IRule Creation help

You could look in the BIG-IP stats information in the GUI and show that each of the pools is receiving a given amount of traffic. Or you could build any kind of custom reporting you want with a stats profile or snmp info or the like.

 

 

Colin

So I assume that cookie insert persistence will not work with this irule. Would this still work if the irule directed to virtual servers (rather than pools ) and then apply a persistence profile to each vs?

 

 

Thanks,

 

 

Martin

Interesting, the problem is once you introduce persistence you have more of a chance of not distributing the traffic as planned..

 

 

I remember reading about a similar issue earlier in the year... Here is the post dug up.

 

 

http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/1176748/showtab/groupforums/Default.aspx

 

 

Read through the post, you could try enabling a persistence profile and using "match across".. but I'm not sure that is going to work for you and your cookie persistence requirements..

 

 

Also, the post makes reference to "ratio" load balancing.. Could you possibly use one pool and use Ratio for a LB metric?

 

 

Otherwise you could probably go at it a few ways.. One idea, what if you set a unique cookie for each pool during the random logic, then before the random logic you could check if either cookie exists and send it to the appropriate pool..If no cookie, then you start the random logic. Problem is now we would need to figure out how to take the existing persistent traffic into your % metric or you're not going to be meeting your original goals..

 

What do you want the user persisted to? Do you want to ensure that once they go to poolA they always go to pool A? If so you could use your own cookie to do this:

when HTTP_REQUEST {
    Check if there is a pool selector cookie in the request
    Use a switch statement to ensure only valid pool names are present
    instead of accepting any pool name from the user supplied cookie
   switch [HTTP::cookie pool_cookie] {
      poolA -
      poolB -
      poolC {
          Select the pool from the cookie
         pool [HTTP::cookie pool_cookie]
         set selected ""
      }
      default {
          No pool selector cookie, so randomaly choose a pool
          Save a random number between 0 and 1
         set rand [expr { rand() }]
         if { $rand < .90 } { 
            pool poolA
            set selected poolA
         } elseif { $rand < .95 }{
            pool poolB
            set selected poolB
         } else {
            pool poolC
            set selected poolC
         }
      }
   }
}
when HTTP_RESPONSE {
    Set a pool selector cookie if a pool was selected for this request
   if {$selected ne ""}{
      HTTP::cookie insert name pool_cookie value $selected path "/"
   }
}

If you need persistence within the pool members you could use a default cookie insert persistence profile. This will "just work" even when using multiple pools on the same virtual server.

Aaron

Hello,

 

Is it possible once I implement the below iRule(25% percent of production web traffic being routed to staging_web pool) on our production web virtual server to then route all traffic from the staging_web pool to our staging_app pool of servers via the production app virtual server? The dev team does not want to change DNS entries once we do a deploy to staging then production. Could I apply an iRule on the production app virtual server routing any traffic from the staging web servers to the staging_app pool?

 

when HTTP_REQUEST { if { rand() > 0.25 } { pool default-pool } else { staging_web } }

 

Thank you,