Why did I receive a ThrottlingExceptions error with API requests that are made to AWS KMS?

Short description

The ThrottlingException error code indicates that the rate of API requests to AWS KMS exceeds the request quotas for your AWS account. As a result, the AWS KMS service throttles the API request.

Resolution

Use the following best practices to troubleshoot ThrottlingException errors:

• Review AWS KMS usage metrics from the service quotas to identify the maximum and average rate of API requests per second. AWS KMS publishes usage metrics to Amazon CloudWatch for different AWS KMS API request quotas. For example, Encrypt and Decrypt operations use shared quotas for cryptographic operations.
• Reduce the rate of API requests and usage, or modify the backoff and retry logic.
• For server-side encryption with AWS KMS keys (SSE-KMS) for Amazon Simple Storage Service (Amazon S3) buckets, use an S3 bucket key. For instructions, see Reduce the cost of SSE-KMS with Amazon S3 bucket keys.
• Use the data key caching feature with the AWS Encryption SDK encryption library.
• Request an AWS KMS quota increase that exceeds the API request quota.
• Create a CloudWatch alarm to alert you when a utilization percentage is reached before you reach the request quota.

Related information

What happens to new or existing objects when I turn on default encryption with AWS KMS on my Amazon S3 bucket?