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Malcolm,
If there is a conflict with performing both steps (iptables redirect and
binding the VIP to lo:0) then I would think this should have failed when
I first set it up. And now one real server is handling requests passing
responses to the client, while the other four have sessions in SYN_RECV
state. For example:
Every 5.0s: netstat
-t Fri Feb 28
22:15:42 2014
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign
Address State
tcp 0 0 172.18.30.20:http
<client_IP_address>:50864 SYN_RECV
I tried the two approaches you indicated on one of the failing servers
and got the same SYN_RECV result.
My servers are headless. No local browsers.
Thanks for the response and the ideas. I keep trying.
Bruce
On 2/28/14 3:23 PM, Malcolm Turnbull wrote:
> Bruce,
>
> You definitely only need one, and personally I find the iptables method
> easiest.
> NB. Your apache instance must be configured to respond to the VIP as
> well as the RIP (heath checks are on the RIP)
> If you use a local web browser on the real server does it work when
> you connect to the VIP ? i.e.
>
> links x.x.x.x
>
> IF so then great but your routing is probably messed up by the lo:0 adapter.
>
>
>
>
>
>
> On 28 February 2014 20:01, Bruce Rudolph <brudolph@xxxxxxxxxxx> wrote:
>> I followed instructions from two sources
>>
>> 1)
>> http://www.centos.org/docs/5/html/Virtual_Server_Administration/s2-lvs-direct-iptables-VSA.html
>>
>> I updated iptables using the commands on this page.
>>
>> 2)
>> http://ptylr.com/2013/05/01/configuring-lvs-piranha-on-centos-for-direct-routing/
>>
>> This page had information on configuring lo:0 which was
>> the final step that I needed to get LVS-DR to work.
>>
>> The setup this way had been working since last August. It is still
>> working on one of the real servers but not on four other ones. Very odd.
>>
>>
>>
>> On 2/28/14 2:26 PM, Malcolm Turnbull wrote:
>>> snip -- "I have setup
>>> LVS-DR using IPTables."
>>>
>>> Then why are you using a loopback adapter as well?
>>>
>>> You only need to use one method iptables REDIRECT .... or ...
>>> loopbackadapter + arptables settings
>>>
>>> SYN_RECV means the real server is not replying when hit with a packet
>>> that says Hi are you the VIP?
>>>
>>>
>>>
>>> On 28 February 2014 19:21, Bruce Rudolph <brudolph@xxxxxxxxxxx> wrote:
>>>> I have an LVS-DR cluster which has been running for seven months without
>>>> a hitch. Recently, the cluster started to timeout on the majority of
>>>> connections. Some connections were passed through to a real server and
>>>> processed. I have tried for a week to figure out what happened. What I
>>>> found was that one real server out of five is connecting and servicing
>>>> the client request. The other four real servers have the HTTP connection
>>>> stuck in the SYN_RECV state until it times out (60 seconds).
>>>>
>>>> In summary, I have seven CentOS 6.4 servers (kernel
>>>> 2.6.32-358.18.1.el6.x86_64). Two servers are configured as load
>>>> balancers (a primary and a backup) and five real servers. I have setup
>>>> LVS-DR using IPTables. The servers have a public IP bound to a NIC
>>>> device and an internal VLAN bound to a second NIC. The VIP is configured
>>>> on the real servers local loopback (lo:0) device. The
>>>> /etc/sysconfig/ha/lvs.cf was setup properly and everything was running
>>>> successfully for seven months.
>>>>
>>>> We installed new versions of our software for the web service we are
>>>> running. Nothing network related. All five real servers were updated the
>>>> same way. I am comparing the one working real server from the four that
>>>> are not working. So far I have found nothing.
>>>>
>>>> Any ideas on trouble shooting points?
>>>>
>>>> --
>>>> Best Regards,
>>>> Bruce
>>>>
>>>>
>>>> _______________________________________________
>>>> Please read the documentation before posting - it's available at:
>>>> http://www.linuxvirtualserver.org/
>>>>
>>>> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
>>>> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
>>>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>>>
>> _______________________________________________
>> Please read the documentation before posting - it's available at:
>> http://www.linuxvirtualserver.org/
>>
>> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
>> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>
>
_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/
LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
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