4.3.5 Making a Partial Backup

Note

To facilitate the creation of partial backups, MySQL Enterprise Backup has introduced two new options for partial backup since version 3.10: --include-tables and --exclude-tables. The new options are intended for replacing the older options of --include, --databases, --databases-list-file, and --only-innodb-with-frm, which are incompatible with the new options and will be deprecated in the upcoming releases. In the discussions below we assume the new options are used for partial backups. For reference purpose, we have included information on the older options at the end of this section in Making a Partial Backup with Legacy Options.

By default, all the files under the database subdirectories in the data directory are included in the backup, so that the backup includes data from all MySQL storage engines, any third-party storage engines, and even any non-database files in that directory. This section explains options you can use to selectively back up or exclude data.

There are various ways to create different kinds of partial backup with MySQL Enterprise Backup:

• Including or excluding specific tables by their names. This uses the --include-tables or --exclude-tables option.

  Each table is checked against the regular expression specified with the --include-tables or --exclude-tables option. If the regular expression matches the fully qualified name of the table (in the form of db_name.table_name), the table is included or excluded for the backup. The regular expression syntax used is the extended form specified in the POSIX 1003.2 standard. The options have been implemented with the RE2 regular expression library.

• Including some or all InnoDB tables, but not other table types. This uses the --only-innodb option.

• Leaving out files that are present in the MySQL data directory but not actually part of the MySQL instance. This uses the --only-known-file-types option.

• Achieving a multiple of selection effects by using a combination of the above mentioned options.

• Backing up a selection of InnoDB tables using transportable tablespaces (TTS). This uses the --use-tts and the --include-tables or --exclude-tables (or both) options.

For syntax details on all the options involved, see Section 16.8, “Partial Backup and Restore Options”.

Important

Typically, a partial backup is more difficult to restore than a full backup, because the backup data might not include the necessary interrelated pieces to constitute a complete MySQL instance. In particular, InnoDB tables have internal IDs and other data values that can only be restored to the same instance, not a different MySQL server. Always fully test the recovery procedure for any partial backups to understand the relevant procedures and restrictions.

Important

Because the InnoDB system tablespace holds metadata about InnoDB tables from all databases in an instance, restoring a partial backup on a server that includes other databases could cause the system to lose track of those InnoDB tables in the other databases. Always restore partial backups on a fresh MySQL server instance without any other InnoDB tables that you want to preserve.

The following are some command samples for partial backups.

Including all tables with names starting with “emp” into the backup:

mysqlbackup \
 --host=localhost --user=mysqluser --protocol=TCP --port=3306 \
 --backup-dir=$MEB_TEMP_BACKUP_DIR --backup-image=$MEB_BACKUPS_DIR/my.mbi \
 --include-tables="\.emp" \
 backup-to-image

Taking a backup of all tables except tables from the “mysql” and “performance_schema” databases:

mysqlbackup \
 --host=localhost --user=mysqluser --protocol=TCP --port=3306 \
 --backup-dir=$MEB_TEMP_BACKUP_DIR --backup-image=$MEB_BACKUPS_DIR/my.mbi \
 --exclude-tables="^(mysql|performance_schema)\." \
 backup-to-image

Taking a backup of all tables in the “sales” database, but excludes the table with the name “hardware”

mysqlbackup \
 --host=localhost --user=mysqluser --protocol=TCP --port=3306 \
 ---backup-dir=$MEB_TEMP_BACKUP_DIR --backup-image=$MEB_BACKUPS_DIR/my.mbi \
 --include-tables="^sales\." --exclude-tables="^sales\.hardware$" \
 backup-to-image

Taking a backup of all tables in the “sales reps” database, but excludes the table with the name “euro-asia” (special characters like spaces or dashes are supported by the partial backup options since release 3.12.1):

mysqlbackup \
 --host=localhost --user=mysqluser --protocol=TCP --port=3306 \
 --backup-dir=$MEB_TEMP_BACKUP_DIR --backup-image=$MEB_BACKUPS_DIR/my.mbi \
 --include-tables="^sales reps\." --exclude-tables="^sales reps\.euro-asia" \
 backup-to-image

Backing up all InnoDB tables, but not .frm files:

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --only-innodb backup-to-image

You can also make compressed and other kinds of selective backups by using the appropriate command options.

Making a Partial Backup with the Legacy Options

Important

Information in this subsection is only for using the legacy options of --include, --databases, --databases-list-file, and --only-innodb-with-frm, which will be deprecated in the upcoming issues. For creating partial backups, it is strongly recommended that the new options of --include-tables and --exclude-tables be used instead. Note that you cannot combine the legacy and the new partial-backup options in a single command.

MySQL Enterprise Backup can make different kinds of partial backup using the legacy partial-backup options:

• Including certain InnoDB tables but not others. This operation involves the --include, --only-innodb, and --only-innodb-with-frm options.

• Including certain non-InnoDB tables from selected databases but not others. This operation involves the --databases and --databases-list-file options.

For syntax details on all these options, see Legacy Partial Backup Options.

Note

Typically, a partial backup is more difficult to restore than a full backup, because the backup data might not include the necessary interrelated pieces to constitute a complete MySQL instance. In particular, InnoDB tables have internal IDs and other data values that can only be restored to the same instance, not a different MySQL server. Always fully test the recovery procedure for any partial backups to understand the relevant procedures and restrictions.

With its --include option, mysqlbackup can make a backup that includes some InnoDB tables but not others:

• A partial backup with the --include option always contains the InnoDB system tablespace and all the tables inside it.

