Netscaler Load Balancing XML and STA's, in the Citrix Web Interface forum on BrianMadden.com

There are a few doc’s that are posted on Citrix’s Support site stating that “when” using the AGEE for ICA Proxy, you should use the Netscaler to load balance the XML services and the STA’s by creating an XML virtual server and pointing your STA’s and XML services at this Virtual server.

I’ve tested this configuration in a lab and at multiple offices and have been quite un-successful.

The problem is that “when load balanced”, the STA ID’s will constantly change. If the Web Interface and the Access Gateway receive different STA ID’s, the ICA connection will fail. Web Interface and Access Gateway Enterprise have their own load balancing method for the XML and STA servers. This is done by listing the same STA servers on the AGEE Vserver as you list in the Web interface.

Anyone else run into this issue?

Same problem here... did you, or someone else here, find a solution to this?

I've been running load balancing active - active site congfiguration between two data centers using the V-Servers for XML and Web Interface. 

 

Configuration on netscaler is two Vservers one that contains Seervices that monitor XML and the second that monitors WI.  An individual service for each farm instance of Web Interface and XML broker.  XML monitor with interval of 5 seconds, response time-out of 5, down time of 30 4 retries and port 80 monitoring Notepad application that is published on each PS server.WI monitor with site path to the default.aspx interval of 5 seconds, response timeout 2, down time 30 and 3 retries.  Within web interface the xml broker points to the ip of the vserver. 

In GSLB we created an vserver for the site selecting method and persistence method Choose method Least Connection, Dynamic Weight disabled,  Persistence sourceIP, persistence mask 255.255.0.0 timeout 200 minutes and persistence ID 1.  This vserver manages services for each Netscaler HA pair where we are monitoring pings to the netscaler device, site wi and site xml servers.

Hope this gets you closer.

Best wishes

JLH

thanks, I will look into this.

The web interface does not care on what STA server will give him his ticket. So loadbalancing multiple STA thru the netscaler is no issue.

Yet, when the user tries to start his application. the STA's identifier is given to the CAG (netscaler)... The CAG needs to know where this server is at and checks this server if the given ticket is valid.

Conclusion; the Access gateway Virtual server needs seperate references to all STA's. You can't refer here to a load balanced VServer...

The Webinterface can use the loadbalanced VServer for it's STA, but all possible STA servers within the loadbalanced cluster need to be entered in the Access Gateway VServer as well.

To further explain Roels response.

You CAN NOT load balance STAs.  If you create a STA vserver and apply it to your access gateway it will be confused and show no identifier and the state will  be down.

This is on  NS 9.0 rev 66.12 with the CAG/AAC function rolled into the AGEE.

Working on the GSLB aspect of it now.

Remember that each STA keeps track of its own tickets.  So, if a user tries to launch a session by passing a ticket it got from STA1 to STA2, STA2 will know nothing about it and will reject the request.  So, no, you can't load balance STAs. XML servers should work.

Hi,

I have tested this scenerio; load balancing XML and WI successfully.

The STA's can be load balanced as a virtual server and configured on the WI server's...however on the Access Gateway individual STA server names must be specified, otherwise the ticket is rejected; reason explained above.

Thanks

Andrew