Request quotas
AWS KMS establishes quotas for the number of API operations requested in each second. The request quotas differ with the API operation, the AWS Region, and other factors, such as the KMS key type. When you exceed an API request quota, AWS KMS throttles the request.
If you need to exceed a quota, you can request a quota increase in Service Quotas. Use the
Service Quotas console
For help requesting an increase in an AWS KMS quota, see Requesting an AWS KMS quota increase.
If you are exceeding the request quota for the GenerateDataKey operation, consider using the data key caching feature of the AWS Encryption SDK. Reusing data keys might reduce the frequency of your requests to AWS KMS.
In addition to request quotas, AWS KMS uses resource quotas to ensure capacity for all users. For details, see Resource quotas.
To view trends in your request rates, use the Service Quotas console
Topics
Request quotas for each AWS KMS API operation
This table lists the Service Quotas quota code and the default value for each AWS KMS request quota.
You might need to scroll horizontally or vertically to see all of the data in this table.
Quota name | Default value (per second) |
---|---|
Applies to:
|
These shared quotas vary with the AWS Region and the type of KMS key used in the request. Each quota is calculated separately.
Custom key stores quota (symmetric KMS keys):
|
Applies to:
|
500 (shared) for RSA KMS keys |
Applies to:
|
300 (shared) for elliptic curve (ECC) KMS keys |
|
5 |
|
5 |
|
5 |
|
5 |
|
50 |
|
5 |
|
15 |
|
5 |
|
5 |
|
5 |
|
2000 |
|
5 |
|
5 |
|
5 |
|
5 |
|
15 |
Applies to:
|
25 |
Applies to:
|
10 |
Applies to:
|
5 |
Applies to:
|
25 |
Applies to:
|
1 |
Applies to:
|
0.5 (1 in each 2-second interval) |
Applies to:
|
0.1 (1 in each 10-second interval) |
|
1000 |
|
1000 |
|
0.25 (1 in each 4-second interval) |
|
2000 |
|
5 |
|
500 |
|
100 |
|
100 |
|
500 |
|
2000 |
|
100 |
|
15 |
ReplicateKey request rate
A |
5 |
|
30 |
|
30 |
|
15 |
|
10 |
|
5 |
|
5 |
|
5 |
|
5 |
An |
5 |
Applying request quotas
When reviewing request quotas, keep in mind the following information.
-
Request quotas apply to both customer managed keys and AWS managed keys. The use of AWS owned keys does not count against request quotas for your AWS account, even when they are used to protect resources in your account.
-
Request quotas apply to requests sent to FIPS endpoints and non-FIPS endpoints. For a list of AWS KMS service endpoints, see AWS Key Management Service endpoints and quotas in the AWS General Reference.
-
Throttling is based on all requests on KMS keys of all types in the Region. This total includes requests from all principals in the AWS account, including requests from AWS services on your behalf.
-
Each request quota is calculated independently. For example, requests for the CreateKey operation have no effect on the request quota for the CreateAlias operation. If your
CreateAlias
requests are throttled, yourCreateKey
requests can still complete successfully. -
Although cryptographic operations share a quota, the shared quota is calculated independently of quotas for other operations. For example, calls to the Encrypt and Decrypt operations share a request quota, but that quota is independent of the quota for management operations, such as EnableKey. For example, in the Europe (London) Region, you can perform 10,000 cryptographic operations on symmetric KMS keys plus 5
EnableKey
operations per second without being throttled.
Shared quotas for cryptographic operations
AWS KMS cryptographic operations share request quotas. You can request any combination of the cryptographic operations that are supported by the KMS key, just so the total number of cryptographic operations doesn't exceed the request quota for that type of KMS key. The exceptions are GenerateDataKeyPair and GenerateDataKeyPairWithoutPlaintext, which share a separate quota.
The quotas for different types of KMS keys are calculated independently. Each quota applies to all requests for these operations in the AWS account and Region with the given key type in each one-second interval.
