Restarting AWS lambda function to clear cache

Question

I have a AWS Lambda function that creates an object from a s3 call in cold start. I then hold the object in the cache while the function is warm to keep load times down. When files are changed in s3, I have a trigger to run the lambda, but not all the running instances of lambda restart and pull from s3.

Is there a way to bring down all instances of lambda forcing a full cold start?

Also, I don't want to use python.

Answer 1

I made an Answer based on my comment and verification from @DejanVasic

aws lambda update-function-configuration --function-name "myLambda" --description "foo" 

This will force the next invokation of the lambda to "cold start".

To verify:

@timestamp, @message | sort @timestamp desc | limit 1000 | filter @message like "cold_start:true" 

Answer 2

Use the UpdateFunctionCode API endpoint to force a refresh of all containers. AWS SDKs wrap this up to make it easier for you to call the API using your preferred language.