Forum Discussion

Mark_Stradling_'s avatar
Mark_Stradling_
Icon for Cirrus rankCirrus
Jul 01, 2010

Case Statement Efficiency

Hello,

 

 

I'm rewriting very messy iRules. Currently, they are all if / elseif statements which I am converting to switch statements. Upon going through the rule, I realized that a number of various statments send traffic to the same pool but they are split up. Would it be more efficient to group these together.

 

 

Current example:

 

conditions 1a, 1b, 1c

 

pools 1

 

 

case 1a then

 

pool 1

 

case 1b then

 

pool 1

 

case 1c then

 

pool 1

 

 

Would it be more efficient to do this:

 

 

case (regexp) 1a | 1b | 1c

 

pool 1

 

 

Thanks!
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  • The_Bhattman's avatar
    The_Bhattman
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2010
    Hi Mark,

     

    I think you would want to use the switch statement, which is similiar to case which is more efficient the the IF-ELSE statements.. Of course it would depend on what you are inspecting in the conditional statement.

     

     

     

    Bhattman
  • Michael_Yates's avatar
    Michael_Yates
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2010
    I agree with Bhattman, I would guess that a set of switch statements would be more efficient with a default action in case none of the switch statement conditions have been met.

    You can also send multiple switch statements to the same location: 

    
when HTTP_REQUEST {
switch -glob [string tolower[HTTP::uri]] {
"/content1*" -
"/content2*" { pool pool.for.content1and2 }
"/content3*" { pool pool.for.content3 }
default  { HTTP::redirect http://[getfield [HTTP::host] ":" 1]/content1 }
}
}
  • Mark_Stradling_'s avatar
    Mark_Stradling_
    Icon for Cirrus rankCirrus
    Jul 02, 2010
    "/content1*" -

     

    "/content2*" { pool pool.for.content1and2 }

     

     

    Perfect. This snippet above was what I was looking for. I'm trying to group requests that go to the same pool. I wasn't totally sure how to do it in TCL.

     

    Thanks,

     

    Mark