I've built some microservices using kubernetes and the pods communicate using gRPC. I've set keepalive settings on both client and server (copy and pasted the settings from here: https://cs.mcgill.ca/~mxia3/2019/02/23/Using-gRPC-in-Production/ ), however after a period of inactivity the first gRPC request will still fail, returning an UNAVAILABLE error.

I'm using Alibaba's ACK to host my app, and built my app in python.

Anyone have any ideas on how to troubleshoot? I'm at a loss.