@calmoo I'm having some issues with lambda performance even with docker-reuse (~12 seconds cold start, ~8 seconds once warm). What sort of response times do you see with docker-reuse?

@jleck After first invocation, I got the response time down from ~10-12 seconds to under 1 second.

Might be something my end that's slowing it down still then after the first. Thanks!

@calmoo What's your setup to achieve <1s ?

See my issue with my setup: #4042

I'm doing some extensive testing on our services using localstack, and the slowness is kinda annoying. Can someone explain why a lambda should even take 1s (which is what I'm seeing) with docker-reuse. In AWS we get milliseconds. Isn't it just a method call to the handler function? Is the container reinitialized for each invoke?

Thanks for reporting @tobias-zeptio @ThomasLabstep @jleck @noahskelton . We have recently introduced "stay-open" mode which further improves the Lambda execution times, and is now the default for the docker-reuse Lambda executor (see PR #4914). Can you confirm that the execution times have improved in recent versions, or are you still experiencing these performance issues?

From a compatibility perspective we're currently still leaning towards having docker as the default executor, as this is the "zero-assumption" mode that works out of the box (without opening any separate network ports, allowing multiple invocations in parallel, etc). We'll make sure to add a note to the troubleshooting section of our documentation (our README/docs are currently being refactored, but we'll take it into account 👍 /cc @HarshCasper ). Thanks!