dns load balancing.

[edzy55]

Hi all

Can anyone advise on a working alternative to round robin dns for a load balancing solution. We currently have 2 citrix servers at 2 different locations which we want to load balance somehow from outside. Due to windows caching round robin this isn't a viable working option if one fails. I did think about keeping round robin and possibly reducing the ttl on the records to something really low. Is this a bad idea, will the cach ignore the ttl on the record or is their a better way to do this without breaking the bank?.

Hope this makes sense,

Edzy55

 

[kbing]

Depending on the Citrix version this may be called differently, but you can setup an Access Gateway web service to provide a Webportal for Citrix users. The web portal will use the inherent load balancing capabilities that Citrix has and do this automatically.

That way you have a central portal for all users...which can utilize both citrix systems.

Older versions of Citrix called this NFuse.

 

[edzy55]

KBing

Thanks for the response. We already have the secure gateway products that load balance;s the citrix servers internally for us. However, we want a load balancing or fail over solution from outside to the 2 public ip address's we have.

Thanks for your help.

Edzy55

 

[anawrocki]

See my post on a very simalar question. It is a possible way to make round robin work out with a short TTL. Other options exist but require $$$.

http://www.tek-tips.com/viewthread.cfm?qid=1300104&page=1

 

[edzy55]

Anawrocki,

Excellent, I love the ns server at each location idea though. That would still have the ttl problem if someone had connected recently though would it? We'll try to reduce the ttl first I think. Our domains are handled with an isp name servers so will have to approach them if possible to reduce. I know this will make their ns servers a bit more queryed but if the ttl expires when say someones connected via citrix what will happen then? Will their session be ok when it renews it?

Thanks again,

Edzy55

 

[anawrocki]

Not sure exacly what you are getting at, however, if the TTL is expired it will need to requery. Of course if you than get bounced to the wrong server your session is toast. This solution is based more along the lines of redundant paths to a single location.

Could you not use the Access Gateway to manage this? I am not a Citrix guy so you will have to forgive my ignorance there.

 

[anawrocki]

Not sure exacly what you are getting at, however, if the TTL is expired it will need to requery. Of course if you than get bounced to the wrong server your session is toast. This solution is based more along the lines of redundant paths to a single location. Your ISP may not want to go with a super short TTL, however if you host your own DNS there is nothing they can do to stop you from doing so.

Could you not use the Access Gateway to manage this? I am not a Citrix guy so you will have to forgive my ignorance there.