Load Balancer

For proper clustering of the Flowable Server requests coming from a browser a load balancer is needed. The load balancer has to support either WebSockets or sticky sessions (if long polling is used). In this example we will setup NGINX.

  1. Download NGINX from the NGINX Website at http://nginx.org/en/download.html (only for Windows, use either Homebrew for macOS, the packaging manager of your Linux distribution or even a Docker image).

  2. Add the following configuration to the nqinx.conf file lying in the conf directory of NGINX:

http {
    upstream backend {
        # nginx can use the client's source ip for load balancing
        ip_hash;
        server flowable01:8090; #hostname/IPs of the Flowable Server nodes
        server flowable02:8090;
    }

    server {
        listen 80;
        location / {
            proxy_pass http://backend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            # enables WS support
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }
    }
}