My OSM data now comes from Open Planet Data. Every day at 1am Eastern, the newly provided planet file is downloaded/filtered/loaded. This seems to take 1.5 - 2 hours. During the last amount of that (guesstimating at about 40minutes or so), city syncing is disabled.
If a city has already been synced with “today’s” data, another sync will not run - it will instead respond with “ This city was already synced with the available data”.
After the next ~3am Eastern, because everything gets updated daily at 1am Eastern and the process takes 1.5 - 2 hours to complete.
Yeah, this is because one of the speed-ups I added ended up incorrectly missing some activities for processing after the sync. I had to remove that, and leave it in its slower state until I can come back and review it again.
Post syncing processing is slowing things down, and people are using the manual sync feature way more than they did before I started this project.