azure-database-scaler

Event driven Azure Logic App & Functions App that scale-up or scale-down the capacity of your Azure database service instance

Targets Azure Databases to scale in this project:

• Azure Database for MySQL
• Azure Database for PostgreSQL

What to scale up/down?

• vCores (What is vCore?)
• Storage Size (What is Storage size?)

How to scale up/down?

• azure-database-scaler starts changing vCore capacity or Storage size when it was triggered by Azure Monitor Metric Alerts (Alerts providers must be either Microsoft.DBforMySQL or Microsoft.DBforPostgreSQL)
• azure-database-scaler scale-up or scale-down the number of vCore within the same database tier & the same compute generations (Gen4 / Gen5) of your instance in the way like:
  • Basic Tier: 1 <-> 2
  • General Purpose Tier: 2 <-> 4 <-> 8 <-> 16 <-> 32
  • Memory Optimized Tier: 2 <-> 4 <-> 8 <-> 16 <-> 32
• azure-database-scaler only scale-up the Storage size (Not scale-down supported). It can increase the Storage size by the amount of StorageScaleupSize(GB) parameter value to specify in project config file for each scale-up action triggered by Azure Monitor Metric Alerts until the Storage size reaches MaxStorageScaleLimit(GB) parameter value to specify in project config file. MaxStorageScaleLimit(GB) should be within the follwoing storage size range:
  • Basic Tier: 5 GB to 1 TB (1024 GB)
  • General Purpose Tier: 5 GB to 2 TB (2048 GB)
  • Memory Optimized Tier: 5 GB to 2 TB (2048 GB)

Alert Metrics, Alert Operator, and Actions to be triggered

Alert Metric	Metric display name	Operators to match	Action
cpu_percent	CPU percent	GreaterThan or GreaterThanOrEqual	scale-up vCore capacity
cpu_percent	CPU percent	LessThan or LessThanOrEqual	scale-down vCore capacity
storage_percent	Storage percent	GreaterThan or GreaterThanOrEqual	scale-up Storage size
storage_used	Storage used	GreaterThan or GreaterThanOrEqual	scale-up Storage size
storage_limit	Storage limit	GreaterThan or GreaterThanOrEqual	scale-up Storage size

For the detail on the supported metrics, please see supported metrics for Azure Database for MySQL or supported metrics for Azure Database for PostgreSQL

Architecture:

Relevant Services:

• Azure Database for MySQL
• Azure Database for PostgreSQL
• Azure Functions
• Azure Logic Apps
• Azure Monitor Alerts (Classic)
• Slack (for notification)

Documents

• How to deploy the database scaler app
• How to setup Azure Monitor Metric Alerts for Autoscaling(Classic Metric Alert)