Amazon ECS · Rate Limits

Amazon Ecs Rate Limits

Amazon ECS API requests are throttled per-account, per-Region using AWS's standard token-bucket model. Throttle limits are not publicly published per action and can be increased via Service Quotas or AWS Support. ThrottlingException / RequestLimitExceeded responses signal throttling. AWS recommends exponential backoff with jitter (truncated binary, max 20s) and the standard SDK retry mode.

2 Limits Throttle: 400
Rate LimitingAmazonContainersECS

Limits

Per-account ECS API throttling account/region
varies
see Service Quotas console for ECS
Limits vary per API action (e.g. RunTask, DescribeServices) and per Region. Defaults are not publicly listed; use the Service Quotas console or open a support case to view or raise.
ECS Anywhere registration account/region
varies
see Service Quotas console for ECS
Same throttling envelope; subject to ECS Anywhere quota for external instance registrations per cluster.

Policies

Standard retry mode
AWS SDKs default to standard retry mode with truncated binary exponential backoff and jitter (b * 2^i, capped at 20s) and a max of 3 attempts unless overridden.
Adaptive retry mode
Optional client-side rate limiting via token bucket; recommended only when clients are pooled per throttle scope (region + resource).
Quota increases
Most ECS quotas (cluster count, services per cluster, tasks per service, API TPS) can be raised via the Service Quotas console or AWS Support.
ThrottlingException response
AWS returns HTTP 400 with error code ThrottlingException or RequestLimitExceeded; legacy services may return 503. Honor Retry-After when present.

Sources