InfluxDB returns nothing on group by time queries when there is no data in the database regardless of FILL

[nhaugo]

Bug report

InfluxDB: 1.3.7
OS: MacOSX, Ubuntu 16.04

Perform a query like:
select mean(usage_user) from cpu where time < now() - 1000000m AND time > now() - 1000000m - 1m group by time(10s) fill(0)

Where there is no data in the requested time frame

Expected behavior: I would expect the database to return timestamps with the fill value

Actual behavior: Nothing is returned

[rbetts]

@jsternberg I have a vague memory that you explained to me that this was by design? Perhaps the DB doesn't fill until it finds the first non-empty group; otherwise you'd have to express a lower time bound on all queries or fill from epoch time 0 forward?

[rbetts]

From docs:

Currently, queries ignore fill() if no data fall within the query’s time range. This is the expected behavior. An open feature request on GitHub proposes that fill() should force a return of values even if the query’s time range covers no data.

See also: #6878 and #6967