root / htools / Ganeti / HTools / IAlloc.hs @ 135f64a3
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{-| Implementation of the iallocator interface. |
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-} |
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{- |
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Copyright (C) 2009, 2010, 2011 Google Inc. |
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|
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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02110-1301, USA. |
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-} |
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module Ganeti.HTools.IAlloc |
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( readRequest |
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, runIAllocator |
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, processRelocate |
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) where |
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|
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import Data.Either () |
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import Data.Maybe (fromMaybe, isJust) |
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import Data.List |
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import Control.Monad |
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import Text.JSON (JSObject, JSValue(JSArray), |
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makeObj, encodeStrict, decodeStrict, fromJSObject, showJSON) |
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import System.Exit |
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import System.IO |
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|
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import qualified Ganeti.HTools.Cluster as Cluster |
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import qualified Ganeti.HTools.Container as Container |
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import qualified Ganeti.HTools.Group as Group |
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import qualified Ganeti.HTools.Node as Node |
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import qualified Ganeti.HTools.Instance as Instance |
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import qualified Ganeti.Constants as C |
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import Ganeti.HTools.CLI |
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import Ganeti.HTools.Loader |
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import Ganeti.HTools.ExtLoader (loadExternalData) |
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import Ganeti.HTools.JSON |
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import Ganeti.HTools.Types |
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{-# ANN module "HLint: ignore Eta reduce" #-} |
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|
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-- | Type alias for the result of an IAllocator call. |
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type IAllocResult = (String, JSValue, Node.List, Instance.List) |
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|
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-- | Parse the basic specifications of an instance. |
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-- |
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-- Instances in the cluster instance list and the instance in an |
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-- 'Allocate' request share some common properties, which are read by |
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-- this function. |
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parseBaseInstance :: String |
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-> JSRecord |
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-> Result (String, Instance.Instance) |
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parseBaseInstance n a = do |
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let extract x = tryFromObj ("invalid data for instance '" ++ n ++ "'") a x |
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disk <- extract "disk_space_total" |
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mem <- extract "memory" |
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vcpus <- extract "vcpus" |
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tags <- extract "tags" |
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dt <- extract "disk_template" |
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return (n, Instance.create n mem disk vcpus Running tags True 0 0 dt) |
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|
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-- | Parses an instance as found in the cluster instance list. |
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parseInstance :: NameAssoc -- ^ The node name-to-index association list |
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-> String -- ^ The name of the instance |
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-> JSRecord -- ^ The JSON object |
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-> Result (String, Instance.Instance) |
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parseInstance ktn n a = do |
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base <- parseBaseInstance n a |
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nodes <- fromObj a "nodes" |
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pnode <- if null nodes |
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then Bad $ "empty node list for instance " ++ n |
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else readEitherString $ head nodes |
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pidx <- lookupNode ktn n pnode |
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let snodes = tail nodes |
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sidx <- if null snodes |
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then return Node.noSecondary |
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else readEitherString (head snodes) >>= lookupNode ktn n |
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return (n, Instance.setBoth (snd base) pidx sidx) |
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|
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-- | Parses a node as found in the cluster node list. |
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parseNode :: NameAssoc -- ^ The group association |
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-> String -- ^ The node's name |
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-> JSRecord -- ^ The JSON object |
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-> Result (String, Node.Node) |
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parseNode ktg n a = do |
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let desc = "invalid data for node '" ++ n ++ "'" |
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extract x = tryFromObj desc a x |
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offline <- extract "offline" |
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drained <- extract "drained" |
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guuid <- extract "group" |
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vm_capable <- annotateResult desc $ maybeFromObj a "vm_capable" |
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let vm_capable' = fromMaybe True vm_capable |
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gidx <- lookupGroup ktg n guuid |
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node <- if offline || drained || not vm_capable' |
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then return $ Node.create n 0 0 0 0 0 0 True gidx |
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else do |
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mtotal <- extract "total_memory" |
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mnode <- extract "reserved_memory" |
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mfree <- extract "free_memory" |
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dtotal <- extract "total_disk" |
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dfree <- extract "free_disk" |
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ctotal <- extract "total_cpus" |
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return $ Node.create n mtotal mnode mfree |
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dtotal dfree ctotal False gidx |
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return (n, node) |
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|
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-- | Parses a group as found in the cluster group list. |
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parseGroup :: String -- ^ The group UUID |
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-> JSRecord -- ^ The JSON object |
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-> Result (String, Group.Group) |
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parseGroup u a = do |
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let extract x = tryFromObj ("invalid data for group '" ++ u ++ "'") a x |
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name <- extract "name" |
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apol <- extract "alloc_policy" |
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return (u, Group.create name u apol) |
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|
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-- | Top-level parser. |
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-- |
