Re: strange errors

Willy Tarreau schrieb:
> Hi Corin,
>
> On Tue, Dec 04, 2007 at 09:42:43PM +0100, Corin Langosch wrote:
>
>> hi marc,
>>
>> yes, netfilter with conntrack is running. I saw errors some weeks ago,
>> but i fixed them with:
>>
>> echo "Tuning network settings according to haproxy..."
>> echo 1048576 > /proc/sys/net/ipv4/netfilter/ip_conntrack_max
>> echo 2000 60000 > /proc/sys/net/ipv4/ip_local_port_range
>>
>> from that time on all iptables errors in the syslog were gone. the proxy
>> box is a dual opteron, 0.25 uptime.
>>
>
> It is possible that either your proxy and/or your servers encounter a
> duplex mismatch between their NIC and the switch. This is a very common
> problem. Run ethtool on your server to check that the link is correctly
> reported as Full Duplex. If the switch is forced to 100Full with a gigabit
> NIC in the server set to auto, you generally end up with 100 Half on the
> server. That alone could explain all what you are observing.
>
>
>> by the way: which timeout values uses haproxy for the httpchk option?
>>
>
> Since only one check can be running at a time on a server, the "inter"
> parameter serves both for the check interval and the check timeout.
>
> If you increase it above 3 seconds and you notice an important drop in
> the number of check failures, it would most likely indicate a network
> problem causing retransmissions to happen.
>
> Regards,
> Willy

Thank's for the information. I grabbed ethtool, the output looks good:

Settings for eth0:

        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: umbg
        Wake-on: g
        Current message level: 0x00000007 (7)
        Link detected: yes

ifconfig does not show any errors or overflows.

is there a way to tell haproxy to output a detailed report on failed requests?

changing inter from 1000 to 5000 did not really change anything. I now put it back to 1000 and upgraded the kernel, maybe (hopefully) it was a kernel bug. i'll keep the list informed.

regards,
corin Received on 2007/12/05 09:25