As too often happens, with the new year comes a number of things we forget to do. For many of us, it used to be writing dates, where we'd put last year for a while. Same idea, but things that only change annually sometimes need to be hunted down.
I've got log collection and analyzers that aggregate the logs and let me see patterns of traffic, potential abuse, and search for curiosities.
For many of the system logs, I just let them go to their usual places and have the log rotation move them out of the way when they get too big or too old. For some of the logs, I divide them up with a date component, to keep them separated and not lose some of the history.
It took looking at one of these aggregations and seeing that there weren't any entries to kick me in gear. Ripping through my head was "how can this be down and not get any alerts," because of monitoring. And then the correct "whoops, forgot the year changed" idea prompted me to fix the configuration.
Logs are aggregating correctly now.