I am trying to run f8test. It fails to re-connect on connection errors, the log:
It basically says, that after connect() timed out, further connection attempts failed with EINPROGESS, whereas they should fail with the same error.
Looking in the source code ClientConnection::connect() it seems that the socket is not re-created before trying to connect again.
Also, the socket options should be set before connecting, otherwise they may have no effect, see man tcp(7):
On individual connections, the socket buffer size must be set prior to the listen(2) or connect(2) calls in order to have it take effect. See socket(7) for more information.