Lambda Warmer: Optimize AWS Lambda Function Cold Starts

At a recent AWS Startup Day event in Boston, MA, Chris Munns, the Senior Developer Advocate for Serverless at AWS, discussed Lambda cold starts and how to mitigate them. According to Chris (although he acknowledge that it is a “hack”) using the CloudWatch Events “ping” method is really the only way to do it right now. He gave a number of really good tips to pre-warm your functions “correctly”:

  • Don’t ping more often than every 5 minutes
  • Invoke the function directly (i.e. don’t use API Gateway to invoke it)
  • Pass in a test payload that can be identified as such
  • Create handler logic that replies accordingly without running the whole function

Continue Reading…