[syslog-ng]syslog-ng 1.5.25 released

[Ted_Rule@flextech.co.uk]

>From "Stevens'" great Unix Network Programming bible ....


"Traditionally , System V has returned the error EAGAIN for a non-blocking I/O
operation that cannot
be satisfied while Berkeley-derived implementations have returned the error
EWOULDBLOCK.
To confuse things even more, Posix.1 specifies that EAGAIN is used while
Posix.1g specifes that EWOULDBLOCK
is used. Fortunately, most current systems ( including SysV and 4.4BSD ) define
these two error codes to be the
same ( check <sys/errno.h ), so it doesn't matter which one we use. In this text
we use EWOULDBLOCK, as specified
by Posix.1g"



Dontcha just lurrv so many standards....


Ted






Balazs Scheidler <bazsi@balabit.hu> on 24/01/2003 09:03:25

Please respond to syslog-ng@lists.balabit.hu

To:   syslog-ng@lists.balabit.hu
cc:    (bcc: Ted Rule/160GPS/Flextech/UK)

Subject:  Re: [syslog-ng]syslog-ng 1.5.25 released



On Thu, Jan 23, 2003 at 07:12:53PM +0100, Roberto Nibali wrote:
> >>Would you care to explain to me this fix, please? As I read it, it only
> >>kicks in in case write(2) returns with a 0. But this 0 doesn't mean 0
> >>bytes have been written, but something else. I'm a bit confused. Keep in
> >>mind that I haven't read your code all too well yet ;).
> >
> >check fd_write in libol/src/io.c, which handles EINTR and EAGAIN and
> >returns 0
> >instead of -1 for those reasons.
>
> I see, thanks for the pointer (I'm surprised EWOULDBLOCK is portable
> enough).

Syslog-ng has been running on a couple of Unixes and nobody complained about
EWOULDBLOCK. I think it is defined as EAGAIN on most platforms.

>
> Additional question: Have you or anyone else done any tests with O_SYNC or
> mounting the log partition with noatime? I'm asking because I'm trying to
> isolate a performance issue on a central loghost.

O_SYNC would certainly increase your load. noatime could help though.
Checking the output of vmstat (disk i/o, swap i/o, system and user cpu time
spent) usually helps locating performance issues.

>
> >thanks for the report.
>
> I should also like to ask you about the status of the template() patch [1]
> done by one of my team mates. He's not working on this project anymore and
> I've taken over. If I get around to fix your concerns mentioned in [2],
> would you still consider it for inclusion into 1.6.0?

yes.

--
Bazsi
PGP info: KeyID 9AF8D0A9 Fingerprint CD27 CFB0 802C 0944 9CFD 804E C82C 8EB1

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