Comment 3 for bug 1855912

Hello:

I tested manually with 10.4 on Ubuntu 18.04.

$ apt-get remove mariadb-server
$ apt purge mariadb-common
$ apt-get install software-properties-common
$ apt update ; apt upgrade -y; apt clean ; apt autoremove -y
$ apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
$ add-apt-repository "deb [arch=amd64,arm64,ppc64el] http://mariadb.mirror.liquidtelecom.com/repo/10.4/ubuntu $(lsb_release -cs) main"

Then I executed devstack, in master branch, and the installation finished without any problem.

From the MariaDB 10.4 backend:

DDL for neutron.ovn_revision_numbers:
CREATE TABLE `ovn_revision_numbers` (
  `standard_attr_id` bigint(20) DEFAULT NULL,
  `resource_uuid` varchar(36) NOT NULL,
  `resource_type` varchar(36) NOT NULL,
  `revision_number` bigint(20) NOT NULL DEFAULT 0,
  `created_at` datetime NOT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`resource_uuid`,`resource_type`),
  KEY `standard_attr_id` (`standard_attr_id`),
  KEY `ix_ovn_revision_numbers_resource_type` (`resource_type`),
  KEY `ix_ovn_revision_numbers_resource_uuid` (`resource_uuid`),
  CONSTRAINT `ovn_revision_numbers_ibfk_1` FOREIGN KEY (`standard_attr_id`) REFERENCES `standardattributes` (`id`) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8

DDL for neutron.ovn_hash_ring:
CREATE TABLE `ovn_hash_ring` (
  `node_uuid` varchar(36) NOT NULL,
  `group_name` varchar(256) NOT NULL,
  `hostname` varchar(256) NOT NULL,
  `created_at` datetime NOT NULL,
  `updated_at` datetime NOT NULL,
  PRIMARY KEY (`node_uuid`,`group_name`),
  KEY `ix_ovn_hash_ring_node_uuid` (`node_uuid`),
  KEY `ix_ovn_hash_ring_group_name` (`group_name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

In OpenStack, we can:
- Wait for a Ubuntu Bionic upgrade of the MariaDB version distribution.
- Add this new repository and install v10.4.

Regards.