My plugin for checking a redis server (free mem, frag ratio, last save)

check_redis

#!/bin/bash

#   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; version 2 of the License only.
#
#   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 St, Fifth Floor, Boston, MA  02110-1301  USA

PROGNAME=`basename $0`
AUTHOR="Arsenio Santos"

usage(){
        echo $PROGNAME $VERSION
        echo
        echo Check the local Redis instance
        echo
        echo OPTIONS:
        echo  -h Shows this help
        echo  -w sets the memory utilization warning level
        echo  -c sets the memory utilization critical level
        echo  -r sets the memory fragmentation ratio critical level
        echo  -l sets the last save time critical limit in seconds 
}

MEMWARN=50      # 50% system memory
MEMCRIT=75      # 75% system memory
MEMRATIO=2.0    # 2.0 ratio
LASTSAVE=604800 # 1 week


while getopts "hvw:c:r:l:" opt; do
  case $opt in
    h)
      usage
      exit
      ;;
    w)
      MEMWARN=$OPTARG
      ;;
    c)
      MEMCRIT=$OPTARG
      ;;
    r)
      MEMRATIO=$OPTARG
      ;;
    l)
      LASTSAVE=$OPTARG
      ;;

    \?)
      usage
      exit
      ;;

    :)
      echo "Option -$OPTARG requires an argument." >&2
      exit 1
      ;;
  esac
done

if [ ${MEMWARN} -gt ${MEMCRIT} ]
then
    echo "Your warning level cannot be higher than your critical level."
    exit 1
fi

if [ "$MEMWARN" -lt 0 -o "$MEMWARN" -gt 100 -o "$MEMCRIT" -lt 0 -o "$MEMCRIT" -gt 100 ]
then
    echo "Warning and critical levels must be integers between 0 and 100."
    exit 2
fi

STAT_MEM_FRAG_RATIO="null"
STAT_USED_MEMORY="null"
STAT_LAST_SAVE_TIME="null"
DATA=`redis-cli info`
for stat in $DATA
do
    IFS=":" read -ra DATUM <<< "$stat"
    case "${DATUM[0]}" in
      mem_fragmentation_ratio)
        STAT_MEM_FRAG_RATIO=`echo ${DATUM[1]} | sed -e 's/[^0-9\.]//g'`
        ;;
      used_memory)
        STAT_USED_MEMORY=`echo ${DATUM[1]} | sed -e 's/[^0-9\.]//g'`
        ;;
      last_save_time)
        STAT_LAST_SAVE_TIME=`echo ${DATUM[1]} | sed -e 's/[^0-9\.]//g'`
        ;;
    esac
done

TOTAL_MEMORY=`free -b | grep Mem: | sed -e 's/^Mem: *\([0-9]*\) *.*$/\1/'`
STAT_MEM_PCT=$(echo "$STAT_USED_MEMORY*100.0/$TOTAL_MEMORY" | bc)
RATIO_EXCEEDED=$(echo "${STAT_MEM_FRAG_RATIO} > ${MEMRATIO}" | bc)
CURRENT_TIMESTAMP=`date +"%s"`
LAST_SAVE_AGE=$(echo "$CURRENT_TIMESTAMP - $STAT_LAST_SAVE_TIME" | bc)

if [ ${STAT_MEM_PCT} -ge ${MEMWARN} -a ${STAT_MEM_PCT} -lt ${MEMCRIT} ]
then
    echo "WARNING - Used: $STAT_USED_MEMORY (${STAT_MEM_PCT}%) | Frag Ratio: $STAT_MEM_FRAG_RATIO, Last Save: $LAST_SAVE_AGE secs ago"
    exit $ST_WR
elif [ ${STAT_MEM_PCT} -ge ${MEMCRIT} ]
then
    echo "CRITICAL - Used: $STAT_USED_MEMORY (${STAT_MEM_PCT}%) | Frag Ratio: $STAT_MEM_FRAG_RATIO, Last Save: $LAST_SAVE_AGE secs ago"
    exit $ST_CR
elif [ ${RATIO_EXCEEDED} -eq 1 ]
then
    echo "CRITICAL - Frag Ratio: $STAT_MEM_FRAG_RATIO | Used: $STAT_USED_MEMORY (${STAT_MEM_PCT}%), Last Save: $LAST_SAVE_AGE secs ago"
    exit $ST_CR
elif [ ${LAST_SAVE_AGE} -ge ${LASTSAVE} ]
then
    echo "CRITICAL - Last Save: $LAST_SAVE_AGE secs ago | Used: $STAT_USED_MEMORY (${STAT_MEM_PCT}%), Frag Ratio: $STAT_MEM_FRAG_RATIO"
    exit $ST_CR
else
    echo "OK - Used: $STAT_USED_MEMORY (${STAT_MEM_PCT}%), Frag Ratio: $STAT_MEM_FRAG_RATIO, Last Save: $LAST_SAVE_AGE secs ago"
    exit $ST_OK
fi