To configure a reserved concurrency limit for a function

The following put-function-concurrency example configures 100 reserved concurrent executions for the my-function function.

aws lambda put-function-concurrency \
    --function-name  my-function  \
    --reserved-concurrent-executions 100

Output:

{
    "ReservedConcurrentExecutions": 100
}

For more information, see Reserving Concurrency for a Lambda Function in the AWS Lambda Developer Guide.