[keycloak-dev] Better supported methods for active/active relational db clusters?

[Alec Lazarescu]

I was hoping to start a conversation on what's the best path forward to get
maintainable support for active/active db's that have schema restrictions
that are not upheld historically by Keycloak's schema and Liquibase based
setup.


How best can we make often minor schema adjustments in a maintainable
fashion going forward? Perhaps a method to choose on install/upgrade
between fully backwards compatible migrations vs the migration style that
supports active/active?


The Keycloak docs mention Oracle RAC and MySQL Galera for example
https://www.keycloak.org/docs/latest/server_installation/index.html#database
and I saw a PR for Postgres-BDR that was rejected due to understandable
migration concerns for existing installs:


https://issues.jboss.org/browse/KEYCLOAK-5769


For Reference:


MariaDB Galera limitations
<https://mariadb.com/kb/en/library/mariadb-galera-cluster-known-limitations/>

Postres-BDR limitations
<http://bdr-project.org/docs/1.0.3/ddl-replication-statements.html>


Thanks!

Alec