DTTG freezes when reading pdfs and wifi on

The issues with pdf editing (“the line”) in 2.7.7 have been reported and confirmed. However, I’ve had another issue that does not seem to be brought up here. When I open a multi-page pdf, almost invariably, after a minute or so of reading, DTTG freezes and I have to restart the app. First I thought this was connected to very large pdfs with many pages, but it also happens with rather short ones (probably I often don’t look long enough at them for the freeze to kick in). I noted that the little progress-circle next to the wifi icon in the status bar keeps spinning after the freeze occurs. If I disable wifi (no cell on this iPad), the freeze does not occur. I have an excellent wifi connection, and no other app has the slightest connectivity issue. While I cannot prove it, it is suggestive that DTTG is trying to access the net and hangs. It never seems to occur when I don’t view a pdf.

Just like the pdf editing issue, this has appeared under 2.7.7. Is anyone else observing this?

Running on an iPad Air 3 under iPadOS 13.3.1.

Update: still the case under 13.4.1. This also happens on my iPad Pro 12.9 (2015). Not just just a matter of a specific iPad model (but could still specific to my databases). And disabling the wifi AFTER DTTG gets stuck does not bring response back.

Update2: With exactly the same databases present, and reading the same pdfs, this does NOT seem to occur on the iPhone X.

Currently I don’t see this behavior here but it might be related to the synchronization. Di you sync directly via Bonjour or via a sync store on iCloud/Dropbox/WebDAV?

Hi, Thanks for looking into this. I am using a sync store via iCloud. Have been doing this for a long time, and it works very well. I never get any hangs unless I’m in pdf for a while (minute, sometimes several minutes). This only appeared recently (2.7.7?). I remember that with the previous version of DTTG, scrolling through large pdf would feel laggy (which on the same iPad and older ones was, with the same documents, not an issue before). So i was relieved when the release notes for the new version said “improved handling for large pdfs”. Someone even posted here, confirming the improvement. Well, for me that never materialized, in fact it got worse.

One thing that changed recently, around the time of 2.7.7. is that I added a whole bunch of pdf books to my Global Inbox as part of having to work from home. Some are 10s of MB, most are a few MB. So maybe my inbox DB got too unwieldy? (Inbox: 3 GB, unique words 420k, total words 25M)

That fact that no one has responded to my post with similar observations indicates that this issue might be specific to my local situation. I note that it happens on iPad Air 3 and iPad Pro 12.9 (2015) alike, so it’s not particularly device specific. But they both sync to the same DBs via iCloud.

Ideally, I should remove my DBs from one of the iPads, then load a modest DB with some of those pdf books, and see whether this issue still persists. Only problem, I desperately have to wind down my semester tasks this week, so I’m not fiddling with any of my devices for now. Next week I’ll look into this and report back.

Do you know how many PDFs you added, roughly?

Maybe 30? Nothing crazy. Given what DT and DTTG have been handling all along for me, I was not suspecting that this would be a problem. Btw., Eric is in touch with me about some potential issue that might cause this.

Okay. I added 66 PDFs here and am not seeing any odd behaviors. Cheers!

Eric set me up with the 2.8 beta. The iPad no longer freezes, but still stalls for seconds at a time while scrolling pdfs or annotating pdfs with the Apple Pencil. When I disable DTTG iCloud sync, everything is absolutely smooth and trouble-free. Feels like sync routines move in too heavily, either stealing too many CPU cycles momentarily, or otherwise halting the program flow.

Hi - I have the same issue. The screen freezes, sometimes in mid-page transition when scrolling through pdfs. The problem is intermittent. Turning on aeroplane mode seems to help. I sync via Dropbox.

Does it only happen for PDFs or also other document formats?

Thanks very much for coming back to me, Eric - I’ve only noticed it with PDFs. I do a lot of highlighting and annotating.

Are the PDFs large? It could be related the auto-saving of the PDFs.

I was wondering about that. I get the lag (2.8b) or freeze (2.7.7) with pdfs for sure, especially large ones, and now apparently also with website, but I can’t make it work with Word docs. The latter are only previewed inside DTTG, so there is no information that would need to be written out for sync due to scrolling through such document.

I can’t say for sure (can’t remember how big the documents were that I was working on when it has happened) but probably, yes - the pdfs can be anything up to 150MB.

I’ll try to note when it happens from now on and see if there’s a pattern.

the pdfs can be anything up to 150MB.

150MB is an unusually large size for PDFs.

150MB is an unusually large size for PDFs.

Indeed, but there are some books that big. I have severals ones in the 10s of MB range. But the point is that current iPads and the pdf renderer in DTTG and other pdf readers have not the slightest issue with such files. All my pdfs work without a hitch in DTTG as long as sync to iCloud is disabled. Possibly, DTTG is trying to auto-save the file or updating some related metadata and is allotted too much resources for a moment or several.

I know - court book exhibit folders (can’t avoid it, unfortunately).

That is what I suspect too. We’ll investigate and try to reproduce this issue. Would you, maybe, be able to share one of these large PDFs with us for testing purposes (content doesn’t matter, we’re just interested in the effect the document it has).

Hi Eric, I messaged you a link to a large pdf file. But the nature of this beast is complicated. Starting yesterday, I noted that things are smoother.

iPad Air 3: after installing 2.8b on Wednesday, I did not get any (restart app level) freezes while working with pdfs, but very frequent lags that lasted several seconds (both on scrolling and annotating). Today, I’ve used two large pdfs that gave me these issues, and lo and behold, things are much smoother, basically no lags at all while reading (i.e. slowly scrolling). But I still get periodic, few second lags, while annotating with the Apple Pencil (so annotating with wifi on would still be nerve-wracking, it’s like taking live notes with an intermittent ball pen, it’s torture).

iPad 12.9 (2015): still running on 2.7.7. After opening the document it sent to you, within the first minute I got a restart-level freeze, but after that for many minutes only second-level lags while reading, but no further freezes. Over the past weeks, with 2.7.7, freezes came one after another.

Not sure what changed over the past days.

Update: I never mentioned this, but when I say “reading pdfs” I should point out that I am always in “continuous scroll” mode, not flipping pages. This naturally puts a bigger load on the device.

So, 2.8 is acting differently, doesn’t freeze the app completely so that you have to kill-and-relaunch it, but still freezes for seconds, presumably when saving annotation data? Does that describe the symptoms?

Yes, that describes it. The lag is also during slow scrolling through the document, not just annotating. Oddly, in the past 2 days the effect was much diminished, without any obvious difference in wifi performance or (at least) apparent load on the iPad (other apps running, Photos syncing etc).