Synnefo » snf-ganeti

{-| Module describing a node.

    All updates are functional (copy-based) and return a new node with

    updated value.

-}

module Ganeti.HTools.Node

    ( Node(failN1, name, idx, t_mem, n_mem, f_mem, r_mem, t_dsk, f_dsk,

           p_mem, p_dsk, p_rem,

           plist, slist, offline)

    , List

    -- * Constructor

    , create

    -- ** Finalization after data loading

    , buildPeers

    , setIdx

    , setName

    , setOffline

    , setXmem

    , setFmem

    , setPri

    , setSec

    -- * Instance (re)location

    , removePri

    , removeSec

    , addPri

    , addSec

    -- * Formatting

    , list

    -- * Misc stuff

    , AssocList

    , noSecondary

    ) where

import Data.List

import Text.Printf (printf)

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Instance as Instance

import qualified Ganeti.HTools.PeerMap as PeerMap

import qualified Ganeti.HTools.Types as T

-- * Type declarations

-- | The node type.

data Node = Node { name  :: String -- ^ The node name

                 , t_mem :: Double -- ^ Total memory (MiB)

                 , n_mem :: Int    -- ^ Node memory (MiB)

                 , f_mem :: Int    -- ^ Free memory (MiB)

                 , x_mem :: Int    -- ^ Unaccounted memory (MiB)

                 , t_dsk :: Double -- ^ Total disk space (MiB)

                 , f_dsk :: Int    -- ^ Free disk space (MiB)

                 , plist :: [T.Idx]-- ^ List of primary instance indices

                 , slist :: [T.Idx]-- ^ List of secondary instance indices

                 , idx :: T.Ndx    -- ^ Internal index for book-keeping

                 , peers :: PeerMap.PeerMap -- ^ Pnode to instance mapping

                 , failN1:: Bool   -- ^ Whether the node has failed n1

                 , r_mem :: Int    -- ^ Maximum memory needed for

                                   -- failover by primaries of this node

                 , p_mem :: Double -- ^ Percent of free memory

                 , p_dsk :: Double -- ^ Percent of free disk

                 , p_rem :: Double -- ^ Percent of reserved memory

                 , offline :: Bool -- ^ Whether the node should not be used

                                   -- for allocations and skipped from

                                   -- score computations

  } deriving (Show)

instance T.Element Node where

    nameOf = name

    idxOf = idx

    setName = setName

    setIdx = setIdx

-- | A simple name for the int, node association list.

type AssocList = [(T.Ndx, Node)]

-- | A simple name for a node map.

type List = Container.Container Node

-- | Constant node index for a non-moveable instance.

noSecondary :: T.Ndx

noSecondary = -1

-- * Initialization functions

-- | Create a new node.

--

-- The index and the peers maps are empty, and will be need to be

-- update later via the 'setIdx' and 'buildPeers' functions.

create :: String -> Double -> Int -> Int -> Double -> Int -> Bool -> Node

create name_init mem_t_init mem_n_init mem_f_init

       dsk_t_init dsk_f_init offline_init =

    Node

    {

      name  = name_init,

      t_mem = mem_t_init,

      n_mem = mem_n_init,

      f_mem = mem_f_init,

      t_dsk = dsk_t_init,

      f_dsk = dsk_f_init,

      plist = [],

      slist = [],

      failN1 = True,

      idx = -1,

      peers = PeerMap.empty,

      r_mem = 0,

      p_mem = (fromIntegral mem_f_init) / mem_t_init,

      p_dsk = (fromIntegral dsk_f_init) / dsk_t_init,

      p_rem = 0,

      offline = offline_init,

      x_mem = 0

    }

-- | Changes the index.

--

-- This is used only during the building of the data structures.

setIdx :: Node -> T.Ndx -> Node

setIdx t i = t {idx = i}

-- | Changes the name.

--

-- This is used only during the building of the data structures.

setName :: Node -> String -> Node

setName t s = t {name = s}

-- | Sets the offline attribute.

setOffline :: Node -> Bool -> Node

setOffline t val = t { offline = val }

-- | Sets the unnaccounted memory.

setXmem :: Node -> Int -> Node

setXmem t val = t { x_mem = val }

-- | Computes the maximum reserved memory for peers from a peer map.

computeMaxRes :: PeerMap.PeerMap -> PeerMap.Elem

computeMaxRes new_peers = PeerMap.maxElem new_peers

-- | Builds the peer map for a given node.

buildPeers :: Node -> Instance.List -> Node

buildPeers t il =

    let mdata = map

                (\i_idx -> let inst = Container.find i_idx il

                           in (Instance.pnode inst, Instance.mem inst))

                (slist t)

        pmap = PeerMap.accumArray (+) mdata

        new_rmem = computeMaxRes pmap

        new_failN1 = computeFailN1 new_rmem (f_mem t) (f_dsk t)

        new_prem = (fromIntegral new_rmem) / (t_mem t)

    in t {peers=pmap, failN1 = new_failN1, r_mem = new_rmem, p_rem = new_prem}

-- | Assigns an instance to a node as primary without other updates.

setPri :: Node -> T.Idx -> Node

setPri t idx = t { plist = idx:(plist t) }

-- | Assigns an instance to a node as secondary without other updates.

