CODEWITHSUNDEEP
node.jsamazon-web-servicesaws-lambdaamazon-redshift
DranoMax
DranoMax

Reputation: 504

Connecting to public Redshift DB from Lambda with no VPC

On AWS, I have an API Gateway setup that calls a lambda function which in turns accesses a Redshift database. All of these services are within the same VPC and work. The only problem is that every api call takes a minimum 10 seconds just for spinning up the Lambda function inside a VPC.

From what I've read, if we were to move the Lambda function outside of the VPC it should be able to avoid that 10 second startup. However, is it still possible to connect to the redshift db at that point? The redshift db is publicly accessible but does the lambda function need a VPC in order to access the internet/public redshift db?

Upvotes: 0

Views: 711

Answers (2)

DranoMax
DranoMax

Reputation: 504

So it turns out i was having a timeout issue for the lambda connecting to the redshift db because the zone in the VPC that the redshift db lives in didn't have an IGW route table associated to it. I fixed that and then all I had to do was remove the lambda from its vpc and things just worked.

Long story short: Make sure your redshift db has public internet access.

Upvotes: 0

Red Boy
Red Boy

Reputation: 5719

As others suggested in comments, I would say, look into your Lambda code and see if the dependencies are really complex that it takes so much time in initialization. I far as I understand, its going to take same time irrespective of its inside the VPC or outside.

There is something call as "Cold start / warm call with AWS Lambda", its time when initialization is taking place. As initialization requires building downloading the code, making container up, initializing the container and eventually executing the code.

Its nicely explained here.

https://blog.octo.com/en/cold-start-warm-start-with-aws-lambda/

"The initialization time of a Lambda represents a significant part of the total time. After a cold start, the Lambda will remain instantiated for a while (5 minutes) allowing any other call not to have to wait for this initialization to be done each time."

Regarding your second question, should you put Lambda outside, so the best practice suggests that "don't put Lambda inside the VPC unless you have to".

https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html

Upvotes: 1

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