Quotas

Service quota names and defaults also appear under Amazon EC2 endpoints and quotas in the AWS General Reference. Request increases in the Service Quotas console.

Feature quotas

A target is one instance monitored by one health check. If two checks monitor the same instance, that is two targets.

An association is one tag rule or one instance ID attached to a check, regardless of how many instances the tag currently matches.

Quota	Default	Increase
Health checks per account	50	Automatic
Associations per health check	50	Automatic
Associations per account	200	Automatic
Targets per account	5,000	Request (manual approval)

Most increases auto-approve. Targets per account requires a ticket.

Danger

If target count exceeds the account quota, targets over the limit are not monitored and do not report application status. There is no noisy failure for the overflow set. Alarm AWS/Usage for this quota before you associate a broad production tag.

Related VPC quota

Managed ENIs count against ENIs per VPC. If that quota is exhausted, AWS cannot create the health-check ENI and the check cannot run.

Suggested alarms

• Service Quotas usage metrics in AWS/Usage for health checks, associations, and targets.
• StatusCheckFailed_Application on a canary instance after you flip aggregation to included.