Workaround · Performance · Blocks work
Per-flow ECS task launch adds minutes of startup delay
1 source thread · first seen 2025-11
Summary
Each Prefect flow starts in its own ECS task, so slow container startup on Fargate added up. The team moved to an EC2 autoscaling group with a custom AMI that has images pre-baked, cutting startup from about 3 minutes to 30 seconds.
- Affects
- teams running flows on AWS ECS
- Workaround
- Switched from Fargate to an EC2 auto scaling group with a custom AMI containing pre-baked container images
Evidence
Excerpts are copied word for word from the source; follow the link to read it in full.
“each prefect flow launches in a discrete ECS task so the waiting added up”