Connection and privileges needed¶
Percona XtraBackup needs to be able to connect to the database server and perform operations on the server and the datadir when creating a backup, when preparing in some scenarios and when restoring it. In order to do so, there are privileges and permission requirements on its execution that must be fulfilled.
Privilege refers to the operations that a system user is permitted to do in the database server. They are set at the database server and only apply to users in the database server.
Permissions are those which permits a user to perform operations on the system, like reading, writing or executing on a certain directory or start/stop a system service. They are set at a system level and only apply to system users.
When xtrabackup is used, there are two actors involved: the user invoking the program - a system user - and the user performing action in the database server - a database user. Note that these are different users in different places, even though they may have the same username.
All the invocations of xtrabackup in this documentation assume that the system user has the appropriate permissions, and you are providing the relevant options for connecting the database server - besides the options for the action to be performed - and the database user has adequate privileges.
Connect to the server¶
The database user used to connect to the server and its password are specified
by the --user
and --password
option:
$ xtrabackup --user=DVADER --password=14MY0URF4TH3R --backup \
--target-dir=/data/bkps/
If you don’t use the --user
option, Percona XtraBackup will assume
the database user whose name is the system user executing it.
Other connection options¶
According to your system, you may need to specify one or more of the following options to connect to the server:
Option | Description |
---|---|
-port | Use this port when connecting to the database with TCP/IP |
-socket | Use this socket when connecting to the local database. |
-host | Use this host when connecting to the database server with TCP/IP |
These options are passed to the mysql child process without
alteration, see mysql --help
for details.
Note
In case of multiple server instances, the correct connection parameters (port, socket, host) must be specified in order for xtrabackup to talk to the correct server.
Privileges needed¶
Once connected to the server, in order to perform a backup you need
READ
and EXECUTE
permissions at a filesystem level in the server’s datadir.
The database user needs the following privileges to back up tables or databases:
-
RELOAD
andFLUSH_TABLES
in order to runFLUSH TABLES WITH READ LOCK
. -
The
BACKUP_ADMIN
privilege is needed to query the performance_schema.log_status table, and runLOCK INSTANCE FOR BACKUP
,LOCK BINLOG FOR BACKUP
, orLOCK TABLES FOR BACKUP
. TheBACKUP_ADMIN
privilege is required to use the Page tracking feature. -
REPLICATION CLIENT
in order to obtain the binary log position, -
CREATE TABLESPACE
in order to import tables (see Restoring Individual Tables), -
PROCESS
in order to runSHOW ENGINE INNODB STATUS
(which is mandatory), and optionally to see all threads which are running on the server (see FLUSH TABLES WITH READ LOCK option), -
REPLICATION_SLAVE_ADMIN
in order to start/stop the replication threads in a replication environment, -
CREATE
privilege in order to create the PERCONA_SCHEMA.xtrabackup_history database and table, -
ALTER
privilege in order to upgrade the PERCONA_SCHEMA.xtrabackup_history database and table, -
INSERT
privilege in order to add history records to the PERCONA_SCHEMA.xtrabackup_history table, -
SELECT
privilege in order to use--incremental-history-name
or--incremental-history-uuid
in order for the feature to look up theinnodb_to_lsn
values in the PERCONA_SCHEMA.xtrabackup_history table. -
SELECT
privilege on the keyring_component_status table to view the attributes and status of the installed keyring component when in use. -
SELECT
privilege on the replication_group_members table to validate if the instance is part of group replication cluster.
A SQL example of creating a database user with the minimum privileges required to take full backups would be:
mysql> CREATE USER 'bkpuser'@'localhost' IDENTIFIED BY 's3cr%T';
mysql> GRANT BACKUP_ADMIN, PROCESS, RELOAD, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'bkpuser'@'localhost';
mysql> GRANT SELECT ON performance_schema.log_status TO 'bkpuser'@'localhost';
mysql> GRANT SELECT ON performance_schema.keyring_component_status TO bkpuser@'localhost';
mysql> GRANT SELECT ON performance_schema.replication_group_members TO bkpuser@'localhost';
mysql> FLUSH PRIVILEGES;
Query the privileges¶
To query the privileges that your database user has been granted at the console of the server execute:
mysql> SHOW GRANTS;
or for a particular user with:
mysql> SHOW GRANTS FOR 'db-user'@'host';
It will display the privileges using the same format as for the GRANT statement.
Note that privileges may vary across versions of the server. To list the exact list of privileges that your server support (and a brief description of them) execute:
mysql> SHOW PRIVILEGES;
See also
Get expert help¶
If you need assistance, visit the community forum for comprehensive and free database knowledge, or contact our Percona Database Experts for professional support and services.