Synnefo » snf-ganeti

{-| Cluster rebalancer

-}

{-

Copyright (C) 2009 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 Main (main) where

import Data.List

import Data.Function

import Data.Maybe (isJust, fromJust)

import Monad

import System

import System.IO

import qualified System

import Text.Printf (printf, hPrintf)

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Cluster as Cluster

import qualified Ganeti.HTools.Node as Node

import Ganeti.HTools.CLI

import Ganeti.HTools.Utils

-- | Options list and functions

options :: [OptType]

options =

    [ oPrintNodes

    , oPrintCommands

    , oOneline

    , oNodeFile

    , oInstFile

    , oRapiMaster

    , oLuxiSocket

    , oMaxSolLength

    , oVerbose

    , oQuiet

    , oOfflineNode

    , oMinScore

    , oMaxCpu

    , oMinDisk

    , oShowVer

    , oShowHelp

    ]

{- | 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

             -> 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 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_nl ini_il

                               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

                  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))

-- | Formats the solution for the oneline display

formatOneline :: Double -> Int -> Double -> String

formatOneline ini_cv plc_len fin_cv =

    printf "%.8f %d %.8f %8.3f" ini_cv plc_len fin_cv

               (if fin_cv == 0 then 1 else ini_cv / fin_cv)

-- | Main function.

main :: IO ()

main = do

  cmd_args <- System.getArgs

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

  unless (null args) $ do

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

         exitWith $ ExitFailure 1

  let oneline = optOneline opts

      verbose = optVerbose opts

  (fixed_nl, il, csf) <- loadExternalData opts

  let offline_names = optOffline opts

      all_nodes = Container.elems fixed_nl

      all_names = map Node.name all_nodes

      offline_wrong = filter (flip notElem all_names) offline_names

      offline_indices = map Node.idx $

                        filter (\n -> elem (Node.name n) offline_names)

                               all_nodes

      m_cpu = optMcpu opts

      m_dsk = optMdsk opts

  when (length offline_wrong > 0) $ do

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

                     (commaJoin offline_wrong)

         exitWith $ ExitFailure 1

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

                                then Node.setOffline n True

                                else n) fixed_nl

      nl = Container.map (flip Node.setMdsk m_dsk . flip Node.setMcpu m_cpu)

           nm

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

         (if oneline then putStrLn $ formatOneline 0 0 0

          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 > 1) $

       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) $

         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 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

              putStrLn $ formatOneline ini_cv 0 ini_cv

          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 > 2 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 imlen = Container.maxNameLen il

      nmlen = Container.maxNameLen nl

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

                         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 > 2

                     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

                              ::String

  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 (shTemplate ++ cmd_data)

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

  when (optShowNodes opts) $

       do

         let ini_cs = Cluster.totalResources nl

             fin_cs = Cluster.totalResources fin_nl

         putStrLn ""

         putStrLn "Final cluster status:"

         putStrLn $ Cluster.printNodes fin_nl

         when (verbose > 3) $

              do

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

                       (Cluster.cs_fmem ini_cs) (Cluster.cs_fdsk ini_cs)

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

                       (Cluster.cs_fmem fin_cs) (Cluster.cs_fdsk fin_cs)

  when oneline $

         putStrLn $ formatOneline ini_cv (length ord_plc) fin_cv