gpg: failed to create temporary file '/var/lib/lurker/.#lk0x57653100.hantslug.org.uk.17897': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Tue Mar 10 14:37:13 2009 GMT
gpg: using DSA key 20ACB3BE515C238D
gpg: Can't check signature: No public key
On Tue, Mar 10, 2009 at 02:33:06PM +0000, Victor Churchill wrote:
> This has me really puzzled.
>
> I have an Apache setup to write a custom_log with the %D field to tell
> me the server response time for each request. And I am seeing a very
> strange pattern.
>
> It seems that for one particular client IP address, when the page they
> are being served includes a particular image, the server frequently
> times out delivering the image. The image is fine served to other
> clients; the client IP gets fine response on (some) other pages. It's
> not particularly big.
[snip]
> So :
> - one image file accounts for almost half the server timeouts;
> - more than half the timeouts come serving this one address;
> - the image times out 40% of the time it is served;
> - 2/3 of the time this image is served it is going to this one user;
> - this user experiences timeouts on 10% of hir page hits;
> - s/he calls up the meter page with this image 15% of hir page hits.
>
> But correspondingly, the user gets OK responses on other pages, the
> image is OK going to other userrs, we get timeouts for other users
> doing other stuff.
>
> This has me quite bewildered. This user may be operating behind some
> corporate firewall router, I don't know. I set up a trial where I
> hammered the server overnight pulling this one image repeatedly from a
> couple of addresses, and had responses consistently around 0.1 second.
>
> What on earth would cause this set of results?
My best guess: They've got a bad MTU set up somewhere, and their
system breaks on large packets that get fragmented. I've had this
myself in the past.
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- A gentleman doesn't do damage unless he's paid for it. ---
