Configuring the database

An overview about how to configure relational databases

This guide explains how to configure the Keycloak server to store data in a relational database.

Supported databases

The server has built-in support for different databases. You can query the available databases by viewing the expected values for the db configuration option. The following table lists the supported databases and their tested versions.

Database Tested Version

mariadb

10

mssql

2016

mysql

8

oracle

12c

postgres

10

By default, the server uses the dev-file database. This is the default database that the server will use to persist data and only exists for development use-cases. The dev-file database is not suitable for production use-cases, and must be replaced before deploying to production.

Configuring a database

For each supported database, the server provides some opinionated defaults to simplify database configuration. You complete the configuration by providing some key settings such as the database host and credentials.

  1. Start the server and set the basic options to configure a database

    bin/kc.[sh|bat] start --db postgres --db-url-host mypostgres --db-username myuser --db-password change_me

    This command includes the minimum settings needed to connect to the database.

The default schema is keycloak, but you can change it by using the db-schema configuration option.

Overriding default connection settings

The server uses JDBC as the underlying technology to communicate with the database. If the default connection settings are insufficient, you can specify a JDBC URL using the db-url configuration option.

The following is a sample command for a PostgreSQL database.

bin/kc.[sh|bat] start --db postgres --db-url jdbc:postgresql://mypostgres/mydatabase

Be aware that you need to escape characters when invoking commands containing special shell characters such as ; using the CLI, so you might want to set it in the configuration file instead.

Configuring Unicode support for the database

Unicode support for all fields depends on whether the database allows VARCHAR and CHAR fields to use the Unicode character set.

  • If these fields can be set, Unicode is likely to work, usually at the expense of field length.

  • If the database only supports Unicode in the NVARCHAR and NCHAR fields, Unicode support for all text fields is unlikely to work because the server schema uses VARCHAR and CHAR fields extensively.

The database schema provides support for Unicode strings only for the following special fields:

  • Realms: display name, HTML display name, localization texts (keys and values)

  • Federation Providers: display name

  • Users: username, given name, last name, attribute names and values

  • Groups: name, attribute names and values

  • Roles: name

  • Descriptions of objects

Otherwise, characters are limited to those contained in database encoding, which is often 8-bit. However, for some database systems, you can enable UTF-8 encoding of Unicode characters and use the full Unicode character set in all text fields. For a given database, this choice might result in a shorter maximum string length than the maximum string length supported by 8-bit encodings.

Configuring Unicode support for an Oracle database

Unicode characters are supported in an Oracle database if the database was created with Unicode support in the VARCHAR and CHAR fields. For example, you configured AL32UTF8 as the database character set. In this case, the JDBC driver requires no special settings.

If the database was not created with Unicode support, you need to configure the JDBC driver to support Unicode characters in the special fields. You configure two properties. Note that you can configure these properties as system properties or as connection properties.

  1. Set oracle.jdbc.defaultNChar to true.

  2. Optionally, set oracle.jdbc.convertNcharLiterals to true.

    For details on these properties and any performance implications, see the Oracle JDBC driver configuration documentation.

Unicode support for a Microsoft SQL Server database

Unicode characters are supported only for the special fields for a Microsoft SQL Server database. The JDBC driver and database require no special settings.

Configuring Unicode support for a MySQL database

Unicode characters are supported in a MySQL database if the database was created with Unicode support in the VARCHAR and CHAR fields when using the CREATE DATABASE command.

Note that the utf8mb4 character set is not supported due to different storage requirements for the utf8 character set. See MySQL documentation for details. In that situation, the length restriction on non-special fields does not apply because columns are created to accommodate the number of characters, not bytes. If the database default character set does not allow Unicode storage, only the special fields allow storing Unicode values.

  1. Start MySQL Server.

  2. Under JDBC driver settings, locate the JDBC connection settings.

  3. Add this connection property: characterEncoding=UTF-8

Configuring Unicode support for a PostgreSQL database

Unicode is supported for a PostgreSQL database when the database character set is UTF8. Unicode characters can be used in any field with no reduction of field length for non-special fields. The JDBC driver requires no special settings. The character set is determined when the PostgreSQL database is created.