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-- The result is a tuple of eventual warning messages and the parsed |
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-- request; if parsing the input data fails, we'll return a 'Bad' |
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-- value. |
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parseData :: String -- ^ The JSON message as received from Ganeti |
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-> Result ([String], Request) -- ^ Result tuple |
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parseData body = do |
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decoded <- fromJResult "Parsing input IAllocator message" (decodeStrict body) |
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let obj = fromJSObject decoded |
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extrObj x = tryFromObj "invalid iallocator message" obj x |
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-- request parser |
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request <- liftM fromJSObject (extrObj "request") |
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let extrReq x = tryFromObj "invalid request dict" request x |
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-- existing group parsing |
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glist <- liftM fromJSObject (extrObj "nodegroups") |
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gobj <- mapM (\(x, y) -> asJSObject y >>= parseGroup x . fromJSObject) glist |
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let (ktg, gl) = assignIndices gobj |
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-- existing node parsing |
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nlist <- liftM fromJSObject (extrObj "nodes") |
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nobj <- mapM (\(x,y) -> |
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asJSObject y >>= parseNode ktg x . fromJSObject) nlist |
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let (ktn, nl) = assignIndices nobj |
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-- existing instance parsing |
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ilist <- extrObj "instances" |
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let idata = fromJSObject ilist |
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iobj <- mapM (\(x,y) -> |
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asJSObject y >>= parseInstance ktn x . fromJSObject) idata |
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let (kti, il) = assignIndices iobj |
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-- cluster tags |
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ctags <- extrObj "cluster_tags" |
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cdata1 <- mergeData [] [] [] [] (ClusterData gl nl il ctags defIPolicy) |
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let (msgs, fix_nl) = checkData (cdNodes cdata1) (cdInstances cdata1) |
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cdata = cdata1 { cdNodes = fix_nl } |
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map_n = cdNodes cdata |
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map_i = cdInstances cdata |
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map_g = cdGroups cdata |
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optype <- extrReq "type" |
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rqtype <- |
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case () of |
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_ | optype == C.iallocatorModeAlloc -> |
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do |
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rname <- extrReq "name" |
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req_nodes <- extrReq "required_nodes" |
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inew <- parseBaseInstance rname request |
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let io = snd inew |
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return $ Allocate io req_nodes |
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| optype == C.iallocatorModeReloc -> |
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do |
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rname <- extrReq "name" |
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ridx <- lookupInstance kti rname |
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req_nodes <- extrReq "required_nodes" |
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ex_nodes <- extrReq "relocate_from" |
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ex_idex <- mapM (Container.findByName map_n) ex_nodes |
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return $ Relocate ridx req_nodes (map Node.idx ex_idex) |
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| optype == C.iallocatorModeChgGroup -> |
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do |
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rl_names <- extrReq "instances" |
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rl_insts <- mapM (liftM Instance.idx . |
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Container.findByName map_i) rl_names |
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gr_uuids <- extrReq "target_groups" |
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gr_idxes <- mapM (liftM Group.idx . |
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Container.findByName map_g) gr_uuids |
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return $ ChangeGroup rl_insts gr_idxes |
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| optype == C.iallocatorModeNodeEvac -> |
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do |
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rl_names <- extrReq "instances" |
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rl_insts <- mapM (Container.findByName map_i) rl_names |
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let rl_idx = map Instance.idx rl_insts |
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rl_mode <- extrReq "evac_mode" |
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return $ NodeEvacuate rl_idx rl_mode |
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| otherwise -> fail ("Invalid request type '" ++ optype ++ "'") |
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return (msgs, Request rqtype cdata) |
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-- | Formats the result into a valid IAllocator response message. |
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formatResponse :: Bool -- ^ Whether the request was successful |
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-> String -- ^ Information text |
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-> JSValue -- ^ The JSON encoded result |
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-> String -- ^ The full JSON-formatted message |
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formatResponse success info result = |
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let e_success = ("success", showJSON success) |
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e_info = ("info", showJSON info) |
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e_result = ("result", result) |
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in encodeStrict $ makeObj [e_success, e_info, e_result] |
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-- | Flatten the log of a solution into a string. |
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describeSolution :: Cluster.AllocSolution -> String |
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describeSolution = intercalate ", " . Cluster.asLog |
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-- | Convert allocation/relocation results into the result format. |
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formatAllocate :: Instance.List -> Cluster.AllocSolution -> Result IAllocResult |
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formatAllocate il as = do |
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let info = describeSolution as |
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case Cluster.asSolution as of |
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Nothing -> fail info |
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Just (nl, inst, nodes, _) -> |
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do |
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let il' = Container.add (Instance.idx inst) inst il |
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return (info, showJSON $ map Node.name nodes, nl, il') |
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|
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-- | Convert a node-evacuation/change group result. |
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formatNodeEvac :: Group.List |
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-> Node.List |
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-> Instance.List |
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-> (Node.List, Instance.List, Cluster.EvacSolution) |
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-> Result IAllocResult |
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formatNodeEvac gl nl il (fin_nl, fin_il, es) = |
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let iname = Instance.name . flip Container.find il |
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nname = Node.name . flip Container.find nl |
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gname = Group.name . flip Container.find gl |
