# HAProxy loadbalancing for SOAP interface
**URL:** https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577
**Category:** Help!
**Created:** [August 18, 2016, 4:56pm UTC](https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577 "2016-08-18T16:56:38Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@fzhang](https://discourse.haproxy.org/u/fzhang)
#### Post date: [August 18, 2016, 4:56pm UTC](https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577/1 "2016-08-18T16:56:38Z")
Hello everyone,
I try to using HAproxy do the Load balancing for SOAP interface, the haproxy configuration like this:
```
frontend ft_DMC_L7_HTTP_50403
bind haproxy-lh:50403
mode http
log global
option httplog
timeout client 900s
maxconn 2000
acl allowed_dmc_uris url_reg -i ^/(dmc)
acl allowed_ADDWeb_uris url_reg -i ^/(ADDWeb/)
http-request deny unless allowed_dmc_uris or allowed_ADDWeb_uris
use_backend bk_DMC_L7_HTTP_50403_ADDWeb if allowed_ADDWeb_uris
default_backend bk_DMC_L7_HTTP_50403
backend bk_DMC_L7_HTTP_50403
balance roundrobin
mode http
log global
option httplog
option forwardfor except 127.0.0.1/8
cookie JSESSIONID prefix nocache
default-server inter 3s rise 2 fall 3 slowstart 0
option httpchk HEAD / HTTP/1.0 # Advanced http check
timeout server 120s # Server inactivity timeout
server SRV01 SRV01:50400 maxconn 2000 weight 10 cookie E1 check
server SRV02 SRV02:50400 maxconn 2000 weight 10 cookie E2 check
backend bk_DMC_L7_HTTP_50403_ADDWeb
balance roundrobin
mode http
log global
option httplog
timeout server 25s
timeout connect 10s
server SRV01 SRV01:50400 maxconn 2000 weight 10 check
server SRV02 SRV02:50400 maxconn 2000 weight 10 check
```
But the result is client didn’t get soap response, tcpdump capture display “TCP ACKed unseen segment”.
6 0.622194 10.200.99.5 10.200.101.248 HTTP/XML 760 POST /ADDWeb/services/SetSubscriberDetails HTTP/1.1
7 0.659787 10.200.101.248 10.200.99.5 TCP 54 [TCP ACKed unseen segment] 50403→35061 [ACK] Seq=17652722 Ack=1129711 Win=7296 Len=0
8 1.136932 10.200.101.248 10.200.99.5 HTTP/XML 589 [TCP ACKed unseen segment] HTTP/1.1 200 OK
Kindly help me for this issue.
---
### Author:  [@lukastribus](https://discourse.haproxy.org/u/lukastribus)
#### Post date: [August 19, 2016, 8:27am UTC](https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577/2 "2016-08-19T08:27:31Z")
> [@fzhang](#):
>
> But the result is client didn’t get soap response, tcpdump capture display “TCP ACKed unseen segment”.
More importantly the tcpdump shows “HTTP/1.1 200 OK” which means a positive HTTP response is send towards the client. So there doesn’t seem to be any problem.
Will need full pcap captures to investigate further.
---
### Author:  [@fzhang](https://discourse.haproxy.org/u/fzhang)
#### Post date: [August 19, 2016, 9:01am UTC](https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577/3 "2016-08-19T09:01:02Z")
Hi Lukas,
Thanks for your reply,
I have uploaded soap.cap file in the [https://cloud.sicap.com/index.php/s/wq7UQAv1RvYDddK](https://cloud.sicap.com/index.php/s/wq7UQAv1RvYDddK)
Best Regards,
Frank
---
### Author:  [@lukastribus](https://discourse.haproxy.org/u/lukastribus)
#### Post date: [August 19, 2016, 9:24am UTC](https://discourse.haproxy.org/t/haproxy-loadbalancing-for-soap-interface/577/4 "2016-08-19T09:24:42Z")
Not sure what happens here. The answer is there, but it seems the TCP connection is messed up. Does the request actually fail on the application level? If yes, with a timeout?
How exactly did you take this capture? On the haproxy box, or on the client? Are there any TCP intercepting middleboxes between the client and the server?
Can you exclude a client problem?