Posted On: Jul 17, 2023

Customers running applications on Amazon Elastic Container Service (ECS) with AWS Fargate can now leverage Seekable OCI (SOCI), a technology open sourced by AWS that helps applications deploy and scale out faster by enabling the containers to start without waiting for the entire container image to be downloaded. 

Most methods for launching containers download the entire container image from a remote container registry before starting the container. Waiting for the entire image to download is unnecessary as in many cases only a small portion of it is needed for startup. SOCI reduces this wait time by lazily loading the image data in parallel to application startup, enabling containers to start with only a fraction of the image.

To use SOCI, you simply need to build an index (SOCI Index) of the container image files. Since this index is generated separately from the image and stored as a separate artifact in the registry, the image and its digest do not change. Furthermore, you don’t have to change the task definitions. When starting an Amazon ECS task, AWS Fargate automatically detects if a SOCI index for a container image exists and starts it without waiting for the entire image to download. This enables applications to scale out quickly and reduces the roll out time for application updates.

You can start using SOCI for applications running on Amazon ECS with AWS Fargate at no additional cost. You will just be charged for storing the SOCI index in Amazon ECR. To get started, visit the documentation and the blog post. This feature is available in all regions where Amazon ECS, AWS Fargate, and Amazon ECR are available.