David_Dalgaard_

Jul 12, 2012Nimbostratus

# iRule Performance

Hi folks

We are just starting to look into iRules and I am trying to figure out what performance impact iRules will have. I googled around and found the following thread:

https://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/3650/showtab/groupforums/Default.aspx

UnRuleY gives a great explanation, but this explanation falls apart when I try to use the iRule Runtime Calculator.

I have an iRule where average CPU cycles is 170000. The box it is deployed on is a 6900 (2 CPUs, 2 cores @ 2,2GHz). As far as I can understand iRules are fully compatible with CMP, which means that I could roughly multiply the clock by four, but just to make it simple let us calculate with 1 core only.

Average CPU cycles * executions per second / clock frequence = 170,000 * 100 / 2,200,000,000 = 0.007727 % (this number makes great sense to me, but I might have misunderstood something in regard to CPU cycles/clock frequence)

However, when I use the calculator and put 170000 under Event_1, I get the above results - but I don't think it's multiplied by 100.....

Can anyone tell me if unRuleY/I made a calculation error or is it the calculator that is wrong??

Thanks!