[squid-users] Bad Connection & Round Robin DNS

[Garri Djavadyan]

On Tue, 2016-11-22 at 03:59 +0000, Jiann-Ming Su wrote:
> If a website has two (or more) IP addresses, and the TCP connection
> to one of them fails, can squid3 be configured to try the other IP
> address(es)?

Hi,

The behavior you described is default for Squid. For example, you can
set 'debug_options ALL,1 14,9' to confirm it:

2016/11/22 09:47:50.426 kid1| 14,3| ipcache.cc(433) ipcacheParse:
ipcacheParse: mail.ru #0 [2a00:1148:db00:0:b0b0::1]
2016/11/22 09:47:50.426 kid1| 14,3| ipcache.cc(422) ipcacheParse:
ipcacheParse: mail.ru #1 94.100.180.199
2016/11/22 09:47:50.426 kid1| 14,3| ipcache.cc(422) ipcacheParse:
ipcacheParse: mail.ru #2 94.100.180.201
2016/11/22 09:47:50.426 kid1| 14,3| ipcache.cc(422) ipcacheParse:
ipcacheParse: mail.ru #3 217.69.139.199
2016/11/22 09:47:50.426 kid1| 14,3| ipcache.cc(422) ipcacheParse:
ipcacheParse: mail.ru #4 217.69.139.200
2016/11/22 09:47:50.426 kid1| 14,9| comm.cc(646) comm_connect_addr:
connecting to: [2a00:1148:db00:0:b0b0::1]:80
2016/11/22 09:47:50.427 kid1| 14,2| ipcache.cc(924) ipcacheMarkBadAddr:
ipcacheMarkBadAddr: mail.ru [2a00:1148:db00:0:b0b0::1]:80
2016/11/22 09:47:50.427 kid1| 14,3| ipcache.cc(889) ipcacheCycleAddr:
ipcacheCycleAddr: mail.ru now at 94.100.180.199 (2 of 5)
2016/11/22 09:47:50.427 kid1| 14,9| comm.cc(646) comm_connect_addr:
connecting to: 94.100.180.199:80
2016/11/22 09:48:50.036 kid1| 14,2| ipcache.cc(924) ipcacheMarkBadAddr:
ipcacheMarkBadAddr: mail.ru 94.100.180.199:80
2016/11/22 09:48:50.036 kid1| 14,3| ipcache.cc(889) ipcacheCycleAddr:
ipcacheCycleAddr: mail.ru now at 94.100.180.201 (3 of 5)
2016/11/22 09:48:50.036 kid1| 14,9| comm.cc(646) comm_connect_addr:
connecting to: 94.100.180.201:80
2016/11/22 09:49:50.091 kid1| 14,2| ipcache.cc(924) ipcacheMarkBadAddr:
ipcacheMarkBadAddr: mail.ru 94.100.180.201:80
2016/11/22 09:49:50.091 kid1| 14,3| ipcache.cc(889) ipcacheCycleAddr:
ipcacheCycleAddr: mail.ru now at 217.69.139.199 (4 of 5)
2016/11/22 09:49:50.092 kid1| 14,9| comm.cc(646) comm_connect_addr:
connecting to: 217.69.139.199:80
2016/11/22 09:50:50.152 kid1| 14,2| ipcache.cc(924) ipcacheMarkBadAddr:
ipcacheMarkBadAddr: mail.ru 217.69.139.199:80
2016/11/22 09:50:50.153 kid1| 14,3| ipcache.cc(889) ipcacheCycleAddr:
ipcacheCycleAddr: mail.ru now at 217.69.139.200 (5 of 5)
2016/11/22 09:50:50.153 kid1| 14,9| comm.cc(646) comm_connect_addr:
connecting to: 217.69.139.200:80


Garri