  1. Check the default character set for a PostgreSQL cluster by entering the following SQL command.

    show server_encoding;
  2. If the default character set is not UTF 8, create the database with the UTF8 as the default character set using a command such as:

    create database keycloak with encoding 'UTF8';

Changing database locking timeout in a cluster configuration

Because cluster nodes can boot concurrently, they take extra time for database actions. For example, a booting server instance may perform some database migration, importing, or first time initializations. A database lock prevents start actions from conflicting with each other when cluster nodes boot up concurrently.

The maximum timeout for this lock is 900 seconds. If a node waits on this lock for more than the timeout, the boot fails. The need to change the default value is unlikely, but you can change it by entering this command:

bin/kc.[sh|bat] start --spi-dblock-jpa-lock-wait-timeout 900

Using Database Vendors without XA transaction support

Keycloak uses XA transactions and the appropriate database drivers by default. Certain vendors, such as Azure SQL and MariaDB Galera, do not support or rely on the XA transaction mechanism. To use Keycloak without XA transaction support using the appropriate JDBC driver, enter the following command:

bin/kc.[sh|bat] build --db=<vendor> --transaction-xa-enabled=false

Keycloak automatically chooses the appropriate JDBC driver for your vendor.

Setting JPA provider configuration option for migrationStrategy

To setup the JPA migrationStrategy (manual/update/validate) you should setup JPA provider as follows:

Setting the migration-strategy for the quarkus provider of the connections-jpa SPI
bin/kc.[sh|bat] start --spi-connections-jpa-legacy-migration-strategy=manual

If you want to get a SQL file for DB initialization, too, you have to add this additional SPI initializeEmpty (true/false):

Setting the initialize-empty for the quarkus provider of the connections-jpa SPI
bin/kc.[sh|bat] start --spi-connections-jpa-legacy-initialize-empty=false

In the same way the migrationExport to point to a specific file and location:

Setting the migration-export for the quarkus provider of the connections-jpa SPI
bin/kc.[sh|bat] start --spi-connections-jpa-legacy-migration-export=<path>/<file.sql>

Relevant options

Type Default

db

The database vendor.

CLI: --db

Env: KC_DB

dev-file, dev-mem, mariadb, mssql, mysql, oracle, postgres

dev-file

db-password

The password of the database user.

CLI: --db-password

Env: KC_DB_PASSWORD

db-pool-initial-size

The initial size of the connection pool.

CLI: --db-pool-initial-size

Env: KC_DB_POOL_INITIAL_SIZE

db-pool-max-size

The maximum size of the connection pool.

CLI: --db-pool-max-size

Env: KC_DB_POOL_MAX_SIZE

100

db-pool-min-size

The minimal size of the connection pool.

CLI: --db-pool-min-size

Env: KC_DB_POOL_MIN_SIZE

db-schema

The database schema to be used.

CLI: --db-schema

Env: KC_DB_SCHEMA

db-url

The full database JDBC URL.

If not provided, a default URL is set based on the selected database vendor. For instance, if using 'postgres', the default JDBC URL would be 'jdbc:postgresql://localhost/keycloak'.

CLI: --db-url

Env: KC_DB_URL

db-url-database

Sets the database name of the default JDBC URL of the chosen vendor.

If the db-url option is set, this option is ignored.

CLI: --db-url-database

Env: KC_DB_URL_DATABASE

db-url-host

Sets the hostname of the default JDBC URL of the chosen vendor.

If the db-url option is set, this option is ignored.

CLI: --db-url-host

Env: KC_DB_URL_HOST

db-url-port

Sets the port of the default JDBC URL of the chosen vendor.

If the db-url option is set, this option is ignored.

CLI: --db-url-port

Env: KC_DB_URL_PORT

db-url-properties

Sets the properties of the default JDBC URL of the chosen vendor.

If the db-url option is set, this option is ignored.

CLI: --db-url-properties

Env: KC_DB_URL_PROPERTIES

db-username

The username of the database user.

CLI: --db-username

Env: KC_DB_USERNAME

transaction-xa-enabled

If set to false, Keycloak uses a non-XA datasource in case the database does not support XA transactions.

CLI: --transaction-xa-enabled

Env: KC_TRANSACTION_XA_ENABLED

true, false

true

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