Balancing multiple Horizon Workspace gateway-va with HAProxy

When working with Horizon Workspace the first component you will scale to multiple instances is probably the gateway-va since this is the access point of all users, just to make sure it’s always available for connections.

In this case you need a load balancer to direct all users to all the gateway-va you have in your environment; i wrote about commercial and open source load balancers and also how to build one with HAProxy in this post.

I’m going to show you how i configure it with Horizon Workspace but remember that since I’ve learned about HAProxy only relatively recently by Luca Dell’Oca my configuration is just the way i do it and not necessarily the best so use the comments if you want to contribute.

#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------

global
log 127.0.0.1 local2 info
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
stats socket /var/lib/haproxy/stats

#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
option accept-invalid-http-request
retries 3
timeout http-request 60s
timeout queue 30m
timeout connect 1800s
timeout client 30m
timeout server 30m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
listen stats :9000
stats realm Haproxy\ Statistics
stats uri /stats

#---------------------------------------------------------------------
# Redirect to secured
#---------------------------------------------------------------------
frontend unsecured
bind :80
redirect scheme https if !{ ssl_fc }

#---------------------------------------------------------------------
# frontend secured
#---------------------------------------------------------------------
frontend front
bind :443 ssl crt /etc/haproxy/reverseproxy.pem
mode http

acl workspace hdr_beg(host) -i workspace.myvirtualife.net
use_backend workspace if workspace

#---------------------------------------------------------------------
# balancing between the various backends
#---------------------------------------------------------------------
backend workspace
mode http
server workspace1 192.168.110.10:443 weight 1 check port 443 inter 2000 rise 2 fall 5 ssl
server workspace2 192.168.110.11:443 weight 1 check port 443 inter 2000 rise 2 fall 5 ssl

Try to add a gateway-va and experiment with HAProxy to test HAProxy as load balancer. You can use this article if you want to know how to do it.

There are few more things worth of noting:

• timeouts are really long here otherwise users will experience disconnects because this is the kind of web app you keep open quite a lot;
• on port 9000 on the HAProxy host you will find statistics, for example “lb.yourcompany.yourdomain:9000/stats”, that will give numbers about state of connections and state of backends, problems, etc…
• “log 127.0.0.1 local2 info” is necessary if you want logging enabled which is so important when troubleshooting problems; a lot on how to read logs in the HAProxy documentation

if you intend to put a SSL cert like in my configuration, know that it has to be a chain of cert and private key like this:

-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
-----BEGIN RSA PRIVATE KEY-----
-----END RSA PRIVATE KEY-----

To make logging work and write to a separate file instead of putting everything in “/var/log/messages”, edit your “/etc/rsyslog.conf” file and make sure these lines are present:

# Provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

# HAProxy
local2.* /var/log/haproxy.log