IRule Creation help

I'm sure that some other folks will have ideas here too, but this particular issue is a little hard to solve directly. After all, how much of your traffic is 2%? You won't really know what 2% was until your day is done and you're counting requests in your server logs. But you can approximate it using something like below.

**Note: This uses the (totally great) table command, which requires 10.1 or higher. Also, this rule is an example only and it may not work for your requirements. That said, it will send 2% of HTTP requests to a specific place.

when HTTP_REQUEST {

    set requestNum [table incr "mkt_count" ]

    if { $requestNum >= 99 }{
        table set "mkt_count" 0
    }

    if { $requestNum == 1 or $requestNum == 2 } {
        log local0. "Got a 2% request. Counter is at $requestNum"
        pool marketing-pool
    } else {
       log local0. "Got a normal request. Counter is at $requestNum "
        pool default-pool
        }
}

Give this a whirl in your test environment and see if it will work for you. Obviously, change your pool names to match. Also, if any of the smart folks out there have ideas to bulletproof this approach please chime in! This is a very cool use case.

HTH,

-Matt

Hi Ido,

 

incidentally you can find information about the table command here

 

 

http://devcentral.f5.com/wiki/default.aspx/iRules/table.html

 

 

I hope this helps

 

Bhattman

Thanks a lot, I will try it on our test env.

 

 

Ido

when HTTP_REQUEST { 
  if { rand() > 0.02 } { 
    pool default-pool 
  } else { 
    pool marketing-pool 
  } 
} 

Regards

Kevin

Hi Guys,

 

 

I have a similar requirement from my marketing team but they would like to send 90% of traffice to a default pool and then 5% to pool x and 5% to pool y . Is this achievable?

 

 

Thanks,

 

 

Martin

Sure, you could use effectively the same logic as above just move some numbers around. Send anything that's 1-5 to poolA, 6-10 to poolB, and the rest to the main pool.

 

 

Colin

If you have any issues or questions, feel free to ask and I'm happy to help with the code.

 

 

Colin

Hi Colin,

 

 

How could I set the range from 1-5 for example using $requestNum or is there something I could do using the rand command above?

 

 

Thanks,

 

 

Martin

Hi Martin,

I think this is what Colin was suggesting:

when HTTP_REQUEST {
   Save a random number between 0 and 1
  set rand [expr { rand() }]

  if { $rand < .90 } { 
    pool poolA
  } elseif { $rand < .95 }{
    pool poolB
  } else {
    pool poolC
  }
}

Aaron

Thanks Aaron this seems to work well. How could I prove (to marketing) that the pools are being load balanced as requested. Do I need to create a stats profile?

 

 

Thanks,

 

 

Martin