-> Int |

594 |
-> (String, [String]) |

595 |
printSolutionLine il ktn kti nmlen imlen plc pos = |

596 |
let |

597 |
pmlen = (2*nmlen + 1) |

598 |
(i, p, s, c) = plc |

599 |
inst = Container.find i il |

600 |
inam = fromJust $ lookup (Instance.idx inst) kti |

601 |
npri = fromJust $ lookup p ktn |

602 |
nsec = fromJust $ lookup s ktn |

603 |
opri = fromJust $ lookup (Instance.pnode inst) ktn |

604 |
osec = fromJust $ lookup (Instance.snode inst) ktn |

605 |
(moves, cmds) = computeMoves inam opri osec npri nsec |

606 |
ostr = (printf "%s:%s" opri osec)::String |

607 |
nstr = (printf "%s:%s" npri nsec)::String |

608 |
in |

609 |
(printf " %3d. %-*s %-*s => %-*s %.8f a=%s" |

610 |
pos imlen inam pmlen ostr |

611 |
pmlen nstr c moves, |

612 |
cmds) |

613 | |

614 |
formatCmds :: [[String]] -> String |

615 |
formatCmds cmd_strs = |

616 |
unlines $ |

617 |
concat $ map (\(a, b) -> |

618 |
(printf "echo step %d" (a::Int)): |

619 |
(printf "check"): |

620 |
(map ("gnt-instance " ++) b)) $ |

621 |
zip [1..] cmd_strs |

622 | |

623 |
{-| Converts a solution to string format -} |

624 |
printSolution :: InstanceList |

625 |
-> NameList |

626 |
-> NameList |

627 |
-> [Placement] |

628 |
-> ([String], [[String]]) |

629 |
printSolution il ktn kti sol = |

630 |
let |

631 |
mlen_fn = maximum . (map length) . snd . unzip |

632 |
imlen = mlen_fn kti |

633 |
nmlen = mlen_fn ktn |

634 |
in |

635 |
unzip $ map (uncurry $ printSolutionLine il ktn kti nmlen imlen) $ |

636 |
zip sol [1..] |

637 | |

638 |
-- | Print the node list. |

639 |
printNodes :: NameList -> NodeList -> String |

640 |
printNodes ktn nl = |

641 |
let snl = sortBy (compare `on` Node.idx) (Container.elems nl) |

642 |
snl' = map (\ n -> ((fromJust $ lookup (Node.idx n) ktn), n)) snl |

643 |
m_name = maximum . (map length) . fst . unzip $ snl' |

644 |
helper = Node.list m_name |

645 |
header = printf |

646 |
"%2s %-*s %5s %5s %5s %5s %5s %5s %5s %5s %3s %3s %7s %7s" |

647 |
" F" m_name "Name" |

648 |
"t_mem" "n_mem" "i_mem" "x_mem" "f_mem" "r_mem" |

649 |
"t_dsk" "f_dsk" |

650 |
"pri" "sec" "p_fmem" "p_fdsk" |

651 |
in unlines $ (header:map (uncurry helper) snl') |

652 | |

653 |
-- | Compute the mem and disk covariance. |

654 |
compDetailedCV :: NodeList -> (Double, Double, Double, Double, Double) |

655 |
compDetailedCV nl = |

656 |
let |

657 |
all_nodes = Container.elems nl |

658 |
(offline, nodes) = partition Node.offline all_nodes |

659 |
mem_l = map Node.p_mem nodes |

660 |
dsk_l = map Node.p_dsk nodes |

661 |
mem_cv = varianceCoeff mem_l |

662 |
dsk_cv = varianceCoeff dsk_l |

663 |
n1_l = length $ filter Node.failN1 nodes |

664 |
n1_score = (fromIntegral n1_l) / (fromIntegral $ length nodes) |

665 |
res_l = map Node.p_rem nodes |

666 |
res_cv = varianceCoeff res_l |

667 |
offline_inst = sum . map (\n -> (length . Node.plist $ n) + |

668 |
(length . Node.slist $ n)) $ offline |

669 |
online_inst = sum . map (\n -> (length . Node.plist $ n) + |

670 |
(length . Node.slist $ n)) $ nodes |

671 |
off_score = (fromIntegral offline_inst) / |

672 |
(fromIntegral $ online_inst + offline_inst) |

673 |
in (mem_cv, dsk_cv, n1_score, res_cv, off_score) |

674 | |

675 |
