#10363 NORM 10.1.3: Auto-Suspend gets in the way when sharing over Salut

[Tomeu Vizoso]

On Mon, Sep 20, 2010 at 12:56, Paul Fox <pgf at laptop.org> wrote:
> tomeu wrote:
>  > On Thu, Sep 16, 2010 at 23:38, Martin Langhoff
>  > <martin.langhoff at gmail.com> wrote:
>  > > On Thu, Sep 16, 2010 at 5:05 AM, Tomeu Vizoso <tomeu at tomeuvizoso.net> wrote:
>  > >> So the problem is that if you had to resync all state for each machine
>  > >> every time they wake up, you would use lots of bandwidth with the
>  > > (...)
>  > >> Another issue with this is that you not only want to resync presence,
>  > >> but shared activities also would need to resync their state.
>  > >
>  > > Correct. My notes on the bug are probably unreadable -- it was late
>  > > last night, apologies.
>  > >
>  > > What I mean to say is that we could
>  > >
>  > > 1 - explore the interaction between sleep timeouts and Salut resync
>  > > frequency for presence
>  > >
>  > > 2 - hack the Tubes/Telepathy stack to _prevent sleep_ while an actual
>  > > collaboration session is running
>  > >
>  > > I think #1 needs to be done regardless, as it'll improve behaviour
>  > > even if/when we our networking/suspend issues sorted. And some of the
>  > > issues in network/suspend interaction won't be easy to resolve.
>  >
>  > I doubt there's much that can be done in Salut about it, should be
>  > instead done inside Avahi. I would see how mDNS works, then look for
>  > opportunities of tuning knobs in Avahi to speed up rediscovery:
>  >
>  > http://tools.ietf.org/html/draft-ietf-dnsext-mdns-47
>  >
>  > I'm going to ask around in case somebody has already thought of it and
>  > can provide a shortcut.
>
> the laptop knows how long it was suspended, and this information could
> be made available to a resume hook (which almost exists, but not
> quite, in powerd) if it would be useful.  i.e., a a post-resume script
> could decide whether to kick the protocols to do something differently,
> if that was needed.

Pinged Lennart in #fedora-desktop and he said that if avahi isn't
trying harder to update its state after resuming it's because there
isn't a decent hook for that in Linux yet.

I couldn't get from him any other useful information, but maybe this
is a chance to explore ways in which Avahi can update itself faster
after sleep? If there's interest, I think this should be moved to the
avahi list.

Regards,

Tomeu

> paul
> =---------------------
>  paul fox, pgf at laptop.org
>