Continuous query has run time but writes zero points

I have an interesting problem.

I have successfully been writing a reasonable volume of counter value data to InfluxDB for about six months. I was running version 1.3.1 till yesterday. Part of my configuration was running a continuous query that took the counter value data (it’s router interface counters, so bytes are the unti), got the 1 second derivative value and then multiplied it by 8 to get the bitrate value, then stored it in another measurement in the same database. This query had been working fine.

I updated to 1.4.2 yesterday, after I’d been running it on a test device for a few weeks with no issue. My generated rate measurement has not updated since, and I get log entries like this:

Feb 7 14:10:16 influx-m1 influxd: [I] 2018-02-07T19:10:16Z finished continuous query traffic_rate, 0 points(s) written (2018-02-07 19:05:00 +0000 UTC to 2018-02-07 19:10:00 +0000 UTC) in 16.270452777s service=continuous_querier

I have tried dropping and adding the query again with no change. I also have manually run it a couple of times and it works.

I have some pretty visible visualizations built in Grafana that use that measurement, and I can’t keep updating it manually. I even tried converting it to a Kapacitor streaming job, and while I see that Kapacitor gets the points and does something with them, the last step (writing to the new measurement) shows zero points processed.

I’ve Googled this a number of times and not found anything that lines up with my issue. I’m sort of at my wits’ end here.