-- | Compute the 'total' variance. |

676 |
compCV :: NodeList -> Double |

677 |
compCV nl = |

678 |
let (mem_cv, dsk_cv, n1_score, res_cv, off_score) = compDetailedCV nl |

679 |
in mem_cv + dsk_cv + n1_score + res_cv + off_score |

680 | |

681 |
printStats :: NodeList -> String |

682 |
printStats nl = |

683 |
let (mem_cv, dsk_cv, n1_score, res_cv, off_score) = compDetailedCV nl |

684 |
in printf "f_mem=%.8f, r_mem=%.8f, f_dsk=%.8f, n1=%.3f, uf=%.3f" |

685 |
mem_cv res_cv dsk_cv n1_score off_score |

686 | |

687 |
-- Balancing functions |

688 | |

689 |
-- Loading functions |

690 | |

691 |
{- | Convert newline and delimiter-separated text. |

692 | |

693 |
This function converts a text in tabular format as generated by |

694 |
@gnt-instance list@ and @gnt-node list@ to a list of objects using a |

695 |
supplied conversion function. |

696 | |

697 |
-} |

698 |
loadTabular :: (Monad m) => String -> ([String] -> m (String, a)) |

699 |
-> (a -> Int -> a) -> m ([(String, Int)], [(Int, a)]) |

700 |
loadTabular text_data convert_fn set_fn = do |

701 |
let lines_data = lines text_data |

702 |
rows = map (sepSplit '|') lines_data |

703 |
kerows <- mapM convert_fn rows |

704 |
let idxrows = map (\ (idx, (k, v)) -> ((k, idx), (idx, set_fn v idx))) |

705 |
(zip [0..] kerows) |

706 |
return $ unzip idxrows |

707 | |

708 |
-- | For each instance, add its index to its primary and secondary nodes |

709 |
fixNodes :: [(Int, Node.Node)] |

710 |
-> [(Int, Instance.Instance)] |

711 |
-> [(Int, Node.Node)] |

712 |
fixNodes nl il = |

713 |
foldl' (\accu (idx, inst) -> |

714 |
let |

715 |
assocEqual = (\ (i, _) (j, _) -> i == j) |

716 |
pdx = Instance.pnode inst |

717 |
sdx = Instance.snode inst |

718 |
pold = fromJust $ lookup pdx accu |

719 |
sold = fromJust $ lookup sdx accu |

720 |
pnew = Node.setPri pold idx |

721 |
snew = Node.setSec sold idx |

722 |
ac1 = deleteBy assocEqual (pdx, pold) accu |

723 |
ac2 = deleteBy assocEqual (sdx, sold) ac1 |

724 |
ac3 = (pdx, pnew):(sdx, snew):ac2 |

725 |
in ac3) nl il |

726 | |

727 |
-- | Compute the longest common suffix of a NameList list that |

728 |
-- | starts with a dot |

729 |
longestDomain :: NameList -> String |

730 |
longestDomain [] = "" |

731 |
longestDomain ((_,x):xs) = |

732 |
let |

733 |
onlyStrings = snd $ unzip xs |

734 |
in |

735 |
foldr (\ suffix accu -> if all (isSuffixOf suffix) onlyStrings |

736 |
then suffix |

737 |
else accu) |

738 |
"" $ filter (isPrefixOf ".") (tails x) |

739 | |

740 |
-- | Remove tails from the (Int, String) lists |

741 |
stripSuffix :: String -> NameList -> NameList |

742 |
stripSuffix suffix lst = |

743 |
let sflen = length suffix in |

744 |
map (\ (key, name) -> (key, take ((length name) - sflen) name)) lst |

745 | |

746 |
-- | Lookups a node into an assoc list |

747 |
lookupNode :: (Monad m) => String -> String -> [(String, Int)] -> m Int |

748 |
lookupNode node inst ktn = |

749 |
case lookup node ktn of |

750 |
Nothing -> fail $ "Unknown node " ++ node ++ " for instance " ++ inst |

751 |
Just idx -> return idx |

752 | |

753 |
{-| Initializer function that loads the data from a node and list file |

754 |
and massages it into the correct format. -} |

755 |
