The redundancy level of a group is the number of nodes that can sequentially fail while still keeping it possible to have all instances on the cluster. As per our design, we estimate this level by assuming for an N+1 redundant cluster that the worst next failure is that of the biggest node.
Signed-off-by: Klaus Aehlig <[email protected]> --- Makefile.am | 1 + src/Ganeti/HTools/RedundancyLevel.hs | 76 ++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) create mode 100644 src/Ganeti/HTools/RedundancyLevel.hs diff --git a/Makefile.am b/Makefile.am index b5a353d..f4d8c6d 100644 --- a/Makefile.am +++ b/Makefile.am @@ -953,6 +953,7 @@ HS_LIB_SRCS = \ src/Ganeti/HTools/Program/Hsqueeze.hs \ src/Ganeti/HTools/Program/Hroller.hs \ src/Ganeti/HTools/Program/Main.hs \ + src/Ganeti/HTools/RedundancyLevel.hs \ src/Ganeti/HTools/Repair.hs \ src/Ganeti/HTools/Tags.hs \ src/Ganeti/HTools/Tags/Constants.hs \ diff --git a/src/Ganeti/HTools/RedundancyLevel.hs b/src/Ganeti/HTools/RedundancyLevel.hs new file mode 100644 index 0000000..efd6a26 --- /dev/null +++ b/src/Ganeti/HTools/RedundancyLevel.hs @@ -0,0 +1,76 @@ +{-| Implementation of the computation of the cluster redundancy level + +-} + +{- + +Copyright (C) 2015 Google Inc. +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +1. Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimer. + +2. Redistributions in binary form must reproduce the above copyright +notice, this list of conditions and the following disclaimer in the +documentation and/or other materials provided with the distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR +CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, +EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +-} + +module Ganeti.HTools.RedundancyLevel + ( redundancy + ) where + +import Control.Applicative (liftA2) +import Control.Arrow ((&&&)) +import Data.Function (on) +import qualified Data.IntMap as IntMap +import Data.List (sortBy) + +import Ganeti.BasicTypes (runListHead) +import Ganeti.HTools.AlgorithmParams (AlgorithmOptions) +import Ganeti.HTools.GlobalN1 (redundant) +import qualified Ganeti.HTools.Cluster as Cluster +import qualified Ganeti.HTools.Cluster.Metrics as Metrics +import qualified Ganeti.HTools.Container as Container +import qualified Ganeti.HTools.Instance as Instance +import qualified Ganeti.HTools.Node as Node +import Ganeti.Utils (iterateJust) + +-- | Estimate the level of redundancy of node group given +-- by its nodes and instances. +redundancy :: AlgorithmOptions -> Node.List -> Instance.List -> Int +redundancy _ nl _ | any (liftA2 (&&) Node.offline $ not . null . Node.pList) + $ IntMap.elems nl = -1 +redundancy opts nl il | not $ redundant opts nl il = 0 +redundancy opts nl il = + let sortedNodes = + sortBy (compare `on` ((Node.tMem . snd) &&& fst)) + . filter (not . Node.offline . snd) + $ IntMap.toAscList nl + in case sortedNodes of + [] -> 0 + (bidx, bNode):_ -> + let bNode' = bNode { Node.offline = True } + nl' = Container.add bidx bNode' nl + ini_cv = Metrics.compCV nl' + ini_tbl = Cluster.Table nl' il ini_cv [] + Cluster.Table nl'' il' _ _ = + runListHead ini_tbl id . reverse + $ iterateJust (Cluster.tryBalance opts) ini_tbl + in 1 + redundancy opts nl'' il' -- 2.6.0.rc2.230.g3dd15c0
