Synnefo » snf-ganeti

{-| Solver for N+1 cluster errors

-}

module Main (main) where

import Data.List

import Data.Function

import Data.Maybe (isJust, fromJust, fromMaybe)

import Monad

import System

import System.IO

import System.Console.GetOpt

import qualified System

import Text.Printf (printf)

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Cluster as Cluster

import qualified Ganeti.HTools.Node as Node

import qualified Ganeti.HTools.CLI as CLI

import Ganeti.HTools.Rapi

import Ganeti.HTools.Utils

-- | Command line options structure.

data Options = Options

    { optShowNodes :: Bool           -- ^ Whether to show node status

    , optShowCmds  :: Maybe FilePath -- ^ Whether to show the command list

    , optOneline   :: Bool           -- ^ Switch output to a single line

    , optNodef     :: FilePath       -- ^ Path to the nodes file

    , optNodeSet   :: Bool           -- ^ The nodes have been set by options

    , optInstf     :: FilePath       -- ^ Path to the instances file

    , optInstSet   :: Bool           -- ^ The insts have been set by options

    , optMaxLength :: Int            -- ^ Stop after this many steps

    , optMaster    :: String         -- ^ Collect data from RAPI

    , optVerbose   :: Int            -- ^ Verbosity level

    , optOffline   :: [String]       -- ^ Names of offline nodes

    , optMinScore  :: Cluster.Score  -- ^ The minimum score we aim for

    , optShowVer   :: Bool           -- ^ Just show the program version

    , optShowHelp  :: Bool           -- ^ Just show the help

    } deriving Show

-- | Default values for the command line options.

defaultOptions :: Options

defaultOptions  = Options

 { optShowNodes = False

 , optShowCmds  = Nothing

 , optOneline   = False

 , optNodef     = "nodes"

 , optNodeSet   = False

 , optInstf     = "instances"

 , optInstSet   = False

 , optMaxLength = -1

 , optMaster    = ""

 , optVerbose   = 0

 , optOffline   = []

 , optMinScore  = 1e-9

 , optShowVer   = False

 , optShowHelp  = False

 }

-- | Options list and functions

options :: [OptDescr (Options -> Options)]

options =

    [ Option ['p']     ["print-nodes"]

      (NoArg (\ opts -> opts { optShowNodes = True }))

      "print the final node list"

    , Option ['C']     ["print-commands"]

      (OptArg ((\ f opts -> opts { optShowCmds = Just f }) . fromMaybe "-")

                  "FILE")

      "print the ganeti command list for reaching the solution,\

      \if an argument is passed then write the commands to a file named\

      \ as such"

    , Option ['o']     ["oneline"]

      (NoArg (\ opts -> opts { optOneline = True }))

      "print the ganeti command list for reaching the solution"

    , Option ['n']     ["nodes"]

      (ReqArg (\ f opts -> opts { optNodef = f, optNodeSet = True }) "FILE")

      "the node list FILE"

    , Option ['i']     ["instances"]

      (ReqArg (\ f opts -> opts { optInstf =  f, optInstSet = True }) "FILE")

      "the instance list FILE"

    , Option ['m']     ["master"]

      (ReqArg (\ m opts -> opts { optMaster = m }) "ADDRESS")

      "collect data via RAPI at the given ADDRESS"

    , Option ['l']     ["max-length"]

      (ReqArg (\ i opts -> opts { optMaxLength =  (read i)::Int }) "N")

      "cap the solution at this many moves (useful for very unbalanced \

      \clusters)"

    , Option ['v']     ["verbose"]

      (NoArg (\ opts -> opts { optVerbose = (optVerbose opts) + 1 }))

      "increase the verbosity level"

    , Option ['O']     ["offline"]

      (ReqArg (\ n opts -> opts { optOffline = n:optOffline opts }) "NODE")

      " set node as offline"

    , Option ['e']     ["min-score"]

      (ReqArg (\ e opts -> opts { optMinScore = read e }) "EPSILON")

      " mininum score to aim for"

    , Option ['V']     ["version"]

      (NoArg (\ opts -> opts { optShowVer = True}))

      "show the version of the program"

    , Option ['h']     ["help"]

      (NoArg (\ opts -> opts { optShowHelp = True}))

      "show help"

    ]

{- | Start computing the solution at the given depth and recurse until

we find a valid solution or we exceed the maximum depth.

