Load Balancer Configuration

This section provides setup instructions for configuring a load balancer for Zephyr Enterprise Data Center. Any load balancer can be configured to work, however we recommend using NGINX. Below you will find a guide on setting up a NGINX load balancer with Zephyr Enterprise Data Center.

Before you begin

Review all system requirements thoroughly

Ngnix Setup on Windows

Step 1:
Download the Nginx archive file from here

Step 2:
In the conf folder, find the file named nginx.conf and modify the http section to contain the following:

Under the http { .. } section

upstream tomcat_servers{
	server node1:8080;
	server node2:8080;
}
location /flex/ {
	#for web socket and long-polling in nginx
	proxy_http_version 1.1;
	proxy_set_header Upgrade $http_upgrade;
	proxy_set_header Connection $connection_upgrade;
	proxy_buffering off;
	proxy_ignore_client_abort off;
	#for tomcat proxy
	proxy_set_header X-Forwarded-Host $host;
	proxy_set_header X-Forwarded-Server $host;
	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	proxy_set_header X-Real-IP $remote_addr;
	proxy_pass ;
}
location ~* \.(js|jpg|png|css)$ {
	root <path to webapps>;
	expires 1d;
	#proxy_set_header Host $http_host;
	#proxy_set_header X-Real-IP $remote_addr;
	#proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	#proxy_pass http://tomcat/;
}

Add a separate section within the http section:

Additional section

map $http_upgrade $connection_upgrade {
	default Upgrade;
	'' close;
}

Ngnix Setup on Linux

Step 1:

sudo apt-get install nginx

Step 2:
Edit /etc/nginx/nginx.conf or /etc/nginx/sites-available/default (if present) and add to the http section:

Under the http { .. } section

upstream tomcat_servers{
	server node1:8080;
	server node2:8080;
}
location /flex/ {
	#for web socket and long-polling in nginx
	proxy_http_version 1.1;
	proxy_set_header Upgrade $http_upgrade;
	proxy_set_header Connection $connection_upgrade;
	proxy_buffering off;
	proxy_ignore_client_abort off;
	#for tomcat proxy
	proxy_set_header X-Forwarded-Host $host;
	proxy_set_header X-Forwarded-Server $host;
	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	proxy_set_header X-Real-IP $remote_addr;
	proxy_pass ;
}
location ~* \.(js|jpg|png|css)$ {
	root <path to webapps>;
	expires 1d;
	#proxy_set_header Host $http_host;
	#proxy_set_header X-Real-IP $remote_addr;
	#proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	#proxy_pass http://tomcat/;
}

Add a separate section with the http section:

Additional section

map $http_upgrade $connection_upgrade {
	default Upgrade;
	'' close;
}

Sample Nginx.conf file:

Configure Nodes

Step 1:
In node1 locate the web.xml file (opt/local/zephyr/tomcat/webapps/flex/WEB-INF/web.xml)

Step 2:
Locate 'AtmosphereServlet' in the file and add the below mentioned lines as an additional 'init-param' tag:

Additiontal init-param

<init-param>
<param-name>org.atmosphere.cpr.AtmosphereInterceptor</param-name>
<param-value>org.atmosphere.interceptor.NginxInterceptor</param-value>
</init-param>

Sample web.xml file:

Step 3:
In web.xml (default path: opt/local/zephyr/tomcat/conf/web.xml) add the <distributable/> tag at the end of the file, before </web-app>

Sample web.xml file:

Step 4:
Follow steps 1-3 for node2

Step 5:
In the conf folder for NGINX, find the file named nginx.conf. Under upstream add both the IP addresses:

Upstream

upstream tomcat{ 
    ip_hash; 
    server 192.168.11.192:81; 
    server 192.168.11.98:81;  
}

Step 6:
Restart Nginx and launch Zephyr with the IP address of Nginx (e.g.: 192.168.11.153/flex). You will be redirected to any one of the configured Nodes