These 125ms are only the startup time of the MVM and don't include additional latency introduced by optimizing the code package and the involvement of the placement service.
You can also avoid the cold start penalties entirely, if you're willing to pay extra for provisioned concurrency [1].
[1]: https://docs.aws.amazon.com/lambda/latest/dg/configuration-c...
Re:Behind the scenes, AWS Lambda
by bigodanktime on Sunday July 11, 2021 @01:31PM
(#27802852)
This seems to be a solution that comes at the cost of the consumer which is fine if they want to pay for it, and seems to be an option provided for more latency sensitive applications.
Obviously, one could eliminate the cold start issue in general by just constantly paying for a running EC2 instance.
But cold start is still an issue for the provider as cold start is a cost to them, even reducing cold start of internal runtimes would be a massive benefit (For example pre-warmed JITs). Better cold start times means better bin packing for their services, and overall less cost to everyone.
https://arxiv.org/pdf/2101.09355.pdf
Also predicting function calls to properly schedule and reduce cold start latency
https://www.usenix.org/system/files/atc20-shahrad.pdf