On Fri, Mar 27, 2009 at 10:03, Justin Mason <jm at jmason.org> wrote:
> On Fri, Mar 27, 2009 at 10:00, Kae Verens <kae at verens.com> wrote:
>> Kae Verens wrote:
>>>>>> Kenn Humborg wrote:
>>> >> On Thu, Mar 26, 2009 at 5:04 PM, Kae Verens <kae at verens.com> wrote:
>>> >>> all was running perfectly for months until today.
>>> >> Any patches applied? Anything showing on the logs? Tried to restart
>>> >> services/box ?
>>> >
>>> > Run strace -p <PID> on the server process. It might provide
>>> > clues as to what's going on during the delays.
>>>> turns out that another guy in our datacentre is having the same problem, so
>> this may be a router problem.
>>>> any ideas why it would mostly affect POP3? appears to be slowing our other
>> services, but POP3 is the most serious.
>> this looks to me like the kernel buffers are filling up, returning the
> EAGAIN ("try again later" basically) to the app level. have you
> considered it may be a broken QoS policy or similar on the router
> deprioritising POP3 traffic?
hmm. also, when small packets get through fine but large packets
have trouble, that smells like MTU issues.
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!
