a9s MariaDB SPI Configuration

This document describes a9s MariaDB SPI configuration.

Custom Parameter Configuration

The a9s MariaDB SPI handles custom parameters for all Service Instances. It does configuration and validation of custom parameters.

The a9s MariaDB SPI defines default values for certain custom parameters. Also, it defines whether a custom parameter can be set by the application developer.

The platform operator can overwrite those choices by changing the a9s MariaDB SPI configuration. The platform operator has to configure the property mariadb-spi.service_instance.custom_param_config. The property value must be a hash. Every key in that hash stands for a custom parameter and the value for every key contains the configuration for that particular parameter. The configuration for a particular parameter is a hash consisting of the following optional keys: default_value and modifiable. The key default_value specifies the default value for that parameter and modifiable specifies whether the application developer is allowed to set that custom parameter. For example:

mariadb-spi:
  service_instance:
    custom_param_config:
      binlog_expire_days:
        default_value: 7
        modifiable: false

Default Custom Parameter Configuration

The following table contains custom parameters that are configurable by the platform operator. The meaning of those custom parameters can be read in the application developer documentation for a9s MariaDB.

Name	Default value	Is modifiable
binlog_expire_days	7	false
databases	null	false

binlog_expire_days

The parameter binlog_expire_days corresponds to the MariaDB configuration parameter expire_log_days.

Example Configuration

Let's build an imaginary example.

The default value for the binlog_expire_days custom parameter should be 5 and the Application Developer should be allowed to change it.

Then the configuration must look the following way:

mariadb-spi:
  service_instance:
    custom_param_config:
      binlog_expire_days:
        default_value: 5
        modifiable: true

danger

The binary log contains a record of all changes to the databases, both data and structure related. Therefore it's necessary for replication and this information should be considered before enabling its modification.

databases

Enabling the databases parameter would mean that the user is able to add and drop databases from the instance, this should be considered before making it modifiable.

mariadb-spi.protocols

For more details on this property, please refer to the a9s Framework TLS configuration documentation.