Re: [squid-users] Debuging ERR_CONNECT_FAIL with SYSERR=110

W dniu 2014-02-12 13:54, Kinkie pisze:
> On Wed, Feb 12, 2014 at 1:49 PM, Pawel Mojski <pawcio_at_pawcio.net> wrote:
>> W dniu 2014-02-12 13:30, Kinkie pisze:
>>> On Wed, Feb 12, 2014 at 12:40 PM, Pawel Mojski <pawcio_at_pawcio.net> wrote:
>>>> Hi All;
>>>>
>>>> I have pretty loaded squid server working in interception mode.
>>>> In about 0.5% of total http request I have an ERR_CONNECT_FAIL with
>>>> additional error SYSERR=110.
>>>> How can I debug a reason of those errors?
>>>>
>>>> The thing which consider me a lot is the URL and remote server of those
>>>> requests.
>>>> For example, I found three same requests for the same URL hosted on the
>>>> same IP request.
>>>> The first one finished with response 200, the second with 503 and
>>>> ERR_CONNECT_FAIL(SYSERR=110) and the third with 200 again.
>>>>
>>>> Also, my customers complains that sometimes "they have problems surfing
>>>> the web".
>>>>
>>>> What can I do to debug the problem?
>>> Hi Pawel,
>>> SYSERR 110 on Linux is connection timeout (ETIMEOUT).
>>> It would seem to indicate network issues somewhere, or a severely
>>> overloaded server (which has used all its syn backlog)
>>>
>>>
>> Hi Kinkie;
>>
>> I thought the same, but, I have huge net.core.netdev_max_backlog and
>> net.ipv4.tcp_max_syn_backlog and there are no network related problems
>> at all.
> The error is reported by squid, but the issue is on the origin server, if any.
>
>> At the same time when squid reports a problem I can connect manually
>> from squid box to the same ip address (through telnet, wget, etc) and
>> nothing wrong occurs.
>> I even can belive somewhere somekind of timeout happened but how can I
>> find out what type of timeout it is? syn/ack, wait, whatever?
> It should be waiting for syn/ack.
So. Just to clarify.
From tcp point of view: squid is not able to establish connection with
origin server. Thats all.
After sending SYN packet no ACK is reponded. SYSERR=100 cannot means
that squid was able to connect but no response was returned in some
period of time. Am I right?

Pozdrawiam;
Paweł Mojski
Received on Wed Feb 12 2014 - 12:59:42 MST