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David_Patino_20's avatar
David_Patino_20
Icon for Nimbostratus rankNimbostratus
May 04, 2012

Instructing BigIP to expire RAM Cache when it receives a URL Query

Howdy Everyone. I've an issue I've been working on. I'm trying to develop a irule that will check the URI::query for an expire entry. If it finds one, it will instruct the system to do a CACHE...
application delivery
dev
devops
iRules
hooleylist's avatar
hooleylist
Icon for Cirrostratus rankCirrostratus
May 04, 2012
Hi David,

Can you try this without the redirect? Also, you can parse the URI without the query string using HTTP::path. To get just the query string you can use HTTP::query. 

when HTTP_REQUEST {
 Disable cache for a defined set of folders
if { [class match [HTTP::uri] contains folders_to_not_cache] }{
CACHE::disable
return
}

if { [string tolower [HTTP::query]] starts_with "expire" } {
log "Request to expire [HTTP::path] received."
set expire_cache_trigger 1

 Remove the query string from the URI
HTTP::uri [HTTP::path]
}
}

when CACHE_REQUEST {
if { ( [info exists expire_cache_trigger] ) && ( $expire_cache_trigger==1 ) } {
CACHE::expire
log "Cache Expired"
unset expire_cache_trigger
}
}

Aaron