bin/rebalance-shuffle.sh

   1 #!/bin/bash -e
   2
   3 #
   4 #   Copyright 2013 LinkedIn, Inc
   5 #
   6 #  Licensed under the Apache License, Version 2.0 (the "License");
   7 #  you may not use this file except in compliance with the License.
   8 #  You may obtain a copy of the License at
   9 #
  10 #      http://www.apache.org/licenses/LICENSE-2.0
  11 #
  12 #  Unless required by applicable law or agreed to in writing, software
  13 #  distributed under the License is distributed on an "AS IS" BASIS,
  14 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15 #  See the License for the specific language governing permissions and
  16 #  limitations under the License.
  17
  18 # This script shuffles a current cluster.xml (to achieve a more balanced cluster) and then
  19 # outputs a final-cluster.xml corresponding to it. It also outputs the plan and the cost
  20 # to achieve this final cluster config. Eg.
  21 #
  22 # Argument = -c current_cluster -s current_stores -o output dir
  23 # The final cluster is placed in output_dir/
  24 #
  25 # The script also exposes an optional argument -m <max contiguous partitons>.
  26 # When invoked with the -m option the script first splits runs of partition that are bigger than
  27 # <max contiguous partitons> and then repartitions the cluster.
  28 #
  29 # Eg. Argument = -c current_cluster -s current_stores -o output dir -m 3
  30 #
  31 # This script can be used again on its own output. That is, if first attempt only gets you half-way
  32 # to where you want to go in terms of repartitioning, then take output final-cluster xml and use as
  33 # input to this tool again.
  34 #
  35 # This script uses getopts which means only single character switches are allowed.
  36 # Using getopt would allow for multi charcter switch names but would come at a
  37 # cost of not being cross compatible.
  38
  39 # Function to display usage
  40 usage_and_exit() {
  41   echo "ERROR: $1."
  42   cat <<EOF
  43
  44   Usage: $0 options
  45   OPTIONS:
  46    -h     Show this message
  47    -c     Current cluster that describes the cluster.
  48    -s     Current stores that describes the store. If you do not have info about the stores yet, look
  49           under 'voldemort_home/config/tools/' for some store examples.
  50    -o     Output dir where all interim and final files will be stored.
  51           The directory will be created if it does not exist yet.
  52    -m     Max allowed contiguous partition IDs within a zone (optional argument)
  53 EOF
  54 exit 1
  55 }
  56
  57 # initialize  variables
  58 current_cluster=""
  59 current_stores=""
  60 output_dir=""
  61 max_contiguous_partitions=-1
  62
  63 # Figure out voldemort home directory
  64 dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
  65 vold_home="$(dirname "$dir")"
  66
  67 # Parse options
  68 while getopts “hc:s:o:m:” OPTION
  69 do
  70   case $OPTION in
  71   h)
  72     usage_and_exit
  73     exit 1
  74     ;;
  75   c)
  76     current_cluster=$OPTARG
  77     echo "[rebalance-shuffle] Will rebalance on the cluster described in '$current_cluster'."
  78     ;;
  79   s)
  80     current_stores=$OPTARG
  81     echo "[rebalance-shuffle] Will rebalance on the stores described in '$current_stores'."
  82     ;;
  83   o)
  84     output_dir=$OPTARG
  85     mkdir -p $output_dir
  86     echo "[rebalance-shuffle] Using '$output_dir' for all interim and final files generated."
  87     ;;
  88   m)
  89     max_contiguous_partitions=$OPTARG
  90     echo "[rebalance-shuffle] Using '$max_contiguous_partitions' for max_contiguous_partitions."
  91     ;;
  92   ?)
  93     usage_and_exit
  94   ;;
  95      esac
  96 done
  97
  98 if [[ -z $current_cluster ]] || [[ -z $current_stores ]] || [[ -z $output_dir ]]
  99 then
 100      printf "\n"
 101      echo "[rebalance-shuffle] Missing argument. Check again."
 102      usage_and_exit
 103      exit 1
 104 fi
 105
 106 if [ ! -e $current_cluster ]; then
 107     usage_and_exit "File '$current_cluster' does not exist."
 108 fi
 109
 110 if [ ! -e $current_stores ]; then
 111     usage_and_exit "File '$current_stores' does not exist."
 112 fi
 113
 114 # The final cluster.xml after shuffling is generated as described in the steps below:
 115 # Step 0 : This step is executed only if the max_contiguous_partitions is passed to the
 116 #          script. In this step, lengthy runs of contiguous partitions are broken down
 117 #          to a maximum run of max_contiguous_partitions value. The final-cluster.xml
 118 #          from this step is then fed into step 1.
 119 # Step 1: Current cluster.xml is fed to the repartitioner along with random swap
 120 #         attempts. The repartitioner randomly swaps the partitions
 121 #         and tries to balance the ring.
 122 # Step 2: A plan is generated on how to reach from the orignal cluster topology to
 123 #         the one that is generated in step 1.
 124 #
 125 swap_attempts=250
 126 max_contiguous_attempts=50
 127 attempts=10
 128 swap_successes=250
 129
 130 # Step 0
 131 if [ "$max_contiguous_partitions" -ne "-1" ]; then
 132   mkdir -p $output_dir/step0/
 133   $vold_home/bin/run-class.sh voldemort.tools.RepartitionerCLI \
 134                             --current-cluster $current_cluster \
 135                             --current-stores $current_stores \
 136                             --max-contiguous-partitions $max_contiguous_partitions \
 137                             --attempts $max_contiguous_attempts \
 138                             --output-dir $output_dir/step0/
 139
 140   if [ ! -e $output_dir/step0/final-cluster.xml ]; then
 141     usage_and_exit "File '$final-cluster.xml' does not exist."
 142   fi
 143
 144   current_cluster=$output_dir/step0/final-cluster.xml
 145   echo "[rebalance-shuffle] Will rebalance on the cluster in '$current_cluster'."
 146 fi
 147
 148 # Step 1
 149 mkdir -p $output_dir/step1
 150 $vold_home/bin/run-class.sh voldemort.tools.RepartitionerCLI \
 151                             --current-cluster $current_cluster \
 152                             --current-stores $current_stores \
 153                             --output-dir $output_dir/step1/ \
 154                             --enable-random-swaps \
 155                             --attempts $attempts \
 156                             --random-swap-attempts $swap_attempts \
 157                             --random-swap-successes $swap_successes
 158
 159 if [ ! -e $output_dir/step1/final-cluster.xml ]; then
 160     usage_and_exit "File '$final-cluster.xml' does not exist."
 161 fi
 162
 163 # Step 2
 164 mkdir -p $output_dir/step2/
 165 $vold_home/bin/run-class.sh voldemort.tools.RebalancePlanCLI \
 166                             --current-cluster $current_cluster \
 167                             --current-stores $current_stores \
 168                             --final-cluster $output_dir/step1/final-cluster.xml \
 169                             --output-dir $output_dir/step2/
 170
 171 echo "[rebalance-shuffle] Placing final-cluster.xml in '$output_dir'"
 172 cp $output_dir/step2/final-cluster.xml $output_dir/final-cluster.xml
 173 echo "[rebalance-shuffle] Placing plan.out in '$output_dir'"
 174 cp $output_dir/step2/plan.out $output_dir/plan.out
 175 echo "[rebalance-shuffle] Placing final-cluster.xml.analysis in '$output_dir'"
 176 cp $output_dir/step1/final-cluster.xml.analysis $output_dir/final-cluster.xml.analysis