[systemd-devel] [systemd-commits] src/timesync

[Zbigniew Jędrzejewski-Szmek]

On Wed, Feb 04, 2015 at 06:24:13PM +0100, Lennart Poettering wrote:
> On Wed, 04.02.15 18:18, Zbigniew Jędrzejewski-Szmek (zbyszek at in.waw.pl) wrote:
> 
> > On Wed, Feb 04, 2015 at 06:10:40PM +0100, Lennart Poettering wrote:
> > > On Wed, 04.02.15 17:09, Zbigniew Jędrzejewski-Szmek (zbyszek at in.waw.pl) wrote:
> > > 
> > > > On Wed, Feb 04, 2015 at 08:06:44AM -0800, Lennart Poettering wrote:
> > > > >  src/timesync/timesyncd-manager.c |    4 ++--
> > > > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > > > 
> > > > > New commits:
> > > > > commit 7e3254b3bae19221afefdb87b61ff92c755fd2f4
> > > > > Author: Lennart Poettering <lennart at poettering.net>
> > > > > Date:   Wed Feb 4 17:00:23 2015 +0100
> > > > > 
> > > > >     timesyncd: downgrade more log messages from LOG_INFO to LOG_DEBUG
> > > > >     
> > > > >     https://bugs.freedesktop.org/show_bug.cgi?id=87505
> > > > >     
> > > > >     Let's make timesyncd less chatty.
> > > > > 
> > > > > diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c
> > > > > index d3c62c9..223671c 100644
> > > > > --- a/src/timesync/timesyncd-manager.c
> > > > > +++ b/src/timesync/timesyncd-manager.c
> > > > > @@ -285,7 +285,7 @@ static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents
> > > > >          }
> > > > >  
> > > > >          /* resync */
> > > > > -        log_info("System time changed. Resyncing.");
> > > > > +        log_debug("System time changed. Resyncing.");
> > > > >          m->poll_resync = true;
> > > > >  
> > > > >          return manager_send_request(m);
> > > > > @@ -740,7 +740,7 @@ static int manager_begin(Manager *m) {
> > > > >                  m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
> > > > >  
> > > > >          server_address_pretty(m->current_server_address, &pretty);
> > > > > -        log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string);
> > > > > +        log_debug("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string);
> > > > >          sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string);
> > > > 
> > > > Hm, but isn't the problem elsewhere? The bug report stated that ipv6
> > > > router advertisements cause timesyncd to resync, spamming the time servers.
> > > 
> > > Indeed. Reopened.
> > > 
> > > Not sure what the right approach here is though...
> >
> > Maybe we should just set a flag and ignore network changes until the
> > normal time for the next sync comes, if we were already sucessfully
> > synced.
> 
> Hmm, what about this:
> 
> - If we managed to get a successful sync, don't act on the event, just
>   wait for the next normal resync
That's what I meant.

> - If we did not manage to get a successful sync, try again
>   immediately, but not any more often than once per 10s or so...
I think we should fall back here too, maybe more slowly. In case we can't
connect, we shouldn't spam the network too much.

> I think this should make the thing pretty robust and responsive to
> network changes when necessary, but not flood the network needlessly?

Zbyszek