On Mon, Jun 7, 2010 at 08:44, Craig Ringer <craig@postnewspapers.com.au> wrote:
> On 07/06/10 10:29, John T. Dow wrote:
>> One of my clients is getting this problem occasionally. Actually, we
>> can cause it to happen quite reliably by pasting certain text into a
>> couple of fields, but the vast majority of text entered into the vast
>> majority of fields causes no problem.
>
>> I've read enough to suggest that AV software might be the culprit.
>> It has been said that it is not sufficient to exclude the database
>> directory nor even to disable to AV protection, it has to be removed.
>
> Depends on the AV software. That advice is general, and is given because
> _some_ antivirus software is badly written and fails to properly exclude Pg.
Actually, the issue isn't that they "fail to properly exclude postgres".
The issue is that they insert filtering functions in the Windows API,
that *breaks the Windows API*. The reason this is often not noticed on
other products before PostgreSQL is that PostgreSQL uses a
multiprocess architecture, and this is specifically the case where
they fail. This is uncommon in the extreme on Windows. In fact,
Microsoft has (or at elast used to have) examples up on their MSDN
site that break in this case.
> Some AV software probably behaves fine.
Probably.
>> The problem is, their database server is also a file server. As a file server it must have AV protection. The server
isrunning Windows Server 2003 I believe. It has RAID etc. My client's antivirus software is AVG (paid, not free).
It's generally a mistake to put a fileserver on the same machien as a
database server, if you want any kind of performance for either one of
them. But if you don't care about performance at all, it's a fairly
sensible move, yes.
>> Question: Is AV software still regarded as the likely culprit?
>
> Likely enough - especially for intermittent issues - that the best thing
> to do is uninstall it, reboot, and re-test to see if the issue remains.
>
> If you can reproduce it without the AV software then it's worth
> investigating further.
Yeah. And if it does go away without the AV you at least know what the
problem was. You can then decide if you want to try a different AV, or
if you want to look at perhaps running pg in a virtual machine on the
box.
> It'd be interesting if someone with a paid contract for AV support would
> go to their AV vendor and get them involved. With the active
> co-operation of an AV vendor or two and a reproducible fault, some
> progress might be possible.
Yes, that would be very useful.
--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/