Monthly timeline view missing for recent months

When I select Monthly for the Timeline view option, I have no records plotted for March or April and what looks like a partial record for February. Looking at January 2021 and the few months previous all looks as I’d expect. Is there a known issue? Daily and weekly look fine while Annual is missing the February to April data. I spend a reasonable amount of time in the app so I would have assumed it would have caught up with this by now? A work security profile policy means the phone has a fairly aggressive screen lock so I can’t leave it unlocked for a long time without removing that profile…


Monthly summaries are created in an iOS background job which is simplifying the detailed data, to allow the display of so much data in one view.
The background job runs when iOS permits it, while the device is powered (idk if wifi plays a role too) and the app is in background. It sometimes helps to restart the phone and swipe-close all other apps.

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Yeah, unfortunately the data collation needed for the monthly and yearly maps often gets behind, due to iOS not allowing Arc to run its housekeeping background tasks for long enough each day. It’s up to iOS to decide when it runs those tasks, and for how long it lets them run for. Typically it terminates the tasks before they finish.

I started experimenting last week with running the SimpleItem updates while the app is in the foreground and plugged in to power, on an on-demand basis, when viewing monthly/yearly map views. It now looks for missing SimpleItems, and starts building/updating them as needed, to fill in the map.

It will only do this when the phone is plugged in to power, and it’s potentially a whole lot of data shuffling in one go, so it runs the risk of iOS getting angry and terminating the app. But it at least gets the job done much faster, and prioritises doing the date ranges that you’re actively trying to view on the map.

I should have the next Arc update ready in … well, hopefully this week, if I’m lucky. It’s going to be the first public release that uses the new backups system, so I have to step carefully and make sure I haven’t made any mistakes. The backups system is a major subsystem with a lot of moving parts. But yeah, it’s looking hopeful that I might be able to get the update out this week. Fingers crossed!

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This explains what I’m seeing and your improvement sounds like it should help. I’ve removed the work profile (I’m on holiday for a week), removed the screen lock and then let Arc run in the foreground overnight while plugged in and it seems to have made no difference to the monthly maps. If it’s only doing that collation while in the background then that explains this. Would having a slightly older phone (XR) also mean there’s less capacity to run tasks in the background?

Apple’s documentation suggests that the tasks are only run in the background, but in practice we’ve seen them running even when the app is in the foreground. But there’s no reliable way to predict when iOS will decide to run the tasks. Arc’s part of the process is to register the tasks then schedule them (in the sense of “I would like the task to run now” or “I want the task to run in an hour from now”). Beyond that it’s anyone’s guess. And Arc’s scheduling has little to no impact on how soon tasks get to run (asking for “immediately” is like wishing for the tooth fairy to be real, and “after an hour” isn’t much better).

Maybe very slightly. But the XR isn’t really all that old. It’s got a fairly recent CPU, with six cores, so is still quite powerful, and also has fairly decent battery life. My iPhone 11 also struggles to keep up with the various daily background tasks that need to run, even though I tend to get excellent battery life each day. So I think it’s more down to iOS just being very frugal about how much time it allots out to apps to run their scheduled tasks.

Aside: All of these background tasks that Arc needs to run are also registered as “needs power”, ie the task should only be run by iOS while the phone is plugged in to power. So that means that the task is explicitly not a burden to battery life, and shouldn’t be restricted on energy use grounds. But… that still doesn’t help with getting iOS to run the tasks more often or for longer. It’s a bit of a losing battle! :man_shrugging:t2:

Anyway, at least the next Arc release will take care of getting the monthly/yearly maps filled in. It might result in the occasional extra crash while viewing those maps, if iOS gets angry about too much CPU work being done. But that’s still better than waiting weeks before you can see the maps!

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