Configuring a distributed EOP Installation using an Azure MySQL database instance

Objective

Use an Azure MySQL database instance to host the Contrast database for a distributed EOP Installation.

Process

As documented in Step 6. here, the usual configuration for the Contrast database user is to grant all privileges using:

 GRANT ALL PRIVILEGES ON *.* TO 'contrast'@'%';

With an Azure MySQL instance, even the admin user that is provided for managing your instance does not possess all privileges, so it will be impossible to configure the contrast user as suggested.

Instead, the maximum permission level you can set for the contrast user is as follows:

GRANT 
SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, PROCESS, REFERENCES,
INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE,
REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE,
ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE ROLE, DROP ROLE 
ON *.* TO `contrast`@`%` WITH GRANT OPTION;

In addition to configuring the user as such, the following steps need also be taken to avoid potential issues:

Modify Azure MySQL Database Server Parameters

In the Azure Management Console, edit the Server Parameters for the database as follows:

• Set max_allowed_packets to 1073741824 (this allows the database to handle larger packets and strings).
• Set the log_bin_trust_function_creators parameter to ON.
• Set the explicit_defaults_for_timestamp parameter to OFF.
• Set the wait_timeout parameter to 360 (to avoid this issue).

Modify Database Connection Properties

The Azure MySQL Database instances return the incorrect MySQL version when the default port (3306) is used to connect, as detailed in this article.  As the Contrast Server requires a minimum MySQL version of 5.7, this will result in an error.  The workaround for this is to either:

• Use port 3308 (if your Azure MySQL instance is 5.7) or 3309 (if your Azure MySQL instance is 8.0) (recommended)
• or add the JVM option -Dmysql.min.version=5.6.42 to the <CONTRAST_INSTALL_DIR>/bin/contrast-server.vmoptions file.

To modify the port, edit both jdbc.url and jdbc.port the in the <CONTRAST_INSTALL_DIR>/data/conf/database.propertiesfile (details on how to edit this file are here).

If the Azure MySQL database instance requires TLS connections, please refer to the additional instructions in this article to complete the configuration.