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? Pozdrawiam; Paweł Mojski