-}

iterateDepth :: Cluster.Table    -- ^ The starting table

             -> Int              -- ^ Remaining length

             -> Cluster.NameList -- ^ Node idx to name list

             -> Cluster.NameList -- ^ Inst idx to name list

             -> Int              -- ^ Max node name len

             -> Int              -- ^ Max instance name len

             -> [[String]]       -- ^ Current command list

             -> Bool             -- ^ Wheter to be silent

             -> Cluster.Score    -- ^ Score at which to stop

             -> IO (Cluster.Table, [[String]]) -- ^ The resulting table and

                                               -- commands

iterateDepth ini_tbl max_rounds ktn kti nmlen imlen

             cmd_strs oneline min_score =

    let Cluster.Table ini_nl ini_il ini_cv ini_plc = ini_tbl

        all_inst = Container.elems ini_il

        node_idx = map Node.idx . filter (not . Node.offline) $

                   Container.elems ini_nl

        fin_tbl = Cluster.checkMove node_idx ini_tbl all_inst

        (Cluster.Table _ _ fin_cv fin_plc) = fin_tbl

        ini_plc_len = length ini_plc

        fin_plc_len = length fin_plc

        allowed_next = (max_rounds < 0 || length fin_plc < max_rounds)

    in

      do

        let

            (sol_line, cmds) = Cluster.printSolutionLine ini_il ktn kti

                               nmlen imlen (head fin_plc) fin_plc_len

            upd_cmd_strs = cmds:cmd_strs

        unless (oneline || fin_plc_len == ini_plc_len) $ do

          putStrLn sol_line

          hFlush stdout

        (if fin_cv < ini_cv then -- this round made success, try deeper

             if allowed_next && fin_cv > min_score

             then iterateDepth fin_tbl max_rounds ktn kti

                  nmlen imlen upd_cmd_strs oneline min_score

             -- don't go deeper, but return the better solution

             else return (fin_tbl, upd_cmd_strs)

         else

             return (ini_tbl, cmd_strs))

-- | Main function.

main :: IO ()

main = do

  cmd_args <- System.getArgs

  (opts, args) <- CLI.parseOpts cmd_args "hbal" options

                  defaultOptions optShowHelp

  unless (null args) $ do

         hPutStrLn stderr "Error: this program doesn't take any arguments."

         exitWith $ ExitFailure 1

  when (optShowVer opts) $ do

         putStr $ CLI.showVersion "hbal"

         exitWith ExitSuccess

  (env_node, env_inst) <- CLI.parseEnv ()

  let nodef = if optNodeSet opts then optNodef opts

              else env_node

      instf = if optInstSet opts then optInstf opts

              else env_inst

      oneline = optOneline opts

      verbose = optVerbose opts

      (node_data, inst_data) =

          case optMaster opts of

            "" -> (readFile nodef,

                   readFile instf)

            host -> (readData getNodes host,

                     readData getInstances host)

  (loaded_nl, il, csf, ktn, kti) <- liftM2 Cluster.loadData node_data inst_data

  let (fix_msgs, fixed_nl) = Cluster.checkData loaded_nl il ktn kti

  unless (null fix_msgs) $ do

         putStrLn "Warning: cluster has inconsistent data:"

         putStrLn . unlines . map (\s -> printf "  - %s" s) $ fix_msgs

  let offline_names = optOffline opts

      all_names = snd . unzip $ ktn

      offline_wrong = filter (\n -> not $ elem n all_names) offline_names

      offline_indices = fst . unzip .

