Exchange 2016,outlook not updating inbox but connected


#1

Hi,
i have setup an exchange 2016 site (three exchange mbx), in front of site one squid3 as ssl offloading.
I did try to focus squid on MBX1 first , then MBX2 and 3, all work as expected.
Now I made a haproxy server to insert between squid and my mbx’s. Squid make ssl offload and focus on haproxy,
this distribute load on 3 mbx.
All works as expected, but sometimes (more often under load), outlook he says it is connected, but inbox
not updating. I can send email, but my inbox do not update until i restart Outlook or i tell to squid to focus on one mbx instead haproxy.
Request are made only with rpc over http, no mapi for now…
My haproxy is 1.5.8, same problem with 1.6
Any tips?
Thanks

global
log /dev/log local0 notice

    chroot /var/lib/haproxy
    stats socket /run/haproxy/admin.sock mode 660 level admin
    stats timeout 30s
    daemon

defaults
log global
mode http
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http

    stats enable
    stats uri /stats
    stats realm Haproxy\ Statistics
    stats auth admin:XXXXXX
    maxconn 100000

option http-keep-alive
option prefer-last-server
no option httpclose
no option http-server-close
no option forceclose
no option http-tunnel
log global
option httplog
option forwardfor
balance leastconn
default-server inter 3s rise 2 fall 3
timeout client 600s
timeout http-request 10s
timeout connect 10s
timeout server 60s

############################################################################################################
################################################### HTTP ###################################################
############################################################################################################

frontend fe_ex
mode http
bind 172.30.1.201:80

acl autodiscover url_beg /Autodiscover
acl ecp url_beg /ecp
acl ews url_beg /EWS
acl mapi url_beg /mapi
acl eas url_beg /Microsoft-Server-ActiveSync
acl oab url_beg /OAB
acl owa url_beg /owa
acl rpc url_beg /rpc

use_backend be_ex_autodiscover if autodiscover
use_backend be_ex_ecp if ecp
use_backend be_ex_ews if ews
use_backend be_ex_mapi if mapi
use_backend be_ex_eas if eas
use_backend be_ex_oab if oab
use_backend be_ex_owa if owa
use_backend be_ex_rpc if rpc
default_backend be_ex

backend be_ex_autodiscover
mode http
balance roundrobin
option httpchk GET /autodiscover/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_ecp
mode http
balance roundrobin
option httpchk GET /ecp/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_ews
mode http
balance roundrobin
option httpchk GET /ews/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_mapi
mode http
balance roundrobin
option httpchk GET /mapi/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_eas
mode http
balance roundrobin
option httpchk GET /microsoft-server-activesync/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_oab
mode http
balance roundrobin
option httpchk GET /oab/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_owa
mode http
balance roundrobin
option httpchk GET /owa/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex_rpc
mode http
balance roundrobin
option httpchk GET /rpc/healthcheck.htm
option log-health-checks
http-check expect status 200
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none

backend be_ex
mode http
balance roundrobin
server srv-mbx1 172.30.1.203:80 check inter 15s verify none
server srv-mbx2 172.30.1.204:80 check inter 15s verify none
server srv-mbx3 172.30.1.205:80 check inter 15s verify none