Mongo Monitor Script: Health Check

Description

The Script will search for any working server listed in the mongo.properties. It executes the rs.status() command and check the health of all the server in replication

Step to configure mongo.properties

In mongo.properties we need to set the below properties

<!--[if !supportLists]-->· <!--[endif]-->USERNAME [mongo database user's username]

<!--[if !supportLists]-->· <!--[endif]-->PASSWORD [Password]

<!--[if !supportLists]-->· <!--[endif]-->MONGO_INSTALL_BIN_DIR [Mongo installed bin directory]

<!--[if !supportLists]-->· <!--[endif]-->HOSTNAME [List of all servers (get it by execute rs.status() command on mongo client) separated with ;]

<!--[if !supportLists]-->· <!--[endif]-->DEFAULT_HOST_PORT [Default server setting for health check]

USERNAME=username

PASSWORD=password

MONGO_INSTALL_BIN_DIR=/usr/local/mongo/bin/

DEFAULT_HOST_PORT=hostname:27017

HOSTNAME="host1:27017;host2:27017;host3:27017"

Step to configure mongo-health-chk.sh

Open the mongo-health-chk.sh and correct the path for the mongo.properties

For e.g. . /usr/local/mongo.properties

Setting the CRON job

To execute the script as cron job, run below command on shell prompt

#crontab -e

This will open the cron job file. Make an entry of below cron expression [update the script location path]. This will run the script in every 5 min. you need to pass the log file name/path as parameter while running this script

*/5 0 * * * /path/to/script/mongo-health-chk.sh mongo_health.log

Below is the script

#!/bin/bash

. /home/mongo/mongo.properties

exec >> $1

#################################################################

# CHECK THE HEALTH OF ALL SERVER IN REPLICATION #

# version:- 1.0 #

# Author:- Chandrashekhar Dehankar #

# THIS SCRIPT WILL SEARCH OUT FOR ANY WORKING SERVER LISTED #

# IN mongo.properties. EXECUTES THE rs.status() COMMAND AND #

# */5 * * * * /home/mongo/mongo-health-chk.sh health.log #

# CRON EXPRESSION EVERY 5MIN IS BELOW #

#################################################################

#DATABASE HOST-PORT DEFAULT SETTING

HOST_PORT=$DEFAULT_HOST_PORT

#METHOD TO CHECK SERVER HEALTH

function _do_health_check {

#FIND ANY WORKING SERVER

DATABASE_HOST_SERVER=$HOSTNAME

DATABASE_HOST_SERVER=${DATABASE_HOST_SERVER//;/$'\n'}

for host in $DATABASE_HOST_SERVER

do

#CHECK WEATHER ITS IS UP OR NOT WHAT, NO MATTERS PRIMARY OR SECONDARY

IS_SERVER_UP=$($MONGO_INSTALL_BIN_DIR/mongo $host/admin -u $USERNAME -p $PASSWORD --eval "printjson(db.isMaster().secondary)" )

#FILTER THE RESULT

IS_SERVER_UP=`echo $IS_SERVER_UP grep -o '[^ ]*$'`

if [ "$IS_SERVER_UP" == "true" ] [ "$IS_SERVER_UP" == "false" ]; then

HOST_PORT=$host

break

fi

done

count=0

CURRENT_DATE=`date +%Y%m%d_%H-%M-%S`

echo "--------HEALTH TEST START[$CURRENT_DATE] ----------"

while [ $count -ne -1 ]

do

HOST_NAME=$($MONGO_INSTALL_BIN_DIR/mongo $HOST_PORT/admin -u $USERNAME -p $PASSWORD --eval "printjson(rs.status().members[$count].name)" )

HOST_NAME=`echo $HOST_NAME grep -o '[^ ]*$'`

CHECK_HEALTH=$($MONGO_INSTALL_BIN_DIR/mongo $HOST_PORT/admin -u $USERNAME -p $PASSWORD --eval "printjson(rs.status().members[$count].health)" )

CHECK_HEALTH=`echo $CHECK_HEALTH grep -o '[^ ]*$'`

count=$(( $count + 1 ))

#CHECK ALL THE NODES IN REPLICATION

if [ "$CHECK_HEALTH" != "1" ] && [ "$CHECK_HEALTH" != "0" ]; then

echo "..........All SERVER HEALTH TEST DONE.........."

count="-1"

fi

if [ $count -ne -1 ]; then

echo "----------------------------------------------------------"

if [ "$CHECK_HEALTH" == "1" ]; then

echo $HOST_NAME IS WORKING FINE

else

echo $HOST_NAME IS DOWN

fi

echo "----------------------------------------------------------"

fi

done

}

## check the health

_do_health_check