I have a function that update my dictionary each time a new file is send to aws s3. The aws lambda has an edit concurrency like this.
according to this discussion you can set concurrency to 1, but in my case it isn't.
The reason is to prevent data racing in reading and writing my dictionary.
It seems there is a restriction with unreserved account concurrency in your AWS account. You should raise a support case for increasing that limit. Once you increase, you can reserve the concurrency limit for your function.
From documentation,
You can reserve up to the Unreserved account concurrency value that is shown, minus 100 for functions that don't have reserved concurrency. To throttle a function, set the reserved concurrency to zero. This stops any events from being processed until you remove the limit.
In your case, unreserved account concurrency is 10 (normally it is 1000) and the minimum shared concurrency for functions that don't have reserved concurrency is also 10(normally this is 100). So when you try to reserve concurrency for a function, the shared concurrency will go down the minimum threshold and that makes the error.
Increasing your unreserved account concurrency will solve your issue. You can refer to the following link. https://aws.amazon.com/premiumsupport/knowledge-center/lambda-concurrency-limit-increase/
