Citrix NetScaler GSLB Management with Octoblu and NITRO

When using Citrix NetScaler to present a web accessible service using GSLB the NetScaler and GSLB has the ability to automatically fail over between sites and return the public IP Address of the currently live service.  This is great and a massive plus for any deployment, however, what if the internet connection goes down at a specific site but the NetScaler services are still up.  This will give the user the IP Address of the live service but they will not be able to connect to it as there is no inbound connection.

This post will show you how to use Citrix Octoblu to monitor those site connections and if required force a NetScaler service to be put into a down state and therefore fail the service over to the currently live site.  I know that you can do this with additional monitors on the GSLB service polling the sites upstream router, but lets face it, using Octoblu gives you more alerting capability and, and the most important, its damn cool !

So, lets get going.  First I will describe what I have in play here to mimic the scenario.

• Site A – Primary DC
• Site B – Fail Over DC
• vServer Site A – 192.168.0.230 – Port 1234 (I don’t have multiple external IP Addresses so use ports to separate traffic)
• vServer Site B – 192.168.0.231 – Port 5678 (I don’t have multiple external IP Addresses so use ports to separate traffic)
• gslboctoblu.bretty.me.uk – GSLB Domain Name (Site A Primary, Site B Failover)
• Firewall Rule Port 1234 –> vServer Site A
• Firewall Rule Port 5678 –> vServer Site B

Read the entire article here, Citrix NetScaler GSLB Management with Octoblu and NITRO

via Dave Brett at bretty.me.uk