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MariaDB/MySQL (Database service)
mysql
Services
2021-06-03

Last updated 3rd June 2021

Objective

Web PaaS supports both MariaDB and Oracle MySQL. While there are some differences at the application level for developers, they function nearly identically from an infrastructure point of view.

See the MariaDB documentation or MySQL documentation for more information.

Supported versions

The service types mariadb and mysql both refer to MariaDB for compatibility reasons. The service type oracle-mysql refers to MySQL as released by Oracle, Inc. Other than the type, MySQL and MariaDB are otherwise identical and the rest of this page refers to both equally.

mariadb mysql oracle-mysql
- 5.7
  • 8.0 |

Only MariaDB is available on Dedicated environments, using Galera for replication:

  • 10.0
  • 10.1
  • 10.2
  • 10.3
  • 10.4
  • 10.5

[!primary]
Downgrades of MySQL or MariaDB are not supported. Both will update their own datafiles to a new version automatically but cannot downgrade them. If you want to experiment with a later version without committing to it use a non-master environment.

Dedicated environments do not support any storage engine other than InnoDB. Tables created using the MyISAM storage engine on dedicated environments will not replicate between cluster nodes.

Deprecated versions

The following versions are available but are not receiving security updates from upstream, so their use is not recommended. They will be removed at some point in the future.

mariadb mysql oracle-mysql

Relationship

The format exposed in the $PLATFORM_RELATIONSHIPS environment variable:

{
    "username": "user",
    "scheme": "mysql",
    "service": "mariadb104",
    "fragment": null,
    "ip": "169.254.135.53",
    "hostname": "e3wffyxtwnrxujeyg5u3kvqi6y.mariadb104.service._.eu-3.platformsh.site",
    "public": false,
    "cluster": "rjify4yjcwxaa-master-7rqtwti",
    "host": "mysql.internal",
    "rel": "mysql",
    "query": {
        "is_master": true
    },
    "path": "main",
    "password": "",
    "type": "mariadb:10.4",
    "port": 3306,
    "host_mapped": false
}

Usage example

For MariaDB your .platform/services.yaml use mariadb service type:

db:
    type: mariadb:10.5
    disk: 256

Oracle-mysql uses the oracle-mysql service type:

dbmysql:
    type: oracle-mysql:8.0
    disk: 256

Note that the minimum disk size for mysql/oracle-mysql is 256MB.

Despite these service type differences, MariaDB and Oracle MySQL both use the mysql endpoint in their configuration.

You will need to use mariadb, mysql or oracle-mysql type when defining the service

# .platform/services.yaml
service_name:
      type: mariadb:version
      disk:256

and the endpoint mysql when defining the relationship

# .platform.app.yaml
 relationships:
      relationship_name: “service_name:mysql”

Your service_name and relationship_name are defined by you, but we recommend making them distinct from each other.

You can then use the service in a configuration file of your application with something like:

[!tabs]
Go

{!> web/web-paas/static/files/fetch/examples/golang/mysql !}

Java

{!> web/web-paas/static/files/fetch/examples/java/mysql !}

PHP

{!> web/web-paas/static/files/fetch/examples/php/mysql !}

Python

{!> web/web-paas/static/files/fetch/examples/python/mysql !}

[!primary]
MySQL schema names can not use system reserved namespace. (mysql, information_schema, etc)

Multiple databases

If you are using version 10.0 or later of this service it is possible to define multiple databases as well as multiple users with different permissions. To do so requires defining multiple endpoints. Under the configuration key of your service there are two additional keys:

  • schemas: This is a YAML array listing the databases that should be created. If not specified, a single database named main will be created.
  • endpoints: This is a nested YAML array defining different credentials. Each endpoint may have access to one or more schemas (databases), and may have different levels of permission on each. The valid permission levels are:
    • ro: Using this endpoint only SELECT queries are allowed.
    • rw: Using this endpoint SELECT queries as well INSERT/UPDATE/DELETE queries are allowed.
    • admin: Using this endpoint all queries are allowed, including DDL queries (CREATE TABLE, DROP TABLE, etc.).

Consider the following illustrative example:

db:
    type: mariadb:10.5
    disk: 2048
    configuration:
        schemas:
            - main
            - legacy
        endpoints:
            admin:
                default_schema: main
                privileges:
                    main: admin
                    legacy: admin
            reporter:
                privileges:
                    main: ro
            importer:
                default_schema: legacy
                privileges:
                    legacy: rw

This example creates a single MySQL/MariaDB service named mysqldb. That server will have two databases, main and legacy. There will be three endpoints created. The first, named admin, will have full access to both databases. The second, reporter, will have SELECT query access to the main DB but no access to legacy at all. The importer user will have SELECT/INSERT/UPDATE/DELETE access (but not DDL access) to the legacy database but no access to main.

