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Dave_73612's avatar
Dave_73612
Icon for Nimbostratus rankNimbostratus
Jul 01, 2009

Multiple 301 redirects and F5 performance

Hi guys,

 

 

I have a requirement to do over 40 301 redirects (google ranking purposes) for one of our websites which I was going to implement via IRule attached to the Virtual server for the site.

 

 

The IRule is structured as follow's:

 

 

when HTTP_REQUEST {

 

if { [HTTP::uri] equals "/index.html" } {

 

HTTP::respond 301 Location "blah"

 

}

 

if { [HTTP::uri] equals "/index.html" } {

 

HTTP::respond 301 Location "blah"

 

}

 

if

 

etc covering the 40 redirects.

 

 

I am wondering if there is a "faster" way to write this code?

 

 

Would url rewrites be of any benefit?

 

 

What is the performance overhead of running this Irule?

 

 

Is this the right approach?

 

 

Thanks in advance,

 

 

Dave

 

 

 

application delivery
dev
devops
iRules

11 Replies

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  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 01, 2009
    Hi Dave,

     

     

    A switch statement would probably be easier to manage and be more efficient. Can you provide a few more examples of the mappings between requesteed URI and the redirect locations?

     

     

    Thanks,

     

    Aaron
  • Dave_73612's avatar
    Dave_73612
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2009
    Thanks for the reply,

     

     

    Mappings are based on the explicit URI string and are usually redirecting, for example: www.blah.co.uk\blah\index.htm to www.blah.co.uk\blah.

     

     

    Another example would be www.blah.co.uk\blah\blah\index.htm to www.blah.co.uk\blah\blah and so on for 40 different uri's.

     

     

    Cheers,

     

     

    Dave
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 02, 2009
    Is there any pattern to the rewriting? Can you say that you always want to redirect //index.htm to /? Or is it something you need to explicitly map out as 'if URI is "this" redirect to "that"?

     

     

    Aaron
  • Dave_73612's avatar
    Dave_73612
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2009
    Yes, it's always redirecting /something/index.htm to /something.

     

     

    Mind you it could be /something/something/something/something/index.htm to /something/something/something/something/.

     

     

    Regards,

     

     

    Dave
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 03, 2009
    I assume the application won't redirect the client back to /something/index.htm. How about this then: 

     
 when HTTP_REQUEST { 
  
     Check if request ends with /index.htm 
    if {[HTTP::path] ends_with "/index.htm"}{ 
  
       HTTP::respond 301 Location "[string map {/index.htm ""} [HTTP::uri]]" 
       log local0. "Redirecting to [string map {/index.htm ""} [HTTP::uri]]" 
    } 
 }

    Note that RFC2616 states the Location header value must be a fully qualified domain name, but browsers accept a local URI. You may want to hardcode the protocol and domain in the iRule.

    Aaron
  • Dave_73612's avatar
    Dave_73612
    Icon for Nimbostratus rankNimbostratus
    Jul 03, 2009
    Right,

     

     

    If that works that would be fantastic.

     

     

    I will give it a test in staging today - Thanks for the help.

     

     

    D
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 03, 2009
    If your site has an index.htm file in the root (/index.htm) you would probably not want to redirect clients who request it to a null URI. So you might want to add a check for a path not equal to /index.htm before rewriting it: 

     
     if {[HTTP::path] ends_with "/index.htm" and not ([HTTP::path] eq "/index.htm")}{

    Aaron
  • Dave_73612's avatar
    Dave_73612
    Icon for Nimbostratus rankNimbostratus
    Jul 03, 2009
    Edit - Ok after re-reading that addition, it wont be fit for purpose.

     

    One of the required redirects is for example www.blah.com/index.htm to www.blah.com.

     

    The default page of all folders is index.htm - we are doing this so as not to dilute google rankings.

     

    D
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 06, 2009
    So you do want to redirect a request for /index.htm to / ? If so, you could just check for /index.htm and replace it with / in the redirect: 

     
  when HTTP_REQUEST {  
  
      Check if request ends with /index.htm  
     if {[HTTP::path] ends_with "/index.htm"}{  
  
        HTTP::respond 301 Location "[string map {/index.htm /} [HTTP::uri]]"  
        log local0. "Redirecting to [string map {/index.htm /} [HTTP::uri]]"  
     }  
  }

    Aaron
  • Dave_73612's avatar
    Dave_73612
    Icon for Nimbostratus rankNimbostratus
    Jul 06, 2009
    As long as that only redirects the last section to / that's ok.

     

     

    For example:

     

     

    www.blah.com/blah/blah/index.htm needs to be redirected to www.blah.com/blah/blah/ not to www.blah.com/