What version of gRPC and what language are you using?

1.16.0, python 3.6

What operating system (Linux, Windows, …) and version?

Ubuntu Linux
uname -r returns 4.15.0-38-generic

What runtime / compiler are you using (e.g. python version or version of gcc)

python 3.6

What did you do?

Performing regular unary RPC call with enabled keepalive options and using GRPC_VERBOSITY=Debug and GRPC_TRACE=round_robin to print some Debug logs

What did you expect to see?

No TCP_USER_TIMEOUT not supported for this platform message

What did you see instead?

Even though my kernel version is 4.15 I see the following message in the log:

I1113 14:16:31.657144159 22799 socket_utils_common_posix.cc:310] TCP_USER_TIMEOUT not supported for this platform

According to this code

in order to use TCP_USER_TIMEOUT option my kernel version needs to be higher than 2.6.37

See https://github.com/grpc/grpc/blob/master/TROUBLESHOOTING.md for how to diagnose problems better.

Anything else we should know about your project / environment?