Re: Log rotation

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > What versions of syslog fsync, and where is the syslog.conf option. I
> > don't see it on FreeBSD or Linux.
> 
> It's a per-output-file option.  My Linux manpage for syslogd quoth
> 
>       The - may only be used to prefix a filename if you want to omit
>       sync'ing the file after every write to it.
> 
> I believe this notation is inherited from BSD.  I don't see anything
> about it in the HPUX man page for syslogd, though.

I see no mention of that flag in Free/NetBSD, or bsdi. I do see a
mention in Red Hat 9.

Looking at my syslog source code, the only lines that get fsync'ed are
lines from /dev/klog (kernel log messages).  I think non-kernel messages
use the /var/run/log socket.

syslogd manual page says:
    Syslogd reads messages from the LOCAL domain socket /var/run/log, from an    Internet domain socket specified in
/etc/services,and from the special    device /dev/klog (to read kernel messages).  Messages received on the In-
ternetand LOCAL domain sockets may be NULL terminated and may include a    single trailing newline, any other
non-printablecharacters are encoded    into a visible representation by strvisx(3).
 

I wonder if this fsync for PostgreSQL messages is some change made to
Linux syslog.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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