query=http_requests_total
query=http_requests_total&start=2018-01-20T00:00:00.000Z&end=2018-01-25T00:00:00.000Z&step=60s
example: until now range query
query=http_requests_total&start=2018-01-20T00:00:00.000Z&step=60s
query=http_requests_total&start=2018-01-20T00:00:00.000Z&end=now&step=60s
# end is assumed now, start is end-duration
query=http_requests_total&duration=1h5m10s20ms&step=60s
# end is (start + duration)
query=http_requests_total&start=2018-01-20T00:00:00.000Z&duration=1h&step=60s
# start is (end - duration), end is now
query=http_requests_total&duration=1h&step=60s
#start is (end - duration), end is now
query=http_requests_total&end=2018-01-20T00:00:00.000Z&duration=1h&step=60s