# HAproxy configuration for loadbalancing WUVC (Webconsole) between Tomcat servers

# HAproxy will 2 do things:
# 	1. Loadbalancing of Webconsole requests between 2 or more Tomcat servers
#	2. Provide one or more failover servers in case a Tomcat server crashes
# IMPORTANT: For HAproxy to work with WUVC it is important to have stickiness between the source (desktop that runs UVC) and the Tomcat server (see keywords "stick on src")
# Limitation: The loadbalancing is based on the IP address of the desktop, as a consequence all UVC Consoles started with the same IP (same desktop) will connect to the same Tomcat (see keyword "stick-table) 

# Tested with HA-Proxy version 1.5.4 2014/09/02
# Frontend (http-in) is listening on 8081 and forwarding requests to 2 backends (tomcat_servers) on 8080
# IMPORTANT: Modify the file <tomcat>/webapps/<univiewer_webconsole>/WEB-INF/conf/uvc.vm on each deployed WUVC by adding the *frontend* to the codebase variable, for instance:
# <jnlp spec="1.0+" codebase="http://vmst_frontend.orsyp.com:8081/univiewer_webconsole_6.x.yy_all_os" >

# Start HA Proxy with the following command:
# haproxy -f <path to this conf file>   -Vdb -p <path to file to write PID> 
# For instance: haproxy -f /apps/haproxy/haproxy.conf -Vdb -p /apps/haproxy/truc.log
    
	global
        daemon
        maxconn 256 # at least sum of all maxconn statements in the backend section below

    defaults
        mode http # tcp works as well but is a bit slower, but may be more reliable
        timeout connect 5000ms
        timeout client 50000ms
        timeout server 50000ms
		
#	To activate logging uncomment the 2 following lines in /etc/rsyslog.conf
#	#$ModLoad imudp
#	#$UDPServerRun 514
#	and ADD the 2 following lines to the same file:
#	local0.* -/var/log/haproxy_0.log
#	local1.* -/var/log/haproxy_1.log

	log global
	log 127.0.0.1:514 local0 # rsyslog has to be actiavted to use this, see logs in /var/log/haproxy_0.log

    frontend http-in
#	log 127.0.0.1:514 local0 debug # activate rsyslog, see /var/log/haproxy_0.log
        bind vmst_myfrontend.orsyp.com:8081
        default_backend tomcat_servers

    backend tomcat_servers
#	log 127.0.0.1:514 local1 debug # activate rsyslog, see /var/log/haproxy_1.log
#	balance leastconn # only leastconn (without forcing stickiness) fails during authentication on UVMS
#	balance roundrobin # only roundrobin (without forcing stickiness) fails with half of the requests (when using 2 backend servers)

#	<stick_table>, <stick on scr> with <roundrobin>|<leastconn>

	stick-table type ip size 1m expire 1h
	stick on src
	balance leastconn

        server tom1 vmst_backend_1.orsyp.com:8080 maxconn 128 check inter 60
        server tom2 vmst_backend_2.orsyp.com:8080 maxconn 128 check inter 60
#       server tom3 vmst_backend_3 ... add as many backends as needed

# Activate the HAproxy statistic page accessible on port 8082 of the haproxy server
# version, realm and auth can be activated for admins
# Stats on http://vmst_frontend.orsyp.com:8082/

   listen stats :8082
	mode http
	stats enable
	stats uri /
#	stats hide-version
#	stats realm Haproxy\ Statistics
#	stats auth Username:Password # login and password for stats page