If a given endpoint has access to multiple databases you should also specify which will be listed by default in the relationships array. If one isn't specified the path property of the relationship will be null. While that may be acceptable for an application that knows the name of the database to connect to, it would mean that automated tools such as the WebPaas CLI will not be able to access the database on that relationship. For that reason the default_schema property is always recommended.

Once those endpoints are defined, you need to expose them to your application as a relationship. Continuing with our example, this would be a possible corresponding block from .platform.app.yaml:

relationships:
    database: "db:admin"
    reports: "db:reporter"
    imports: "db:importer"

This block defines three relationships, database, reports, and imports. They'll be available in the PLATFORM_RELATIONSHIPS environment variable and all have the same structure documented above, but with different credentials. You can use those to connect to the appropriate database with the specified restrictions using whatever the SQL access tools are for your language and application.

If no configuration block is specified at all, it is equivalent to the following default:

configuration:
    schemas:
        - main
    endpoints:
        mysql:
          default_schema: main
          privileges:
            main: admin

If either schemas or endpoints are defined, then no default will be applied and you must specify the full configuration.

Adjusting database configuration

For MariaDB 10.1 and later Oracle MySQL 8.0 and later, a select few configuration properties from the my.cnf file are available for adjustment.

Packet and connection sizing

This value defaults to 16 (in MB). Legal values are from 1 to 100.

db:
    type: mariadb:10.5
    disk: 2048
    configuration:
        properties:
            max_allowed_packet: 64

The above code will increase the maximum allowed packet size (the size of a query or response) to 64 MB. However, increasing the size of the maximum packet will also automatically decrease the max_connections value. The number of connections allowed will depend on the packet size and the memory available to the service. In most cases leaving this value at the default is recommended.

Character encoding

For services created prior to February 2020, the default character set and collation is latin1, which is the default in most MySQL/MariaDB.

For services created after February 2020, the default character set is utf8mb4 and the default collation is utf8mb4_unicode_ci.

Both values can be adjusted at the server level in services.yaml:

db:
  type: mariadb:10.5
  disk: 2048
  configuration:
    properties:
      default_charset: utf8mb4
      default_collation: utf8mb4_unicode_ci

Note that the effect of this setting is to set the character set and collation of any tables created once those properties are set. Tables created prior to when those settings are changed will be unaffected by changes to the services.yaml configuration. However, you can change your own table's character set and collation through ALTER TABLE commands. For example:

# To change defaults when creating new tables:
ALTER DATABASE main CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

# To change defaults when creating new columns:
ALTER TABLE table_name CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

# To convert existing data:
ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

Consult the MySQL documentation for further details.

Storage Engine

We recommend using the InnoDB storage engine wherever possible. MyISAM is only properly supported in Grid environments. In dedicated cluster environments there is no replication of MyISAM tables.

If MyISAM tables are inadvertently created or imported in a dedicated environment they can be converted to use the InnoDB storage engine using the following procedure:

RENAME TABLE <existing> <old>;
INSERT INTO <existing> SELECT * from <old>;

Access your MariaDB service

Assuming your MariaDB relationship is named database, the host name and port number obtained from PLATFORM_RELATIONSHIPS would be database.internal and 3306.

mysql -h database.internal -P 3306 -u user main

If your database relationship has a password, you need to pass the -p switch and enter the password when prompted:

mysql -h database.internal -P 3306 -u user -p main

Outside the application container, you can use WebPaas CLI webpaas sql.

Exporting data

The easiest way to download all data in a MariaDB instance is with the Web PaaS CLI. If you have a single SQL database, the following command will export all data using the mysqldump command to a local file:

webpaas db:dump

If you have multiple SQL databases it will prompt you which one to export. You can also specify one by relationship name explicitly:

webpaas db:dump --relationship database

By default the file will be uncompressed. If you want to compress it, use the --gzip (-z) option:

webpaas db:dump --gzip

You can use the --stdout option to pipe the result to another command. For example, if you want to create a bzip2-compressed file, you can run:

webpaas db:dump --stdout | bzip2 > dump.sql.bz2

Importing data

The easiest way to load data into a database is to pipe an SQL dump through the webpaas sql command, like so:

webpaas sql < my_database_backup.sql

That will run the database backup against the SQL database on Web PaaS. That will work for any SQL file, so the usual caveats about importing an SQL dump apply (e.g., it's best to run against an empty database). As with exporting, you can also specify a specific environment to use and a specific database relationship to use, if there are multiple.

webpaas sql --relationship database -e master < my_database_backup.sql

[!primary]
Importing a database backup is a destructive operation. It will overwrite data already in your database. Taking a backup or a database export before doing so is strongly recommended.