On Fri, 6 Aug 2004, SXB6300 Mailing wrote:
RH9 and squid 2.5S1. Too give a little more detail, all the squid proxies (parent and child) arrive on the same switch, so I really don't think it's a network issue.
If you see TCP connection failed messages then there is very few possible causes:
a) The peer is not running, either due to manual action or unexpected restart. Seen in cache.log.
b) The peer is not accepting any new connections due to running out of filedescriptors. Seen in cache.log.
c) Network connectivity is poor causing a lot of dropped packets. For example if full/half duplex negotiation between server and switch is wrong or bad cables. Usually seen in ping as packet loss but easier to detect by network testing (netperf or similar).
d) SYN backlog is full on the peer, possibly from someone SYN flooding it or if there is very many dialup / wan type clients accessing it (large latency client<->server). Not easily seen unless it gets very far where the kernel may warn about a possible SYN flood..
Regards Henrik
