Backup Multiple MySQL Or MariaDB Databases Automatically

Introduction

In this write-up, we’ll walk through how to backup multiple MySQL or MariaDB databases that sit on the same machine using a custom bash script and setting up a cron job.

Database Backup(s)

We’ll assume we have three MySQL databases on our Vultr instance named db-vultr-site, db-vultr-blog, db-vultr-app (Don’t worry about creating these databases, you’ll be able to substitute their names for yours hwere they are used in the script on Step 2 below).

1. Log on to your MySQL or MariaDB database and run below query to create a database user db_user_backups to handle backups

   GRANT LOCK TABLES, SELECT, SHOW VIEW, REPLICATION CLIENT ON *.* TO 'db_user_backups'@'%' IDENTIFIED BY '{COMPLEX-PASSWORD}';
   

   Also run below to make sure MySQL is configured to properly restore stored procedures

   SET GLOBAL log_bin_trust_function_creators = 1;
   

2. Setup the necessarily directory structure and files needed

   # create backup directory with environment and log file
   sudo mkdir /backups && cd /backups
   sudo touch .env db-backup.sh db-backup.log
   sudo chmod -R 775 /backups
   sudo chmod -R g+s /backups
   sudo chmod +x db-backup.sh
   
   # add mysql backup user credentials into environment file
   echo "export MYSQL_USER=db_user_backups" > /backups/.env
   echo "export MYSQL_PASS={COMPLEX-PASSWORD}" >> /backups/.env
   

3. Open db-backup.sh nano /backups/db-backup.sh and paste the code below inside it, then save the file (Ctrl+X -> Y -> hit Enter).

   DB_NAMES=( 'db-vultr-site' 'db-vultr-blog' 'db-vultr-app' ) #replace with your own database name(s)
   BKUP_NAMES=()
   BKUP_DIR="/backups"
   
   # get total number of directories
   total_dbs=${#DB_NAMES[@]}
   
   # create backup file names
   for (( i=0; i<${total_dbs}; i++ )); do
       BKUP_NAMES[$i]="`date +%Y%m%d%H%M`-backup-$${DB_NAMES[$i]}.sql.gz"
   done
   
   # get backup users credentials
   source $BKUP_DIR/.env
   
   # create backups
   for (( i=0; i<${total_dbs}; i++ )); do
       # NOTE: --routines flag makes sure stored procedures are also backed up
       mysqldump --routines -u ${MYSQL_USER} -p${MYSQL_PASS} | gzip > ${BKUP_DIR}/${BKUP_NAMES[$i]}
   done
   

   The code above is looping through an array with the name(s) of the database(s) you want to backup and doing so.

Cronjob Setup

Setup a cronjob to run every midnight that runs the backup script and saves the result/output to backup log.

1. Open crontab

   crontab -e
   

2. Add below entry to crontab

   0 0 * * * /usr/bin/env bash /backups/db-backup.sh &>> /backups/db-backup.log
   

   Note: While testing you can set cronjob to run every 1 minute instead like below

   * * * * * /usr/bin/env bash /backups/db-backup.sh &>> /backups/db-backup.log
   

   -OR- every 5 minutes (replace 5 with the number of minutes you want)

   */5 * * * * /usr/bin/env bash /backups/db-backup.sh &>> /backups/db-backup.log
   

What’s Next

You will likely not want your backup(s) on the same server(s) running your database(s), but instead on a server in a different geographic location. There are several ways to do this, ranging from using SFTP, to using custom tools provided by the myriad of cloud storage providers available out there. One good alternative is Rsync as explained here – vultr.com/docs/setup-file-mirroring-using-rsync-in-debian-ubuntu

Written by Lami Adabonyan