how to use switch to match datagroup

1

 

 

Data Group List use in a switch

 

http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/1179074/showtab/groupforums/Default.aspx

 

 

2

 

 

in your case, using [HTTP::path] is more efficent.

Hi,nitass

 

I have read one link to ask me to use variable if we need to evaluate it repetitively

 

 

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/281/Ten-Steps-to-iRules-Optimization.aspx

 

6- Use Variables

 

 

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/281/Ten-Steps-to-iRules-Optimization.aspx

 

6- Use Variables since you do nothing on [HTTP::path], i do not think using variable is more efficient.

1:it seems datagroup can't be used in switch

 

2:I use [HTTP::path] to evaluate each url included in the request to hit the bigip,it seems it matches what has been said in this link

 

 

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/281/Ten-Steps-to-iRules-Optimization.aspx

 

Jucao,

 

 

What are you actually trying to do? Do you want to see if an HTTP path ends with a set of extensions?

 

 

If so, you could either use a switch statement or the class command with the ends_with operator and a datagroup. There isn't a logical way to combine a switch statement and a class lookup in one operation. From Joe's testing, a datagroup is probably more efficient than a switch statement if you consider matches in the beginning, middle and end of the list of strings:

 

 

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/1086424/Comparing-iRule-Control-Statements.aspx

 

 

However, when using a small list of strings (<100) the results are close enough that it probably makes sense to choose a switch statement if it's easier for you to manage the strings inline within the iRule instead of in a datagroup.

 

 

Aaron

Hi,Aaron

 

sorry for making any confusion here

 

they are 2 different questions

 

 

1:I want to know whether datagroup can be applied in switch synatx

 

 

2:I 'd like to know in wich case I should use variable

 

like set path [HTTP::path]

 

switch -glob $path { "*jpg" - "*bmp" - "*gif" - "*png" - "*img" - "*ico" - "*js" - "*css" - "*swf" - "*swz" - "*vbs" - "*html" - "*htm" - "*csv" - "*txt" - "*crossdomain.xml" {pool xyz}

 

 

or switch -glob [HTTP::path] { "*jpg" - "*bmp" - "*gif" - "*png" - "*img" - "*ico" - "*js" - "*css" - "*swf" - "*swz" - "*vbs" - "*html" - "*htm" - "*csv" - "*txt" - "*crossdomain.xml" {pool xyz}

 

 

I have read one link to ask me to use variable if we need to evaluate it repetitively

 

 

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/281/Ten-Steps-to-iRules-Optimization.aspx

 

6- Use Variables

 

Hi jucao,

As Hoolio pointed out, if you are after efficiency then you can go with a switch statement over a Data Group. Some (myself included) view management of a Data Group easier to keep track of (and you can make modifications without having to alter your iRule).

You can so it with something like:

when HTTP_REQUEST {
if { [class match [string tolower [HTTP::uri]] ends_with image_types ] } {
pool image_server_pool
}
else {
pool content_server_pool
}
}

1: I want to know whether datagroup can be applied in switch syntax

 

 

No. A switch statement can't reference a datagroup.

 

 

2: I 'd like to know in which case I should use variable

 

 

As you're only referencing HTTP::path once there isn't any reason to use a variable. If you were running an operation against a command multiple times you'd want to run it just once and then save the output to a variable. For example, if you were setting a URI to lower case and checking it multiple times, you'd want to save the lower case URI rather than running string tolower multiple times.

 

 

Aaron

oh,I got u

 

so for example :

 

 

switch -glob [HTTP::path] {

 

"*gif" -

 

"*png" {

 

switch -glob [HTTP::path] {

 

"/static.*" -

 

"/s.*" {

 

switch -glob [HTTP::path] {

 

"*cswebtool*" -

 

"*cobrands*" {

 

persist none

 

pool SRWD52-STATIC

 

return

 

}

 

}

 

}

 

}

 

}

 

in this case ,I can save the output of HTTP::path to a variable,right? because I run [HTTP::path] 3 times

hmm,I should use variable if one command run more than 1 time,right?