Forum Discussion

Matt_Breedlove_'s avatar
Matt_Breedlove_
Icon for Nimbostratus rankNimbostratus
Jun 07, 2009

Remote LTM pooling or connection deflection

Is it possible to have a client come in to LTM A with www.website.com and have LTM A remotely "pool" or deflect the connection to a vs and/or pool on LTM B without a redirect or additional client roundtrip...as well as change the hostname sent back to clients browser after initial page load?

 

So when client comes in initially they request www.website.com and LTM A takes the connection at VS/Irule level.

 

LTM A then transparently passes same initial connection to a vs/pool of servers on LTM B to actually service the request.

 

LTM A would make routing decisions based on HTTP cookie (which is why GTM doesn't work for this)

 

To the end user the experience would be:

 

-Open Browser - First request "www.website.com"

 

-Page loads once with content and hostname in address bar is now "new.website.com" (content came

 

from LTM B)

 

-Second client request automatically goes directly to "new.website.com" (which is VS on LTM B...so now LTM A is out of picture and will remain out of picture)

 

If this is possible, it may be useful in distributing load among three of our LTM clusters. Each cluster is 2 bigip's in HA mode. 1 is running at 50% utilization, while other two are less.

 

We are looking at ways to distribute this load and risk more equally, among our LTMs, without penalizing clients with extra roundtrips or requiring that they change the hostnames they use to access us

 

Thanks
application delivery
dev
devops
iRules
  • Juerg_Wiesmann's avatar
    Juerg_Wiesmann
    Icon for Nimbostratus rankNimbostratus
    Jun 08, 2009
    Hi Matt,

     

    The simple answer is, if I understood you right, no

     

    If you terminate a session on a VS on LTM-1 Client will always connect to this virtual, since DNS is resoving to this address allways.

     

    If you would send a redirect to the client the new connection could then end up on a Virtual based on LTM-2,LTM3 aso. This is not very sexy, since you could not weight availability, GeoLocation or usage.

     

    GTM would help here, and would also be able to answer DNS requests from the same DNS Resolver allways with the same VS IP Adress (VS on BIG-IP-1, or VS on BIG-IP-2 aso.)

     

    All of this virtuals would then be able to handle several Pool Members and Cookies of Cookie Persistence are honored at that point.

     

    In my opinion a pair of BIG-IP's should be able to handle all requests you need. Just make sure to account the number of Requests expected overall.

     

     

    Kind Regards

     

     

    wiesmann