• For the InnoDB tables stored outside the system tablespace, the partial backup includes only those tables whose names match the regular expression specified with the --include option.

This operation requires the tables being left out to be stored in separate table_name.ibd files. To put an InnoDB table outside the system tablespace, create it while the innodb_file_per_table MySQL configuration option is enabled. Each .ibd file holds the data and indexes of one table only.

Those InnoDB tables created with innodb_file_per_table turned off are stored as usual in the InnoDB system tablespace, and cannot be left out of the backup.

For each table with a per-table data file a string of the form db_name.table_name is checked against the regular expression specified with the --include option. If the regular expression matches the complete string db_name.table_name, the table is included in the backup. The regular expression syntax used is the extended form specified in the POSIX 1003.2 standard. On Unix-like systems, quote the regular expression appropriately to prevent interpretation of shell meta-characters. This feature has been implemented with the RE2 regular expression library.

The backup directory produced contains a backup log file and copies of InnoDB data files.

IMPORTANT: Although mysqlbackup supports taking partial backups, be careful when restoring a database from a partial backup. mysqlbackup copies also the .frm files of those tables that are not included in the backup, except when you do partial backups using, for example, the --databases option. If you use mysqlbackup with the --include option, before restoring the database, delete from the backup data the .frm files for any tables that are not included in the backup.

IMPORTANT: Because the InnoDB system tablespace holds metadata about InnoDB tables from all databases in an instance, restoring a partial backup on a server that includes other databases could cause the system to lose track of those InnoDB tables in other databases. Always restore partial backups on a fresh MySQL server instance without any other InnoDB tables that you want to preserve.

The --only-innodb and --only-innodb-with-frm options back up InnoDB tables only, skipping those of other storage engines. You might also use them together with the --include option to make selective backup of InnoDB tables while excluding all other files created by other storage engines.

Example 4.23 Making an Uncompressed Partial Backup of InnoDB Tables

In this example, we have configured MySQL so that some InnoDB tables have their own tablespaces. We make a partial backup including only those InnoDB tables in test database whose name starts with ib. The contents of the database directory for test database are shown below. The directory contains a MySQL description file (.frm file) for each of the tables (alex1, alex2, alex3, blobt3, ibstest0, ibstest09, ibtest11a, ibtest11b, ibtest11c, and ibtest11d) in the database. Of these 10 tables six (alex1, alex2, alex3, blobt3, ibstest0, ibstest09) are stored in per-table data files (.ibd files).

$ ls /sqldata/mts/test
alex1.frm  alex2.ibd  blobt3.frm    ibstest0.ibd  ibtest11a.frm  ibtest11d.frm
alex1.ibd  alex3.frm  blobt3.ibd    ibtest09.frm  ibtest11b.frm
alex2.frm  alex3.ibd  ibstest0.frm  ibtest09.ibd  ibtest11c.frm

We run the mysqlbackup with the --include option:

# Back up some InnoDB tables but not any .frm files.
$ mysqlbackup --defaults-file=/home/dbadmin/my.cnf --include="^test\.ib.*" --only-innodb backup

# Contents in the backup directory's subdirectory for the test database:
$ ls /sqldata-backup/test
ibstest0.ibd   ibtest09.ibd

# Back up some InnoDB tables and the .frm files for the backed-up tables only.
$ mysqlbackup --defaults-file=/home/dbadmin/my.cnf --include="^test\.ib.*" \
  --only-innodb-with-frm=related backup

# Contents in the backup directory's subdirectory for the test database:
$ ls /sqldata-backup/test
ibstest0.frm   ibtest09.frm
ibstest0.ibd   ibtest09.ibd

The backup directory's subdirectory for the test database contains only backups of ibstest0 and ibtest09 tables, because other InnoDB tables do not match the include pattern ^test\.ib.*. The related .frm files are included in the second case. Notice that, however, the tables ibtest11a, ibtest11b, ibtest11c, ibtest11d are in the backup even though they are not visible in the directory shown below, because they are stored in the system tablespace (ibdata1 file) which is always included in the backup.

Example 4.24 Making a Compressed Partial Backup

We have configured MySQL so that every InnoDB table has its own tablespace. We make a partial backup including only those InnoDB tables whose name starts with alex or blob. The contents of the database directory for test database is shown below.

$ ls /sqldata/mts/test
alex1.frm  alex2.ibd  blobt3.frm    ibstest0.ibd  ibtest11a.frm  ibtest11d.frm
alex1.ibd  alex3.frm  blobt3.ibd    ibtest09.frm  ibtest11b.frm
alex2.frm  alex3.ibd  ibstest0.frm  ibtest09.ibd  ibtest11c.frm

We run mysqlbackup with the --compress and --include options:

$ mysqlbackup --defaults-file=/home/dbadmin/my.cnf --compress \
  --include=".*\.(alex|blob).*" --only-innodb backup

The backup directory for the database test is shown below. The .ibz files are compressed per-table data files.

$ ls /sqldata-backup/test
alex1.ibz   alex2.ibz   alex3.ibz   blobt3.ibz

The --databases and --databases-list-file options of mysqlbackup let you back up non-InnoDB tables only from selected databases, rather than across the entire MySQL instance. (To filter InnoDB tables, use the --include option instead.) With --databases, you specify a space-separated list of database names, with the entire list enclosed in double quotation marks. With --databases-list-file, you specify the path of a file containing the list of database names, one per line.

Some or all of the database names can be qualified with table names, to only back up selected non-InnoDB tables from those databases.

If you specify this option, make sure you include the same set of databases for every backup (especially incremental backups), so that you do not restore out-of-date versions of any databases.