如何使用shellscript为mysql获取增量备份

Question

here the given below code it's correctly worked for backup but i need to change incremental backup. i want to take backup every 4 hour. how to set time schedular in shell script ?

#!/bin/bash

    TIMESTAMP=$(date +"%F")
    BACKUP_DIR="/home/admin/$TIMESTAMP"
    MYSQL_USER="test"
    MYSQL=/usr/bin/mysql
    MYSQL_PASSWORD="******"
    MYSQLDUMP=/usr/bin/mysqldump

    mkdir -p "$BACKUP_DIR/mysql"

    databases=`$MYSQL --user=$MYSQL_USER -p$MYSQL_PASSWORD -e "SHOW DATABASES;" | grep -Ev "(Database|information_schema|performance_schema)"`

    for db in $databases; do
      $MYSQLDUMP --force --opt --user=$MYSQL_USER -p$MYSQL_PASSWORD --databases $db | gzip > "$BACKUP_DIR/mysql/$db.gz"
    done

Answer 1

Take a look into mysql binary logs. Basically two steps have to be done

1. create mysqldump
2. copy binarylog that has all changes after the last mysqldump

mysqldump provides you a full backup. The binary log all the changes that happened. That is the closest that comes to "incremental" backups in mysql.

See http://dev.mysql.com/doc/refman/5.5/en/binary-log.html for more details. Be aware that you want --master-data flag for the mysqldump, else you don't know where to start in the binary log.