Request Syntax URI Request Parameters Request Body Response Syntax Response Elements Errors See Also

PutFunctionConcurrency

Sets the maximum number of simultaneous executions for a function, and reserves capacity for that concurrency level.

Concurrency settings apply to the function as a whole, including all published versions and the unpublished version. Reserving concurrency both ensures that your function has capacity to process the specified number of events simultaneously, and prevents it from scaling beyond that level. Use GetFunction to see the current setting for a function.

Use GetAccountSettings to see your Regional concurrency limit. You can reserve concurrency for as many functions as you like, as long as you leave at least 100 simultaneous executions unreserved for functions that aren't configured with a per-function limit. For more information, see Lambda function scaling.

Request Syntax


PUT /2017-10-31/functions/FunctionName/concurrency HTTP/1.1
Content-type: application/json

{
   "ReservedConcurrentExecutions": number
}

URI Request Parameters

The request uses the following URI parameters.

FunctionName

The name or ARN of the Lambda function.

Name formats

Function name – my-function.
Function ARN – arn:aws:lambda:us-west-2:123456789012:function:my-function.
Partial ARN – 123456789012:function:my-function.

The length constraint applies only to the full ARN. If you specify only the function name, it is limited to 64 characters in length.

Length Constraints: Minimum length of 1. Maximum length of 140.

Pattern: (arn:(aws[a-zA-Z-]*)?:lambda:)?([a-z]{2}(-gov)?-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?

Required: Yes

Request Body

The request accepts the following data in JSON format.

ReservedConcurrentExecutions

The number of simultaneous executions to reserve for the function.

Type: Integer

Valid Range: Minimum value of 0.

Required: Yes

Response Syntax


HTTP/1.1 200
Content-type: application/json

{
   "ReservedConcurrentExecutions": number
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

ReservedConcurrentExecutions

The number of concurrent executions that are reserved for this function. For more information, see Managing Lambda reserved concurrency.

Type: Integer

Valid Range: Minimum value of 0.

Errors

For information about the errors that are common to all actions, see Common Errors.

InvalidParameterValueException

One of the parameters in the request is not valid.

HTTP Status Code: 400

ResourceConflictException

The resource already exists, or another operation is in progress.

HTTP Status Code: 409

ResourceNotFoundException

The resource specified in the request does not exist.

HTTP Status Code: 404

ServiceException

The AWS Lambda service encountered an internal error.

HTTP Status Code: 500

TooManyRequestsException

The request throughput limit was exceeded. For more information, see Lambda quotas.

HTTP Status Code: 429