Does Sleep Prevent Syncing?

[ryantate]

I've seen several posts in this forum that imply that Bittorrent Sync does not function if either of two peers is "sleeping."

 

This topic is not addressed in the FAQ or (rather thin) "User Guider," "Desktop Manual," etc.

 

So to be clear: Can anyone state authoritatively if both of two personal computers need to be "awake" in order to Sync? (If OS matters, I'm asking about OS X 10.9.1.)

 

If so, this should be stated somewhere in the docs, as it is common to want to sync a home computer to  a work computer. Typically, one of the two machines will be asleep. It's not rocket science to prevent my home Macbook from sleeping but it never occurred to me this might be preventing sync.

 

This would also be surprising. My BitTorrent  client (Transmission) functions fine during sleep, for both uploading and downloading, as do two other file transfer systems, CrashPlan and Dropbox. 

 

Thanks for any guidance.

Edited February 6, 2014 by ryantate

[nils]

Hello Ryan,

 

I am not quite sure how a sync should work, if one of the clients is asleep. With BTsync, you cut out the middleman: e.g. in Dropbox you have a centralised server, with which you sync. You do not have this with BTsync. In BTsync, the only nodes that will share data with each other, are the ones that have the same secret.

 

In a case of having only two nodes i.e. work and home, you would need a third device, if you want to allow any of the two to sleep. Data will not be synced, if the work computer sleeps and you have only your home laptop on.

 

HTH

[ryantate]

Nils: Here's what happens during sleep on OS X http://support.apple.com/kb/ht2412

 

As you can see by default the computer is supposed to "wake for network access" during sleep, which is why, as you ignored from my previous post, Transmission maintains Bittorrent downloads during "sleep" (technically, probably display sleep + active CPU, but indistinguishable by the user). 

 

If Bittorrent Sync does NOT wake OS X for network access, that  should at least be in the docs (and seems like a bug as well). I'd love to hear from someone from BT (and I assume you're not from BT) on whether Sync is supposed to work on OS X when one of the nodes is "sleeping" with "wake for network access" checked.

Edited February 6, 2014 by ryantate

[Firon]

Wake for network access is wake-on LAN to send magic packets to wake the machine up. It has nothing to do with preventing the machine from going to sleep to keep your programs running.

Sleep is sleep - the machine is doing nothing when it's sleeping.

 

Power nap, on the other hand, is what allows a background program to wake the machine and run when the machine is 'sleeping' (it wakes temporarily to run, though only partially). But only specific Apple software can use that.

[GreatMarko]

So to be clear: Can anyone state authoritatively if both of two personal computers need to be "awake" in order to Sync? (If OS matters, I'm asking about OS X 10.9.1.)

 

Yes, if you're syncing between two computers only, they both need to be awake and online for syncing to take place between them.

[ryantate]

OK, thanks for the clear answer.

 

I'd really appreciate it if you were more clear about this in your documentation. Nowhere is this stated, and I wasted a lot of time combing through debug logs. (The problem sporadically seems to resolve itself, I guess my work computer likes to wake itself up sometime.)

 

Given that systems like Dropbox and Bittorrent downloads work fine from sleep, or work around the issue of sleep in a way that is totally transparent to the user, you really should clarify this, as people will expect your system might work similarly. (I understand the technical reasons why this might not be possible for BT Sync -- there's no always on central server, by design -- I'm just saying you should make things clear for new users.)

[nils]

I'd really appreciate it if you were more clear about this in your documentation. Nowhere is this stated, and I wasted a lot of time combing through debug logs. (The problem sporadically seems to resolve itself, I guess my work computer likes to wake itself up sometime.)

BTsync is still considered beta, therefore nothing is set in stone i.e. documentation changes, API changes etc.

If you would like to see the sleep behaviour you are describing implemented, put it on the long wishlist so that the devs can pick it up. Or if you think it is a bug, put it on the bug list.