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fes = map (\(idx, msg) -> (iname idx, msg)) $ Cluster.esFailed es |
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mes = map (\(idx, gdx, ndxs) -> (iname idx, gname gdx, map nname ndxs)) |
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$ Cluster.esMoved es |
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failed = length fes |
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moved = length mes |
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info = show failed ++ " instances failed to move and " ++ show moved ++ |
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" were moved successfully" |
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in Ok (info, showJSON (mes, fes, Cluster.esOpCodes es), fin_nl, fin_il) |
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-- | Runs relocate for a single instance. |
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-- |
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-- This is wrapper over the 'Cluster.tryNodeEvac' function that is run |
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-- with a single instance (ours), and further it checks that the |
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-- result it got (in the nodes field) is actually consistent, as |
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-- tryNodeEvac is designed to output primarily an opcode list, not a |
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-- node list. |
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processRelocate :: Group.List -- ^ The group list |
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-> Node.List -- ^ The node list |
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-> Instance.List -- ^ The instance list |
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-> Idx -- ^ The index of the instance to move |
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-> Int -- ^ The number of nodes required |
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-> [Ndx] -- ^ Nodes which should not be used |
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-> Result (Node.List, Instance.List, [Ndx]) -- ^ Solution list |
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processRelocate gl nl il idx 1 exndx = do |
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let orig = Container.find idx il |
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sorig = Instance.sNode orig |
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when (exndx /= [sorig]) $ |
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-- FIXME: we can't use the excluded nodes here; the logic is |
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-- already _but only partially_ implemented in tryNodeEvac... |
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fail $ "Unsupported request: excluded nodes not equal to\ |
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\ instance's secondary node (" ++ show sorig ++ " versus " ++ |
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show exndx ++ ")" |
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(nl', il', esol) <- Cluster.tryNodeEvac gl nl il ChangeSecondary [idx] |
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nodes <- case lookup idx (Cluster.esFailed esol) of |
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Just msg -> fail msg |
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Nothing -> |
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case lookup idx (map (\(a, _, b) -> (a, b)) |
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(Cluster.esMoved esol)) of |
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Nothing -> |
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fail "Internal error: lost instance idx during move" |
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Just n -> return n |
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let inst = Container.find idx il' |
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pnode = Instance.pNode inst |
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snode = Instance.sNode inst |
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when (snode == sorig) $ |
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fail "Internal error: instance didn't change secondary node?!" |
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when (snode == pnode) $ |
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fail "Internal error: selected primary as new secondary?!" |
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nodes' <- if nodes == [pnode, snode] |
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then return [snode] -- only the new secondary is needed |
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else fail $ "Internal error: inconsistent node list (" ++ |
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show nodes ++ ") versus instance nodes (" ++ show pnode ++ |
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"," ++ show snode ++ ")" |
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return (nl', il', nodes') |
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processRelocate _ _ _ _ reqn _ = |
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fail $ "Exchange " ++ show reqn ++ " nodes mode is not implemented" |
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formatRelocate :: (Node.List, Instance.List, [Ndx]) |
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-> Result IAllocResult |
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formatRelocate (nl, il, ndxs) = |
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let nodes = map (`Container.find` nl) ndxs |
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names = map Node.name nodes |
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in Ok ("success", showJSON names, nl, il) |
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-- | Process a request and return new node lists. |
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processRequest :: Request -> Result IAllocResult |
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processRequest request = |
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let Request rqtype (ClusterData gl nl il _ _) = request |
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in case rqtype of |
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Allocate xi reqn -> |
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Cluster.tryMGAlloc gl nl il xi reqn >>= formatAllocate il |
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Relocate idx reqn exnodes -> |
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processRelocate gl nl il idx reqn exnodes >>= formatRelocate |
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ChangeGroup gdxs idxs -> |
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Cluster.tryChangeGroup gl nl il idxs gdxs >>= |
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formatNodeEvac gl nl il |
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NodeEvacuate xi mode -> |
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Cluster.tryNodeEvac gl nl il mode xi >>= |
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formatNodeEvac gl nl il |
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-- | Reads the request from the data file(s). |
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readRequest :: Options -> [String] -> IO Request |
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readRequest opts args = do |
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when (null args) $ do |
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hPutStrLn stderr "Error: this program needs an input file." |
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exitWith $ ExitFailure 1 |
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input_data <- readFile (head args) |
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r1 <- case parseData input_data of |
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Bad err -> do |
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hPutStrLn stderr $ "Error: " ++ err |
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exitWith $ ExitFailure 1 |
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Ok (fix_msgs, rq) -> maybeShowWarnings fix_msgs >> return rq |
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if isJust (optDataFile opts) || (not . null . optNodeSim) opts |
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then do |
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cdata <- loadExternalData opts |
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let Request rqt _ = r1 |
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return $ Request rqt cdata |
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else return r1 |
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|
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-- | Main iallocator pipeline. |
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runIAllocator :: Request -> (Maybe (Node.List, Instance.List), String) |
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runIAllocator request = |
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let (ok, info, result, cdata) = |
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case processRequest request of |
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Ok (msg, r, nl, il) -> (True, "Request successful: " ++ msg, r, |
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Just (nl, il)) |
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Bad msg -> (False, "Request failed: " ++ msg, JSArray [], Nothing) |
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rstring = formatResponse ok info result |
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in (cdata, rstring) |