                        filter (\(_, n) -> elem n offline_names) $ ktn

  when (length offline_wrong > 0) $ do

         printf "Wrong node name(s) set as offline: %s\n"

                (commaJoin offline_wrong)

         exitWith $ ExitFailure 1

  let nl = Container.map (\n -> if elem (Node.idx n) offline_indices

                                then Node.setOffline n True

                                else n) fixed_nl

  when (Container.size il == 0) $ do

         (if oneline then

              printf "%.8f %d %.8f %8.3f\n"

                         (0::Double) (0::Integer) (0::Double) (1::Double)

          else

              printf "Cluster is empty, exiting.\n")

         exitWith ExitSuccess

  unless oneline $ printf "Loaded %d nodes, %d instances\n"

             (Container.size nl)

             (Container.size il)

  when (length csf > 0 && not oneline && verbose > 0) $ do

         printf "Note: Stripping common suffix of '%s' from names\n" csf

  let (bad_nodes, bad_instances) = Cluster.computeBadItems nl il

  unless (oneline || verbose == 0) $ printf

             "Initial check done: %d bad nodes, %d bad instances.\n"

             (length bad_nodes) (length bad_instances)

  when (length bad_nodes > 0) $ do

         putStrLn "Cluster is not N+1 happy, continuing but no guarantee \

                  \that the cluster will end N+1 happy."

  when (optShowNodes opts) $

       do

         putStrLn "Initial cluster status:"

         putStrLn $ Cluster.printNodes ktn nl

  let ini_cv = Cluster.compCV nl

      ini_tbl = Cluster.Table nl il ini_cv []

      min_cv = optMinScore opts

  when (ini_cv < min_cv) $ do

         (if oneline then

              printf "%.8f %d %.8f %8.3f\n"

                     ini_cv (0::Integer) ini_cv (1::Double)

          else printf "Cluster is already well balanced (initial score %.6g,\n\

                      \minimum score %.6g).\nNothing to do, exiting\n"

                      ini_cv min_cv)

         exitWith ExitSuccess

  unless oneline (if verbose > 1 then

                      printf "Initial coefficients: overall %.8f, %s\n"

                      ini_cv (Cluster.printStats nl)

                  else

                      printf "Initial score: %.8f\n" ini_cv)

  unless oneline $ putStrLn "Trying to minimize the CV..."

  let mlen_fn = maximum . (map length) . snd . unzip

      imlen = mlen_fn kti

      nmlen = mlen_fn ktn

  (fin_tbl, cmd_strs) <- iterateDepth ini_tbl (optMaxLength opts)

                         ktn kti nmlen imlen [] oneline min_cv

  let (Cluster.Table fin_nl _ fin_cv fin_plc) = fin_tbl

      ord_plc = reverse fin_plc

      sol_msg = if null fin_plc

                then printf "No solution found\n"

                else (if verbose > 1

                      then printf "Final coefficients:   overall %.8f, %s\n"

                           fin_cv (Cluster.printStats fin_nl)

                      else printf "Cluster score improved from %.8f to %.8f\n"

                           ini_cv fin_cv

                     )

  unless oneline $ putStr sol_msg

  unless (oneline || verbose == 0) $

         printf "Solution length=%d\n" (length ord_plc)

  let cmd_data = Cluster.formatCmds . reverse $ cmd_strs

  when (isJust $ optShowCmds opts) $

       do

         let out_path = fromJust $ optShowCmds opts

         putStrLn ""

         (if out_path == "-" then

              printf "Commands to run to reach the above solution:\n%s"

                     (unlines . map ("  " ++) .

                      filter (/= "check") .

                      lines $ cmd_data)

          else do

            writeFile out_path (CLI.shTemplate ++ cmd_data)

            printf "The commands have been written to file '%s'\n" out_path)

  when (optShowNodes opts) $

       do

         let (orig_mem, orig_disk) = Cluster.totalResources nl

             (final_mem, final_disk) = Cluster.totalResources fin_nl

         putStrLn ""

         putStrLn "Final cluster status:"

         putStrLn $ Cluster.printNodes ktn fin_nl

         when (verbose > 2) $

              do

                printf "Original: mem=%d disk=%d\n" orig_mem orig_disk

                printf "Final:    mem=%d disk=%d\n" final_mem final_disk

  when oneline $ do

         printf "%.8f %d %.8f %8.3f\n"

                ini_cv (length ord_plc) fin_cv (ini_cv / fin_cv)