Forum Discussion

Mike_Mergens_61's avatar
Mike_Mergens_61
Icon for Nimbostratus rankNimbostratus
Oct 22, 2013

iRule for Global redirect and failiover

I have an application that is located in three data centers. The DC's are located in the US and Europe. I have two GTM's located in the US DC's. I would like to have users from Europe directed to the Europe DC and US Users directed to the US DC in round robin. Should the Europe DC become unavailable I would than like users to be directed to the US DC's. I believe this can be done with an iRule but not sure where to start.

 

At some point I will have an instance of the application in Asia and would like to direct those users to the Asia DC.

 

Mike

 

application delivery
availability
devops
iRules

4 Replies

Sort By
  • Mike_Mergens_61's avatar
    Mike_Mergens_61
    Icon for Nimbostratus rankNimbostratus
    Oct 22, 2013

    Mohamed,

     

    I'm attemoptign to setup on the GTM's. I tried global availabiliy and Topology settings. Seems that it is doing round robin only. I see Europe connectons in the US DC's and US in Europe. I read someware that I needed a ldns (?) running at each loaction. I only have GTM's in the US datacenters taht can gather Statistics.

     

    Mike

     

    • Mohamed_Lrhazi's avatar
      Mohamed_Lrhazi
      Icon for Altocumulus rankAltocumulus
      Oct 22, 2013
      LDNS just means local DNS server, and so in GTM context, that simply means the client. If the client IP is in the US, use US data center....etc. Now, you are right, the fact that your European DC does not have GTM makes it sound a bit odd... but should not really be a problem I think. Do you have LTM in Europe? How is GTM configured? one wide_ip? and how many pools? what's in each pool? three data center objects?.... Some combination of all these confguration objects should provide what you need...
  • Matt_Dierick's avatar
    Matt_Dierick
    Icon for Employee rankEmployee
    Oct 22, 2013

    The solution is Topology. As Mohamed says, Local DNS is the client. So the client IP address is the local DNS IP address.

     

    Topology will allow you to specify :

     

    • All Europe users to Europe DC --> till DC goes down
    • All US users to US DC --> till DC goes down

    You just need to set a topology policy and assign it to your load balancing method.

     

    Be careful, Topology can be apply on WideIP and Pool. Assign it the right context.