mtds/mysql_backup_script

Shell script wrappers over Percona xtrabackup tool

Wrapper script over Percona xtrabackup

The main purpose of this shell script is to provide a wrapper over the Xtrabacup tool from Percona. It provides an easy way to have a full and incremental backups from a MySQL instance.

It was mainly tested on Debian based Linux distributions.

Scipts provided:

• innobackupex-runner.sh: full/incremental MySQL backups.
• innobackupex-restore.sh: restore script (Note: it is intended to be executed interactively).

How it works

innobackupex-runner.sh can read a configuration file in INI format (see example under the etc subdirectory of this repo or it can be used interactively through multiple command line options. Note that this script has to be executed with root privileges.

If a configuration file is present, the only mandatory option on the command line is -d which is used to specify where is the directory to store the backup files.

In the configuration file the two most important entries are mycnf (which points to a MySQL configuration file, e.g. under /etc/mysql/my.cnf) and cnfauth which points to configuration file which contains the username and password used to connect to a MySQL instance. In the example used in this repo, it points to /etc/mysql/debian.cnf which contains the credentials of special user defined on default installation of MySQL under Debian. Of course, it is always possible to define your own config files.

Command Line Options

The following is a complete list of the cmd line options for the backup script:

• -d Directory used to store database backup
• -a Path of a CNF file containing admin credentials
• -f Path to my.cnf database config file
• -g Group to read from the config file
• -u Username used when connecting to the database
• -p Password used when connecting to the database
• -i Username/Password will be provided on the cmd line
• -H Host used when connecting to the database
• -P Port number used when connecting to the database
• -S Socket used when connecting to the database
• -v Verbose mode: print more output messages
• -h Display basic help

Origin of this script

This script is originally derived from the one available through this Github gist.

I have made by myself the following modifications:

• Default shell changed to /bin/bash.
• Renamed some variables.
• All the external commands are invoked with the full path.
• Splitted the script logic in multiple functions.

Plus the following enhancements were not present in the original version:

• Parameters can be read from a config file (through an INI parser).
• Check if there's enough free disk space before starting the backup.
• Logging: when the script is not used interactively all the output/error messages are logged into a file.

The copyright of the original developers is reported here and also on the script itself:

• (C)2010 Owen Carter @ Mirabeau BV
• (C)2013 Benoit LELEVE' @ Exsellium (www.exsellium.com)

In order to read an INI configuration file, this repository is also including the extremely useful INI Parser from Ruediger Meier, which is available through this Github repo.

Define a CRON entry

Run the script every four hours after defining an entry under /etc/cron.d:

#
# Make MySQL backups (full/incremental) every four hours:
#
0 */4 * * * root /usr/bin/innobackupex-runner.sh -d /opt/db_backups