title: Can I limit concurrent invocations of an AWS Lambda?
body: <p>I have a Lambda function that’s triggered by a PUT to an S3 bucket.</p>
  
  <p>I want to limit this Lambda function so that it’s only running one instance at a time – I don’t want two instances running concurrently.</p>
  
  <p>I’ve had a look through the Lambda configuration and docs, but I can’t see anything obvious. I can about writing my own locking system, but it would be nice if this was already a solved problem.</p>
  
  <p><strong>How can I limit the number of concurrent invocations of a Lambda?</strong></p>