W dniu 2014-02-12 14:11, Amos Jeffries pisze: > On 13/02/2014 1:59 a.m., Pawel Mojski wrote: >> W dniu 2014-02-12 13:54, Kinkie pisze: >>> On Wed, Feb 12, 2014 at 1:49 PM, Pawel Mojski <pawcio@xxxxxxxxxx> wrote: >>>> W dniu 2014-02-12 13:30, Kinkie pisze: >>>>> On Wed, Feb 12, 2014 at 12:40 PM, Pawel Mojski <pawcio@xxxxxxxxxx> 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? > Whether or not that is right the ERR_CONNECT_FAIL is only produced on > SYN errors. > > If Squid were able to connect but no HTTP response it would be a > ERR_READ_ERROR, ERR_READ_TIMEOUT or ERR_ZERO_SIZE_OBJECT. > > Amos Thanks Amos; Now I know what is wrong and have to figure out why. So, if it's not squid related problem I'll not boder you any more with this case. Best Regards; Pawel Mojski
