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lmiestc_26212's avatar
lmiestc_26212
Icon for Cirrus rankCirrus
Oct 27, 2009

iRules and RAM Cache

Hi,

 

I am new to iRules and I hope somebody can help me. I am using the RAM cache. Everything that can be cached by default is cached for 24 hours in the RAM cache. Now to my problem. I need to cache a response to a query so I created an iRule

 

 

when HTTP_REQUEST {

 

if { [HTTP::path] equals {/mywebpage/public/test/testList.ajax}} {

 

CACHE::enable

 

}

 

}

 

 

I think this reads the uri path up until the ? before the query.

 

 

The problem is that I need to expire this specific entry in the cache if it is older than two hours and if there is a request for it. While the rest in the cache should remain for 24 hours.

 

 

I don't know exactly how to write the iRule for this.

 

I have seen the below iRule and I think it can be modified.

 

So the flow should be if there is a HTTP request to where the URI path equals /mywebpage/public/test/testList.ajax and there is a cache hit, check the age if > 7200 if so expire it else send the response from cache to the client.

 

 

when CACHE_REQUEST {

 

if { [CACHE::age] > 7200 } {

 

CACHE::expire

 

log local0. "Expiring content: Age > 7200 seconds"

 

}

 

}

 

 

I'm hoping someone can help me :-)
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iRules
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Oct 27, 2009
    Maybe something like this? 

     
 when HTTP_REQUEST { 
     
    set path [HTTP::path] 
 } 
 when CACHE_REQUEST { 
    if { $path equals "/mywebpage/public/test/testList.ajax" && [CACHE::age] > 7200 } { 
       CACHE::expire 
       log local0. "Expiring content: Age > 7200 seconds" 
    } 
 }

    Aaron