"tcpflags 0x18<PUSH,ACK>; tcp_do_segment" kernel messages

[Stefan Lambrev]

Hello Eygene,

Eygene Ryabinkin wrote:
> Stefan, good day.
>
> Fri, Aug 17, 2007 at 11:04:20AM +0300, Stefan Lambrev wrote:
>   
>> Their response is that the mail server timeout.
>>     
>
> And how they are detecting the timeout?  They are using alarm(),
> just polling for the time with non-blocking read calls, setting the
> socket timeout or something else?
>   
They do not provide such information.
But they have some kind of cronjob to restart the program if the PHP 
script stall, which makes me think
that it is not something very rare in this case.
I'm still waiting better response from their support team and if this 
happened will let you know.
>   
>> Now the question is why the program things that the server timeouts when it 
>> does not :)
>>     
>
> May be this is connected to the socket timeout stuff: chances are
> good that the PHP program uses apr_socket_timeout_set(), so there
> can be issues with SO_SNDTIMEO/SO_RCVTIMEO socket options in the
> -CURRENT.  At least Apache (that I have problems with) sets keep-alived
> sockets with apr_socket_timeout_set().  I will try to have a look
> if this can be true.
>
> Thanks for your information!
>
> Mike, Robert, there are chances that some timeout code behaves
> weirdly.  And maybe the magic number 3 (every 3rd keep-alived
> connection seems to be dropped due to the timeout, Stefan sees it
> too) should be searched in the timeout code.  Maybe you can give
> some hints or point to the exact place where the error can occur?
>
> Thank you.
>   

-- 

Best Wishes,
Stefan Lambrev
ICQ# 24134177