{-| Module describing an instance. The instance data type holds very few fields, the algorithm intelligence is in the "Node" and "Cluster" modules. -} {- Copyright (C) 2009, 2010, 2011 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.Instance ( Instance(..) , AssocList , List , create , setIdx , setName , setAlias , setPri , setSec , setBoth , setMovable , specOf , shrinkByType , runningStates , localStorageTemplates , hasSecondary , requiredNodes , allNodes , usesLocalStorage ) where import qualified Ganeti.HTools.Types as T import qualified Ganeti.HTools.Container as Container import qualified Ganeti.Constants as C -- * Type declarations -- | The instance type. data Instance = Instance { name :: String -- ^ The instance name , alias :: String -- ^ The shortened name , mem :: Int -- ^ Memory of the instance , dsk :: Int -- ^ Disk size of instance , vcpus :: Int -- ^ Number of VCPUs , running :: Bool -- ^ Is the instance running? , runSt :: String -- ^ Original (text) run status , pNode :: T.Ndx -- ^ Original primary node , sNode :: T.Ndx -- ^ Original secondary node , idx :: T.Idx -- ^ Internal index , util :: T.DynUtil -- ^ Dynamic resource usage , movable :: Bool -- ^ Can and should the instance be moved? , autoBalance :: Bool -- ^ Is the instance auto-balanced? , tags :: [String] -- ^ List of instance tags , diskTemplate :: T.DiskTemplate -- ^ The disk template of the instance } deriving (Show, Read) instance T.Element Instance where nameOf = name idxOf = idx setAlias = setAlias setIdx = setIdx allNames n = [name n, alias n] -- | Constant holding the running instance states. runningStates :: [String] runningStates = [C.inststRunning, C.inststErrorup] -- | Constant holding the local storage templates. -- -- /Note:/ Currently Ganeti only exports node total/free disk space -- for LVM-based storage; file-based storage is ignored in this model, -- so even though file-based storage uses in reality disk space on the -- node, in our model it won't affect it and we can't compute whether -- there is enough disk space for a file-based instance. Therefore we -- will treat this template as \'foreign\' storage. localStorageTemplates :: [T.DiskTemplate] localStorageTemplates = [ T.DTDrbd8, T.DTPlain ] -- | Constant holding the movable disk templates. -- -- This only determines the initial 'movable' state of the -- instance. Further the movable state can be restricted more due to -- user choices, etc. movableDiskTemplates :: [T.DiskTemplate] movableDiskTemplates = [ T.DTDrbd8, T.DTBlock, T.DTSharedFile ] -- | A simple name for the int, instance association list. type AssocList = [(T.Idx, Instance)] -- | A simple name for an instance map. type List = Container.Container Instance -- * Initialization -- | Create an instance. -- -- Some parameters are not initialized by function, and must be set -- later (via 'setIdx' for example). create :: String -> Int -> Int -> Int -> String -> [String] -> Bool -> T.Ndx -> T.Ndx -> T.DiskTemplate -> Instance create name_init mem_init dsk_init vcpus_init run_init tags_init auto_balance_init pn sn dt = Instance { name = name_init , alias = name_init , mem = mem_init , dsk = dsk_init , vcpus = vcpus_init , running = run_init `elem` runningStates , runSt = run_init , pNode = pn , sNode = sn , idx = -1 , util = T.baseUtil , tags = tags_init , movable = supportsMoves dt , autoBalance = auto_balance_init , diskTemplate = dt } -- | Changes the index. -- -- This is used only during the building of the data structures. setIdx :: Instance -- ^ The original instance -> T.Idx -- ^ New index -> Instance -- ^ The modified instance setIdx t i = t { idx = i } -- | Changes the name. -- -- This is used only during the building of the data structures. setName :: Instance -- ^ The original instance -> String -- ^ New name -> Instance -- ^ The modified instance setName t s = t { name = s, alias = s } -- | Changes the alias. -- -- This is used only during the building of the data structures. setAlias :: Instance -- ^ The original instance -> String -- ^ New alias -> Instance -- ^ The modified instance setAlias t s = t { alias = s } -- * Update functions -- | Changes the primary node of the instance. setPri :: Instance -- ^ the original instance -> T.Ndx -- ^ the new primary node -> Instance -- ^ the modified instance setPri t p = t { pNode = p } -- | Changes the secondary node of the instance. setSec :: Instance -- ^ the original instance -> T.Ndx -- ^ the new secondary node -> Instance -- ^ the modified instance setSec t s = t { sNode = s } -- | Changes both nodes of the instance. setBoth :: Instance -- ^ the original instance -> T.Ndx -- ^ new primary node index -> T.Ndx -- ^ new secondary node index -> Instance -- ^ the modified instance setBoth t p s = t { pNode = p, sNode = s } -- | Sets the movable flag on an instance. setMovable :: Instance -- ^ The original instance -> Bool -- ^ New movable flag -> Instance -- ^ The modified instance setMovable t m = t { movable = m } -- | Try to shrink the instance based on the reason why we can't -- allocate it. shrinkByType :: Instance -> T.FailMode -> T.Result Instance shrinkByType inst T.FailMem = let v = mem inst - T.unitMem in if v < T.unitMem then T.Bad "out of memory" else T.Ok inst { mem = v } shrinkByType inst T.FailDisk = let v = dsk inst - T.unitDsk in if v < T.unitDsk then T.Bad "out of disk" else T.Ok inst { dsk = v } shrinkByType inst T.FailCPU = let v = vcpus inst - T.unitCpu in if v < T.unitCpu then T.Bad "out of vcpus" else T.Ok inst { vcpus = v } shrinkByType _ f = T.Bad $ "Unhandled failure mode " ++ show f -- | Return the spec of an instance. specOf :: Instance -> T.RSpec specOf Instance { mem = m, dsk = d, vcpus = c } = T.RSpec { T.rspecCpu = c, T.rspecMem = m, T.rspecDsk = d } -- | Checks whether the instance uses a secondary node. -- -- /Note:/ This should be reconciled with @'sNode' == -- 'Node.noSecondary'@. hasSecondary :: Instance -> Bool hasSecondary = (== T.DTDrbd8) . diskTemplate -- | Computed the number of nodes for a given disk template. requiredNodes :: T.DiskTemplate -> Int requiredNodes T.DTDrbd8 = 2 requiredNodes _ = 1 -- | Computes all nodes of an instance. allNodes :: Instance -> [T.Ndx] allNodes inst = case diskTemplate inst of T.DTDrbd8 -> [pNode inst, sNode inst] _ -> [pNode inst] -- | Checks whether a given disk template uses local storage. usesLocalStorage :: Instance -> Bool usesLocalStorage = (`elem` localStorageTemplates) . diskTemplate -- | Checks whether a given disk template supported moves. supportsMoves :: T.DiskTemplate -> Bool supportsMoves = (`elem` movableDiskTemplates)