Amazon S3 on Outposts now caches AWS IAM permissions locally, improving the performance of applications running on AWS Outposts. This local cache eliminates the variability in first-byte latencies that comes from authentication and authorization operations in the parent AWS Region, which improves the performance of your object API requests.

After you make an API request to S3 on Outposts, AWS IAM permissions for S3 on Outposts are securely cached locally on the Outpost. Your subsequent S3 object API requests will be authenticated and authorized using cached data, eliminating the latency incurred from a round trip to the AWS Region. The cache will be valid for up to 10 minutes when the Outpost is connected to the AWS Region, and will be refreshed asynchronously when you make an S3 on Outposts API request, so that the latest permissions are used. To take advantage of the local cache, you need to sign API requests with the SigV4A algorithm, which is available in the latest versions of the AWS SDKs, and is obtained through a dependency on the AWS Common Runtime (CRT) libraries.

Support for S3 on Outposts authentication and authorization cache is available in all AWS Regions where S3 on Outposts is available at no additional cost. To get started or learn more, visitENnbsp;the S3 on Outposts page or read our documentation.