Holland Config Files

By default, Holland’s configuration files reside in /etc/holland. The main configuration file is holland.conf, however there are a number of other configuration files for configuring default settings for providers and for configuring backup sets.

Each configuration file has one ore more sections, defined by square brackets Underneath each section, one or more configuration option can be specified. These options are in a standard “option = value” format. Comments are prefixed by the # sign.

Note that many settings have default values and, as a result, can either be commented out or omitted entirely.

holland.conf - main config

The main configuration file (usually /etc/holland/holland.conf) defines both global settings as well as the active backup sets. It is divided into two sections [holland] and [logging].

[holland]

plugin-dirs

Defines where the plugins can be found. This can be a comma-separated list but usually does not need to be modified.

backup_directory

Top-level directory where backups are held.

backupsets

A comma-separated list of all the backup sets Holland should backup. Each backup set is defined in /etc/holland/backupsets/<name>.conf by default.

umask

Sets the umask of the resulting backup files.

path

Defines a path for holland and its spawned processes

[logging]

filename

The log file itself.

level

Sets the verbosity of Holland’s logging process. Available options are debug, info, warning, error, and critical

format

Define the format of the log message. This options should be in the format defined by the ‘logging’ python library.

New in version 1.1.0.

Provider Configs

These files control the global settings / defaults for the providers used by the backup-sets. Many of these global settings can be overridden if defined in a backup-set. Note that each provider’s configuration file should begin with [provider-name].

Backup-Set Configs

Backup-Set configuration files largely inherit the configuration options of the specified provider. To define a provider for the backup set, you must put the following at the top of the backup set configuration file:

[holland:backup]
plugin = <plugin>
backups-to-keep = #
estimated-size-factor = #
historic-size = <yes|no>
historic-size-factor = #
historic-estimated-size-factor = #

Configuration Options

plugin = <plugin>

This is the name of the provider that will be used for the backup-set. This is required in order for the backup-set to function.

backups-to-keep = #

Specifies the number of backups to keep for a backup-set. Defaults to retaining 1 backup.

estimated-size-factor = #

Specifies the scale factor when Holland decides if there is enough free space to perform a backup. The default is 1.0 and this number is multiplied against what each individual plugin reports its estimated backup size when Holland is verifying sufficient free space for the backupset.

As of Holland 1.1.1, the ‘historic’ backup size will be used. If Holland is unable to determine that size, it will default back to this.

auto-purge-failures = yes | no

Specifies whether to keep a failed backup or to automatically remove the backup directory. By default this is on with the intention that whatever process is calling holland will retry when a backup fails. This behavior can be disabled by setting auto-purge-failures = no when partial backups might be useful or when troubleshooting a backup failure.

purge-policy = manual | before-backup | after-backup

Specifies when to run the purge routine on a backupset. By default this is run after a new successful backup completes. Up to backups-to-keep backups will be retained including the most recent.

purge-policy = before-backup will run the purge routine just before a new backup starts. This will retain up to backups-to-keep backups before the new backup is even started allowing purging all previous backups if backups-to-keep is set to 0. This behavior is useful if some other process is retaining backups off-server and disk space is at a premium.

purge-policy = manual will never run the purge routine automatically. Either holland purge must be run externally or an explicit removal of desired backup directories can be done at some later time.

before-backup-command = string

Run a shell command before a backup starts. This allows a command to perform some action before the backup starts such as setting up an iptables rule (taking a mysql slave out of a load balancer) or aborting the backup based on some external condition.

The backup will fail if this command exits with a non-zero status.

New in version 1.0.7.

after-backup-command = string

Run a shell command after a backup completes. This allows a command to perform some action when a backup completes successfully such as sending out a success notification.

The backup will fail if this command exits with a non-zero status.

New in version 1.0.7.

failed-backup-command = string

Run a shell command if a backup starts. This allows some command to perform some action when a backup fails such as sending out a failure notification.

The backup will fail if this command exits with a non-zero status.

New in version 1.0.7.

historic-size = yes | no

Defaults to yes. Check for the ‘backup.conf’ file in the ‘newest’ spooled folder for the running “backupset”. If the configuration file exists and contains ‘estimated-size’ and ‘on-disk-size’, these values will be used to decide if holland has enough free space for a backupset. This means Holland will use values from the previous backup to estimate the size of the next backup.

New in version 1.1.1.

historic-size-factor = #

Defaults to ‘1.5’. If the estimated size of the database has changed by more than this multiple, the ‘estimated-size-factor’ value will be used to determine if there is sufficient free space for the backupset.

New in version 1.1.1.

historic-estimated-size-factor = #

Defaults to ‘1.1’. Specifies the scale factor when Holland decides if there is enough free space to perform a backup. Holland will throw an error if the system has less free space than the last backup size multiplied by this value

New in version 1.1.1.

create-symlinks = yes | no

Defaults to yes. Enable the creation of “newest” and “oldest” symlinks in the backupset directory. Disabling the symlink creation process and be helpful on filesystems that don’t support symlinks.

New in version 1.2.7.

$ ls -l /var/spool/holland/default/
total 0
drwxrwx---. 3 root root 58 Aug 18 16:18 20210818_161856
lrwxrwxrwx. 1 root root 42 Aug 18 16:18 newest -> /var/spool/holland/default/20210818_161856
lrwxrwxrwx. 1 root root 42 Aug 18 16:18 oldest -> /var/spool/holland/default/20210818_161856

For all hook commands, Holland will perform simple text substitution on the three parameters:

  • hook - name of the hook being called (one of: before-backup-command, after-backup-command, failed-backup-command)
  • backupdir - path to the current backup directory (e.g. /var/spool/holland/mysqldump/YYYYmmdd_HHMMSS)
  • backupset - name of the backupset being run (e.g. ‘mysql-lvm’)

For example:

[holland:backup]
plugin = mysqldump
before-backup-command = /usr/local/bin/my-custom-script --hook ${hook} --backupset ${backupset} --backupdir ${backupdir}
after-backup-command = echo ${backupset} completed successfully.  Files are in ${backupdir}

[mysqldump]
...

Backup-Set files are defined in the “backupsets” directory which is, by default, /etc/holland/backupsets. The name of the backup-set is defined by its configuration filename and can really be most anything. That means backup-sets can be organized in any arbitrary way, although backup set files must end in .conf. The file extension is not part of the name of the backup-set.

As noted above, in order for a backup-set to be active, it must be listed in the backupsets variable.

Backups are placed under the directory defined in the backup_directory section of the main configuration file. Each backup resides under a directory corresponding to the backup-set name followed by a date-encoded directory.