In many places, we use a deadline to calculate a timeout. If the deadline has already passed when we submit the RPC, we get an error like:
I1124 13:21:39.261135 15815 runtime-state.cc:228] Error from query d24cf508e3437ab5:1ac8794be69d81a9: Unable to open scanner: Timed out: Scan RPC to 10.17.223.30:7050 timed out after -0.181s
which doesn't make a lot of sense. We should improve the error in this case to be more understandable.