setSec :: Node -> T.Idx -> Node

setSec t idx = t { slist = idx:(slist t) }

-- * Update functions

-- | Sets the free memory.

setFmem :: Node -> Int -> Node

setFmem t new_mem =

    let new_n1 = computeFailN1 (r_mem t) new_mem (f_dsk t)

        new_mp = (fromIntegral new_mem) / (t_mem t)

    in

      t { f_mem = new_mem, failN1 = new_n1, p_mem = new_mp }

-- | Given the rmem, free memory and disk, computes the failn1 status.

computeFailN1 :: Int -> Int -> Int -> Bool

computeFailN1 new_rmem new_mem new_dsk =

    new_mem <= new_rmem || new_dsk <= 0

-- | Given the new free memory and disk, fail if any of them is below zero.

failHealth :: Int -> Int -> Bool

failHealth new_mem new_dsk = new_mem <= 0 || new_dsk <= 0

-- | Removes a primary instance.

removePri :: Node -> Instance.Instance -> Node

removePri t inst =

    let iname = Instance.idx inst

        new_plist = delete iname (plist t)

        new_mem = f_mem t + Instance.mem inst

        new_dsk = f_dsk t + Instance.dsk inst

        new_mp = (fromIntegral new_mem) / (t_mem t)

        new_dp = (fromIntegral new_dsk) / (t_dsk t)

        new_failn1 = computeFailN1 (r_mem t) new_mem new_dsk

    in t {plist = new_plist, f_mem = new_mem, f_dsk = new_dsk,

          failN1 = new_failn1, p_mem = new_mp, p_dsk = new_dp}

-- | Removes a secondary instance.

removeSec :: Node -> Instance.Instance -> Node

removeSec t inst =

    let iname = Instance.idx inst

        pnode = Instance.pnode inst

        new_slist = delete iname (slist t)

        new_dsk = f_dsk t + Instance.dsk inst

        old_peers = peers t

        old_peem = PeerMap.find pnode old_peers

        new_peem =  old_peem - (Instance.mem inst)

        new_peers = PeerMap.add pnode new_peem old_peers

        old_rmem = r_mem t

        new_rmem = if old_peem < old_rmem then

                       old_rmem

                   else

                       computeMaxRes new_peers

        new_prem = (fromIntegral new_rmem) / (t_mem t)

        new_failn1 = computeFailN1 new_rmem (f_mem t) new_dsk

        new_dp = (fromIntegral new_dsk) / (t_dsk t)

    in t {slist = new_slist, f_dsk = new_dsk, peers = new_peers,

          failN1 = new_failn1, r_mem = new_rmem, p_dsk = new_dp,

          p_rem = new_prem}

-- | Adds a primary instance.

addPri :: Node -> Instance.Instance -> Maybe Node

addPri t inst =

    let iname = Instance.idx inst

        new_mem = f_mem t - Instance.mem inst

        new_dsk = f_dsk t - Instance.dsk inst

        new_failn1 = computeFailN1 (r_mem t) new_mem new_dsk in

      if (failHealth new_mem new_dsk) || (new_failn1 && not (failN1 t)) then

        Nothing

      else

        let new_plist = iname:(plist t)

            new_mp = (fromIntegral new_mem) / (t_mem t)

            new_dp = (fromIntegral new_dsk) / (t_dsk t)

        in

        Just t {plist = new_plist, f_mem = new_mem, f_dsk = new_dsk,

                failN1 = new_failn1, p_mem = new_mp, p_dsk = new_dp}

-- | Adds a secondary instance.

addSec :: Node -> Instance.Instance -> T.Ndx -> Maybe Node

addSec t inst pdx =

    let iname = Instance.idx inst

        old_peers = peers t

        old_mem = f_mem t

        new_dsk = f_dsk t - Instance.dsk inst

        new_peem = PeerMap.find pdx old_peers + Instance.mem inst

        new_peers = PeerMap.add pdx new_peem old_peers

        new_rmem = max (r_mem t) new_peem

        new_prem = (fromIntegral new_rmem) / (t_mem t)

        new_failn1 = computeFailN1 new_rmem old_mem new_dsk in

    if (failHealth old_mem new_dsk) || (new_failn1 && not (failN1 t)) then

        Nothing

    else

        let new_slist = iname:(slist t)

            new_dp = (fromIntegral new_dsk) / (t_dsk t)

        in

        Just t {slist = new_slist, f_dsk = new_dsk,

                peers = new_peers, failN1 = new_failn1,

                r_mem = new_rmem, p_dsk = new_dp,

                p_rem = new_prem}

-- * Display functions

-- | String converter for the node list functionality.

list :: Int -> Node -> String

list mname t =

    let pl = plist t

        sl = slist t

        mp = p_mem t

        dp = p_dsk t

        off = offline t

        fn = failN1 t

        tmem = t_mem t

        nmem = n_mem t

        xmem = x_mem t

        fmem = f_mem t

        imem = (truncate tmem) - nmem - xmem - fmem

    in

      printf " %c %-*s %5.0f %5d %5d %5d %5d %5d %5.0f %5d %3d %3d %.5f %.5f"

                 (if off then '-' else if fn then '*' else ' ')

                 mname (name t) tmem nmem imem xmem fmem (r_mem t)

                 ((t_dsk t) / 1024) ((f_dsk t) `div` 1024)

                 (length pl) (length sl)

                 mp dp