loadData :: String -- ^ Node data in text format |

756 |
-> String -- ^ Instance data in text format |

757 |
-> Result (Container.Container Node.Node, |

758 |
Container.Container Instance.Instance, |

759 |
String, NameList, NameList) |

760 |
loadData ndata idata = do |

761 |
{- node file: name t_mem n_mem f_mem t_disk f_disk -} |

762 |
(ktn, nl) <- loadTabular ndata |

763 |
(\ (name:tm:nm:fm:td:fd:fo:[]) -> |

764 |
return (name, |

765 |
if any (== "?") [tm,nm,fm,td,fd] || fo == "Y" then |

766 |
Node.create 0 0 0 0 0 True |

767 |
else |

768 |
Node.create (read tm) (read nm) (read fm) |

769 |
(read td) (read fd) False |

770 |
)) |

771 |
Node.setIdx |

772 |
{- instance file: name mem disk status pnode snode -} |

773 |
(kti, il) <- loadTabular idata |

774 |
(\ (name:mem:dsk:status:pnode:snode:[]) -> do |

775 |
pidx <- lookupNode pnode name ktn |

776 |
sidx <- lookupNode snode name ktn |

777 |
let newinst = Instance.create (read mem) (read dsk) |

778 |
status pidx sidx |

779 |
return (name, newinst) |

780 |
) |

781 |
Instance.setIdx |

782 |
let |

783 |
nl2 = fixNodes nl il |

784 |
il3 = Container.fromAssocList il |

785 |
nl3 = Container.fromAssocList |

786 |
(map (\ (k, v) -> (k, Node.buildPeers v il3 (length nl2))) nl2) |

787 |
xtn = swapPairs ktn |

788 |
xti = swapPairs kti |

789 |
common_suffix = longestDomain (xti ++ xtn) |

790 |
stn = stripSuffix common_suffix xtn |

791 |
sti = stripSuffix common_suffix xti |

792 |
return (nl3, il3, common_suffix, stn, sti) |

793 | |

794 |
-- | Compute the amount of memory used by primary instances on a node. |

795 |
nodeImem :: Node.Node -> InstanceList -> Int |

796 |
nodeImem node il = |

797 |
let rfind = flip Container.find $ il |

798 |
in sum . map Instance.mem . |

799 |
map rfind $ Node.plist node |

800 | |

801 |
-- | Compute the amount of disk used by instances on a node (either primary |

802 |
-- or secondary). |

803 |
nodeIdsk :: Node.Node -> InstanceList -> Int |

804 |
nodeIdsk node il = |

805 |
let rfind = flip Container.find $ il |

806 |
in sum . map Instance.dsk . |

807 |
map rfind $ (Node.plist node) ++ (Node.slist node) |

808 | |

809 | |

810 |
-- | Check cluster data for consistency |

811 |
checkData :: NodeList -> InstanceList -> NameList -> NameList |

812 |
-> ([String], NodeList) |

813 |
checkData nl il ktn _ = |

814 |
Container.mapAccum |

815 |
(\ msgs node -> |

816 |
let nname = fromJust $ lookup (Node.idx node) ktn |

817 |
nilst = map (flip Container.find $ il) (Node.plist node) |

818 |
dilst = filter (not . Instance.running) nilst |

819 |
adj_mem = sum . map Instance.mem $ dilst |

820 |
delta_mem = (truncate $ Node.t_mem node) |

821 |
- (Node.n_mem node) |

822 |
- (Node.f_mem node) |

823 |
- (nodeImem node il) |

824 |
+ adj_mem |

825 |
delta_dsk = (truncate $ Node.t_dsk node) |

826 |
- (Node.f_dsk node) |

827 |
- (nodeIdsk node il) |

828 |
newn = Node.setFmem (Node.setXmem node delta_mem) |

829 |
(Node.f_mem node - adj_mem) |

830 |
umsg1 = if delta_mem > 512 || delta_dsk > 1024 |

831 |
then [printf "node %s is missing %d MB ram \ |

832 |
\and %d GB disk" |

833 |
nname delta_mem (delta_dsk `div` 1024)] |

834 |
else [] |

835 |
in (msgs ++ umsg1, newn) |

836 |
) [] nl |