How to Manually Adjust Scheduled RDS Application Autoscaling

How to Manually Adjust Scheduled RDS Application Autoscaling

NOTE As of May 2023, the operations detailed here are limited to the test environment and are believed to be strictly optional. Scenarios where an operator elects to make manual adjustments may yield more predictable performance, improved performance, and if nothing else, increased confidence in the results achieved in test regression suite execution. Otherwise, it's deemed harmless to ignore these steps.

Follow this runbook if you need to:

• temporarily suspend scheduled RDS application autoscaling events in test
• scale-out test RDS cluster outside of normal scaled-out hours (M-F 0700-1900 ET)

Scenarios where these operations may be helpful include operations work in test such as:

• out-of-band database maintenance, e.g. upgrades, long-running operations such as database migrations, one-off script execution, etc
• deployments before or after normal scaled-out hours, especially when supporting incident resolution

View All Scheduled Scaling Events

aws application-autoscaling describe-scheduled-actions --service-namespace rds \
  --resource-id cluster:bfd-test-aurora-cluster

NOTE This command reports all scheduled scaling events, regardless of the suspended/unsuspended state of scheduled scaling events.

Suspend/Disable Scheduled Scaling Events

Suspend/Disable with the following command:

aws application-autoscaling register-scalable-target --service-namespace rds \
--scalable-dimension rds:cluster:ReadReplicaCount \
--resource-id cluster:bfd-test-aurora-cluster \
--suspended-state '{"ScheduledScalingSuspended":true}' && \
aws application-autoscaling describe-scalable-targets --service-namespace rds \
    --resource-id cluster:bfd-test-aurora-cluster \
    --query 'ScalableTargets[0].SuspendedState.ScheduledScalingSuspended'

This should return true when disabling scheduled application autoscaling

Unsuspend/Enable Scheduled Scaling Events

Unsuspend/Enable with the following command:

aws application-autoscaling register-scalable-target --service-namespace rds \
--scalable-dimension rds:cluster:ReadReplicaCount \
--resource-id cluster:bfd-test-aurora-cluster \
--suspended-state '{"ScheduledScalingSuspended":false}' && \
aws application-autoscaling describe-scalable-targets --service-namespace rds \
    --resource-id cluster:bfd-test-aurora-cluster \
    --query 'ScalableTargets[0].SuspendedState.ScheduledScalingSuspended'

This should return false when enabling scheduled application autoscaling