journalctl --follow

[Chris Murphy]

On Mon, Feb 9, 2015 at 11:59 PM, Wolfgang S. Rupprecht
<wolfgang.rupprecht at gmail.com> wrote:
>
> Is journalctl in the tail -f mode called "follow" supposed to be
> realtime?  I'm seeing it more or less output log lines in realtime for
> many hours and then eventually it falls behind with half an hour or one
> hour delay.
>
> The (simplified) lines are from a perl sshd tracker are:
>
>     open( LOG, "journalctl -o short-precise -u sshd --follow |");
>     while (<LOG>) {
>     ...
>     }
>
> I suppose, it is possible that the delay is in perl, but journalctl
> seems more likely to be the culprit, hence the subject line.

I haven't seen this. If you quit and then issue a new journalctl -f,
do you see a bunch of things that previously weren't there with
(approximately) current time? It might be a bug worth inquiring about
on systemd-devel at .

-- 
Chris Murphy