How to create a feedback page for Load Balancers in the VISULOX GATEWAY configuration

In installations with Load Balancer and multiple VISULOX GATEWAYS, the Load Balancer is probing the vitality of the VISULOX GATEWAYS by accessing port 443.

During maintenance the VISULOX GATEWAY could have 443, but should be removed from the load balancing policy.

Therefore an extra probing is needed with a special response from the VISULOX GATEWAYS: VISULOX GATEWAY can be used for production (ON), VISULOX GATEWAY from probing (OFF).

After setup of the VISULOX Gateway, the load balancer probing template file is available.

This article explains how to configure special answer pages on the VISULOX GATEWAY

Create feedback page

CODE

echo "<html><head> </head><body> Gateway is on </head></html>" > /opt/SUNWsgdg/httpd/httpd-default/htdocs/lb_endpoint.html

Add extra webserver in /opt/SUNWsgdg/httpd/httpd-default/conf/extra/gateway/http-gateway.conf

CODE

ProxyPass /lb_endpoint.html !

Restart VISULOX GATEWAY webserver

Restart Apache in VISULOX GATEWAY

BASH

GWPATH=/opt/SUNWsgdg
APACHEPATH=$GWPATH/httpd/httpd-$(cat /opt/SUNWsgdg/var/info/apacheversion)
$APACHEPATH/bin/apachectl -k restart -d $APACHEPATH -D SSL

Testing from Load Balancer

URL to check availability of feedback name from the Load Balancer

https://<gateway/lb_endpoint.html

To disable the VISULOX GATEWAY rename lb_endpoint.html to OFF-lb_endpoint.html.

The feedback name can be any name which is found in the documentroot.

If the feedback name is not available (because of renaming), the client, which is the Load Balancer gets as the error code 404. This has to tell the Load Balancer to remove this VISULOX GATEWAY temporarily until the name is available again.