Bingo.

It started with my laptop running incredibly slow. A bit of digging showed dropbox saturating an entire cpu core despite no recent changes being made to my dropbox folder. What was happening at the time is a lot of disk activity on a folder that Dropbox should know nothing about. I'm not 100% sure but it also seems to me that Dropbox is monitoring all FSEvents on my machine and doing something with them.

I've been a paying Dropbox user for several years, but this has tipped me over the edge. The only way to regain my trust at this point is providing an official explanation of what's going on, with technical details. I'm paying for a service to keep my files safe and sync them across devices, nothing more, nothing less. Now that I got the impression that Dropbox is doing something outside of that envelope, even if that impression is wrong, my money is going to go elsewhere, probably to a competitor.

I feel bad for contributing to the hijacking of this thread, but I simply have to pitch in: please do something about the abysmal performance of Dropbox. We have what are practically supercomputers on our desks, and Dropbox has problems dealing with hundreds or low thousands of files. It is something you need to work on.

As to the original article, I think you have a lot of explaining to do and a lot to clean up. Too much has been swept under the rug.

Just checked this myself on a MacPro. You can see the DropBox process kick in with CPU usage while opening big apps like Photoshop or Xcode. Not a lot on this MacPro (~3%), but it's always in time with an app opening. Oddly there's no corresponding disk access associated with the Dropbox process when looking at it on the Disk tab of Activity Monitor.

Would definitely like an explanation of what's going on here.

Could this be a consequence of the built in FS APIs coming up short, as Ben put it, and forcing DropBox to do things in less efficient ways to work around the limitations?

Doesn't Apple literally have a sync solution on this platform, likely using these same APIs? FSEvents powers a lot of core functionality on macOS so it's surprising to hear it just doesn't meet Dropboxes needs.

It's cool they are moving into the kernel soon anyway, just install their kext...

Is Apple's sync reliable though? There was an episode of MacBreak Weekly last week where both Adam Engst & Andy Ihnatko urged people not to enable the new Sierra sync system, and talked about instances of data loss caused by Apple's various sync features. The segment begins here:

https://www.youtube.com/watch?v=IgE1c-YTEpE&t=65m02s

I thought it was common knowledge that Apple's own sync (nevermind the APIs they provide to third parties) was terribly unreliable. Even long-time Mac developers like Panic & Omni developed their own sync services because the Apple ones were so unreliable.

That and what I take to be the iCloud / System Indexing daemon's (like `mdfind`) kill my battery life. The other's reports of poor Dropbox performance baffles me a bit as it never seems to give me issues, but iCloud/Google Drive both have both had big performance penalties on 3 various macs I've tried them on.

That's also my experience - I tried using OneDrive & Bitcasa at various times, and found they used far more battery than Dropbox ever did. I'd consider switching from Dropbox, but the competitors seem inferior to me (and Dropbox has more universal support).

I can't fathom why you think them being a kext is a good thing. I refuse to use anything anymore that needs that, every app that needs that inevitably is a source of something breaking in OS X

Was complete sarcasm

What do they need different from what time machine uses?

Time Machine needs to be able to ask which files changed when it is preparing to backup. Dropbox needs to be notified when a file changes so it can sync.

Have you checked the version of the Dropbox client you're running? The auto-updater broke and silently failed many months ago (n=5 Macs) and I found a number of problems like that one had already been fixed but effectively never shipped.

(Support was prompt but basically “let us know if it happens again”)

I started to see this really happen when backing up. When Arq is doing some work, Dropbox is slamming the CPU. I checked with the Arq team and they said during the time I was monitoring it, there's no way they would be touching the Dropbox folder, so it really did seem like some kind of global intercept was going on and was killing the box. I guess this is as good a way as any to raise this -- Dropbox team, test with Arq!

Same problem. When working with or moving files in folders other than the dropbox folder, I still find the dropbox application taking up large amounts of CPU. Dropbox also, in the last few months, has been messing up my spotlight database and causing mdworker and fontd to use all available cpu.

Then I start getting console messages like this: mds (Error) FMW: WE ARE DROPPING FMW EVENTS!

All disappears after disabling Dropbox (and rebuilding caches and the spotlight database)

Behaviour seen on multiple macs I own.

I uninstalled the desktop client because of this exact issue. I just drag/drop via the web interface now. Might not work for some people, but it suits me fine.

Just uninstalled too. I was only using it for syncing 1password data and this pushed me to just switch to a 1pass account

1password has had iCloud syncing for a while now, and in my experience, it's been very reliable.

If you think they are so nefarious a company, why do you trust them with your files?

Didn't say they were nefarious—just that their software hogs resources at times when it has no business doing so (i.e., when I'm not reading from or writing to my Dropbox folder).

As important as this question is for usability, it seems off the original post's topic of Dropbox circumventing accessibility prompts.

Same problem here. My 3 year-old i5 Retina MacBook Pro is often slow because Dropbox uses 100 % of one CPU. And it gets hot too …

I noticed a lot of disk activity once and fired up Process Monitor (on Windows). Dropbox.exe was going through literally all the files on my computer. That was when I uninstalled it forever.

Yeah, I'm more curious as to why Dropbox corrupted a few of my PDFs. Has been happening for years for a variety of people.

If you see this happen, please write in to our support team; we take data integrity issues very seriously.

Also I should probably mention that we keep 1 month of version history for free users and even more history for paid users, so if the corruption is recent you should be able to undo it yourself. But please report either way.

(Full disclosure: I work for Dropbox).

I'm a huge fan of Dropbox and I pay a monthly fee. I probably don't need to as my data needs aren't huge, but you guys are frankly the first people I've used that did this sort of thing properly and I believe you are worth paying a subscription fee to.

I'll log a ticket :-) might need to reproduce the issue first. Pretty awesome that you have employees who respond to posts on HN incidentally, that automatically increases my loyalty to a company several notches!