Hi Willy,
i'll attach one session out of the logfile that goes wrong. As the session
begins, the first request has NI as cookie state which is logical because
it's a new session. Then you see some activity during the session where
the cookie state has VN as value. The last entry the cookie state all of a
sudden is NI and the backend changes to a different server.
What could be the cause of the NI during a session ?
the full haproxy config is :
global
log 127.0.0.1 local0
log 127.0.0.1 local1 notice
#log loghost local0 info
maxconn 128000
#debug
#quiet
user haproxy
group haproxy
defaults
log global
mode http
option httplog
option dontlognull
retries 3
option redispatch
hash-type consistent
maxconn 100000
timeout connect 36000
timeout client 300000
timeout server 300000
frontend http_proxy
bind 10.130.101.101:80
acl is_forms url_sub forms
use_backend weblogic-forms if is_forms
default_backend weblogic-overig
backend weblogic-forms
mode http
stats enable
balance roundrobin
cookie SERVERID insert indirect nocache
option http-server-close
option forwardfor
option httpchk HEAD /check.txt HTTP/1.0
server ias01n 10.130.101.5:80 check cookie ias01 weight 50
server ias02n 10.130.101.6:80 check cookie ias02 weight 50
server ias05n 10.130.101.1:80 check cookie ias05 weight 30
backend weblogic-overig
mode http
stats enable
balance roundrobin
cookie SERVERID insert indirect nocache
option http-server-close
option forwardfor
option httpchk HEAD /check.txt HTTP/1.0
server ias01n 10.130.101.5:80 check cookie ias01 weight 30
server ias02n 10.130.101.6:80 check cookie ias02 weight 30
server ias05n 10.130.101.1:80 check cookie ias05 weight 30
thank you
Yves
On Thu, Sep 17, 2015 at 3:03 PM, Willy Tarreau <[email protected]> wrote:
> Hi Yves,
>
> On Thu, Sep 17, 2015 at 02:12:23PM +0200, Yves Van Wert wrote:
> > Hi Willy,
> >
> > thank you for your quick response.
> >
> > I've changed the parameter but this didn't make any difference. I still
> > see a few connections changing backend servers without me being able to
> > explain this. Do you have any other pointers as to where i can look ?
> >
> > New config :
> > backend weblogic-forms
> > mode http
> > balance roundrobin
> > cookie SERVERID insert indirect nocache
> > option http-server-close
> > option forwardfor
> > option httpchk HEAD /check.txt HTTP/1.0
> > option log-health-checks
> > stats enable
> > stats auth admin:axihaproxy
> > server ias03 10.64.0.81:8888 cookie ias03 check inter 3000
> rise 5
> > fall 6 weight 40
> > server ias04 10.64.0.82:8888 cookie ias04 check inter 3000
> rise 5
> > fall 6 weight 10
> > server ias05 10.64.0.181:8888 cookie ias05 check inter 3000
> rise 5
> > fall 6 weight 40
> > server ias06 10.64.0.182:8888 cookie ias06 check inter 3000
> rise 5
> > fall 6 weight 10
>
> At this point your logs will be needed. Here are the possibilities :
>
> - the client forgets to send the cookie and is redistributed
>
> - a server occasionally fails to accept the connection and after a few
> retries, the connection is sent to another one (when "option
> redispatch"
> is present)
>
> - a server occasionally does a down/up cycle and its requests are
> redistributed but I think you said this didn't happen.
>
> The logs will indicate what's happening when you see the request being
> sent to the wrong server : the cookie flags will tell you whether an
> invalid, absent, valid cookie was present and if it targetted a down or
> an up server.
>
> Just out of curiosity, would you happen to have another backend behind the
> same frontend, on the same domain name, with the same cookie names ? It
> would be possible that some users switch from the two sites and retrieve
> another backend's cookie. For example, let's say you have 4 servers in this
> farm named ia03 to ia06, and another farm has only 3 servers named ia03 to
> ia05. Visitors of your first farm getting cookie ia06 will then go to the
> second farm with this cookie which will be invalid, be assigned a new one
> and when they come back to the first farm, they'll go to the server matched
> by this cookie.
>
> Hoping this helps,
> Willy
>
>