-
Cryptographic operations (symmetric) request rate is the shared request quota for cryptographic operations using symmetric KMS keys in an account and region. This quota applies to cryptographic operations with symmetric encryption keys and HMAC keys, which are also symmetric.
For example, you might be using symmetric KMS keys in an AWS Region with a shared quota of 10,000 requests per second. When you make 7,000 GenerateDataKey requests per second and 2,000 Decrypt requests per second, AWS KMS doesn't throttle your requests. However, when you make 9,500
GenerateDataKey
requests and 1,000 Encrypt and requests per second, AWS KMS throttles your requests because they exceed the shared quota. -
Cryptographic operations (RSA) request rate is the shared request quota for cryptographic operations using RSA asymmetric KMS keys.
For example, with a request quota of 500 operations per second, you can make 200 Encrypt requests and 100 Decrypt requests with RSA KMS keys that can encrypt and decrypt, plus 50 Sign requests and 150 Verify requests with RSA KMS keys that can sign and verify.
-
Cryptographic operations (ECC) request rate is the shared request quota for cryptographic operations using elliptic curve (ECC) asymmetric KMS keys.
For example, with a request quota of 300 operations per second, you can make 100 Sign requests and 200 Verify requests with RSA KMS keys that can sign and verify.
The quotas for different key types are also calculated independently. For example, in the Asia Pacific (Singapore) Region, if you use both symmetric and asymmetric KMS keys, you can make up to 10,000 calls per second with symmetric KMS keys (including HMAC keys) plus up to 500 additional calls per second with your RSA asymmetric KMS keys, plus up to 300 additional requests per second with your ECC-based KMS keys.
API requests made on your behalf
You can make API requests directly or by using an integrated AWS service that makes API requests to AWS KMS on your behalf. The quota applies to both kinds of requests.
For example, you might store data in Amazon S3 using server-side encryption with a KMS key
(SSE-KMS). Each time you upload or download an S3 object that's encrypted with SSE-KMS, Amazon S3
makes a GenerateDataKey
(for uploads) or Decrypt
(for downloads)
request to AWS KMS on your behalf. These requests count toward your quota, so AWS KMS throttles
the requests if you exceed a combined total of 5,500 (or 10,000 or 50,000 depending upon your
AWS Region) uploads or downloads per second of S3 objects encrypted with SSE-KMS.
Cross-account requests
When an application in one AWS account uses a KMS key owned by a different account, it's known as a cross-account request. For cross-account requests, AWS KMS throttles the account that makes the requests, not the account that owns the KMS key. For example, if an application in account A uses a KMS key in account B, the KMS key use applies only to the quotas in account A.
Custom key store quota
AWS KMS custom key stores support only symmetric encryption KMS keys. The cryptographic operations that use
the KMS keys in a custom key store share a
request quota of 1,800 operations per second for each custom key store. However, not all
operations use the quota equally. The GenerateDataKey
,
GenerateDataKeyWithoutPlaintext
, and GenerateRandom
operations use
approximately three times as much of the per-second quota as the Encrypt
,
Decrypt
, and ReEncrypt
operations.
For example, if you are requesting only Encrypt
and Decrypt
operations, you can perform approximately 1,800 operations per second. If, instead, you
request repeated GenerateDataKey
operations, your performance might be closer to
600 operations per second. For applications patterns that consist of roughly equal numbers of
GenerateDataKey
and Decrypt
operations, you can expect about 1,200
operations per second.
Unlike other AWS KMS quotas, the custom key store quota is not adjustable. You cannot increase it by using Service Quotas or by creating a case in AWS Support.
If the AWS CloudHSM cluster that is associated with the custom key store is processing numerous
commands, including those unrelated to the custom key store, you might get an AWS KMS
ThrottlingException
at a lower-than-expected rate. If this occurs, lower your
request rate to AWS KMS, reduce the unrelated load, or use a dedicated AWS CloudHSM cluster for your
custom key store.