Aurora (RDS)

This page contains information about using the Aurora service in Handel. This service provides an Aurora cluster (MySQL or PostgreSQL) via the RDS service.

Service Limitations

No Option Group Support

This service doesn’t allow you to specify any custom options in an option group. It does allow you specify custom parameters in a parameter group, however.

No Update Support

This service intentionally does not support updates. Once a database is created, certain updates to the database will cause a new database to be created and the old one deleted. In an effort to avoid unwanted data loss, we don’t update this service automatically. You can still modify the database and parameter group manually in the AWS console.

Warning

Make sure you know what you’re doing when you modify your RDS database in the AWS Console. Certain actions will cause database downtime, and some may even cause the database to be recreated.

Parameters

Parameter	Type	Required	Default	Description
type	string	Yes		This must always be aurora for this service type.
engine	string	Yes		The Aurora engine you wish to use. Allowed values: ‘mysql’, ‘postgresql’
version	string	Yes		The version of MySQL or PostgreSQL you wish to run. Allowed values for MySQL: ‘5.7.12’. Allowed values for PostgreSQL: ‘9.6.3’.
database_name	string	Yes		The name of your database in your Aurora cluster.
description	string	No		The description on the resources created for the cluster
instance_type	string	No	db.t2.small for MySQL, db.r4.large for PostgreSQL.	The size of database instance to run. Not all database instance types are supported for Aurora.
cluster_size	number	No	1	The number of instances (including the primary) to run in your cluster.
cluster_parameters	map<string, string>	No		A list of key/value Aurora cluster parameter group pairs to configure your cluster. You will need to look in the AWS Console to see the list of available cluster parameters for Aurora.
instance_parameters	map<string, string>	No		A list of key/value Aurora instance parameter group pairs to configure the instances in your cluster. You will need to look in the AWS Console to see the list of available instance parameters for Aurora.
tags	Resource Tags	No		Any tags you wish to apply to this Aurora instance.

Warning

Be aware that Aurora clusters can be very expensive. A cluster with 3 db.r4.2xlarge instances in it will cost about about $2,500/month. Make sure you check how much you will be paying!

You can use the excellent EC2Instances.info site to easily see pricing information for RDS databases. Remember that you pay the full price for each instance in your cluster.

Example Handel File

version: 1

name: aurora-test

environments:
  dev:
    database:
        type: aurora
        engine: mysql
        version: 5.7.12
        database_name: MyDb
        instance_type: db.t2.medium
        cluster_size: 3
        cluster_parameters: # This is where you can set parameters that configure the cluster as a whole
            character_set_database: utf8mb4
        instance_parameters: # This is where you can set parameters that apply to each instance.
            autocommit: 1
        tags:
            some: tag

Depending on this service

The Aurora service outputs the following environment variables:

Environment Variable	Description
<SERVICE_NAME>_CLUSTER_ENDPOINT	The address that you should use for writes to the database.
<SERVICE_NAME>_READ_ENDPOINT	The address that you should use for reads to the database.
<SERVICE_NAME>_PORT	The port on which the Aurora cluster instances are listening.
<SERVICE_NAME>_DATABASE_NAME	The name of the database in your Aurora cluster.

See Environment Variable Names for information about how the service name is included in the environment variable name.

In addition, the Aurora service puts the following credentials into the EC2 parameter store:

Parameter Name	Description
<parameter_prefix>.<service_name>.db_username	The username for your database user.
<parameter_prefix>.<service_name>.db_password	The password for your database user.

Note

The <parameter_prefix> section of the parameter name is a consistent prefix applied to all parameters injected by services in the EC2 Parameter Store. See Parameter Store Prefix for information about the structure of this prefix.

The <service_name> section of the parameter name should be replaced by the service name you gave your database in your Handel file.

Events produced by this service

The Aurora service does not produce events for other Handel services to consume.

Events consumed by this service

The Aurora service does not consume events from other Handel services.