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Miron_du_Plessi's avatar
Miron_du_Plessi
Icon for Nimbostratus rankNimbostratus
Sep 27, 2010

Hiding Web Server

Hi,

 

 

We have a current requirement that involves serving web content from two separate web servers trying to make them look like the same from the clients perspective. (this is for migration purposes)

 

 

Essentially what we would like is if the new web server(A) does not have the content the user requests , the BIGIP through an irule will capture the 404 error from A then itself check if the content exists on B and serve it to the client. This is so that the client does not have to be given a redirect to the old server and is therefore oblivious to where the content was retrieved.

 

 

Currently we have only been able to have the LTM redirect the client. so the client makes a connection to www.a.com/oldcontent they will get a redirect top www.b.com/oldcontent so the client willl see the difference.

 

 

do you know if it is possible to hide the webserver.

 

 

Kind Regards

 

 

Miron
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  • Hamish's avatar
    Hamish
    Icon for Cirrocumulus rankCirrocumulus
    Sep 27, 2010
    Interesting option... Yes it should be possible. The SERVER_RESPONSE event is the one to use to detect the 404. Then it should be possible to select a different poolmember and reissue the request...

     

     

    You'd need to keep a bit of state so you don't get stuck in a forever loop if the document genuinely doesn't exist though.

     

     

    H
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Sep 27, 2010
    As Hamish suggested, you can check the server response code in HTTP_RESPONSE. You can use HTTP::request in HTTP_REQUEST to save the HTTP request headers. You can use HTTP::retry to retry the request. If you need to potentially retry requests with payloads, you would need to collect the request payload in HTTP_REQUEST with HTTP::collect and then access the payload in HTTP_REQUEST_DATA using HTTP::payload.

     

     

    Here is a post with a related example:

     

     

    Redirect if error

     

    http://devcentral.f5.com/Default.aspx?tabid=53&view=topic&postid=812647&ptarget=812648

     

     

    And here is the main HTTP wiki page where you can get details on the mentioned commands and events:

     

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

     

     

    Aaron