Forum Discussion

Kris__109062's avatar
Kris__109062
Icon for Nimbostratus rankNimbostratus
Oct 31, 2008

iRule to Select alternate pool member based on QUERY_STRING

Hi,

 

 

I have the following iRule setup (define_node) which allows me to force a pool member to be selected if I add ?node=01 , ?node=02 & ?node=03 to the query string..

 

 

Now the rule works and I am presented to the correct node but my problem is that subsequent requests do not persist if I take off ?node=01 from the QUERY_STRING

 

 

ie. http://intranet/?node=01 binds me to member 192.168.49.97 which is correct if you follow the irule logic below but subsequent requests eg. http://intranet/ might take me to other members in the pool.

 

 

How do I make it so that once ?node=01 is executed my persistence stays on that node ?

 

 

Irule (define_node)..

 

 

when HTTP_REQUEST {

 

set default_pool [LB::server pool]

 

set thenode [ findstr [string tolower [HTTP::uri]] "node=" 5 2]

 

if { $thenode == "01" } {

 

pool $default_pool member 192.168.49.97

 

}

 

if { $thenode == "02" } {

 

pool $default_pool member 192.168.49.98

 

}

 

if { $thenode == "03" } {

 

pool $default_pool member 192.168.49.99

 

}

 

}

 

 

virtual intranet_80 {

 

pool pool_intranetapp_80

 

destination 192.168.48.25:http

 

ip protocol tcp

 

vlans external_480 enable

 

rules

 

define_node

 

profiles

 

http

 

tcp

 

persist source3600

 

}

 

 

pool pool_intranetapp_80 {

 

lb method member observed

 

monitor all http_80

 

members

 

192.168.49.97:http

 

192.168.49.98:http

 

192.168.49.99:http

 

}

 

 

profile persist source3600 {

 

defaults from source_addr

 

mode source addr

 

timeout 3600

 

}

 

application delivery
dev
devops
iRules

4 Replies

Sort By
  • hwidjaja_37598's avatar
    hwidjaja_37598
    Icon for Altostratus rankAltostratus
    Oct 31, 2008
    Try this out: 

      
  when HTTP_REQUEST {   
  set persistTo [session lookup \ 
 source_addr [IP::client_addr]]  
  set default_pool [LB::server pool]   
  set timeOut 3600  
    
  switch [ findstr [string tolower \ 
 [HTTP::uri]] "node=" 5 2] {  
  01 { set persistTo 192.168.49.97 }  
  02 { set persistTo 192.168.49.98 }  
  03 { set persistTo 192.168.49.99 }  
  }  
    
  if {$persistTo eq ""} {  
  pool $default_pool   
  } else {  
  pool $default_pool member $persistTo  
  session add source_addr [IP::client_addr] \ 
 $persistTo $timeOut  
  }  
    
  }

    Hope it helps.
  • Kris__109062's avatar
    Kris__109062
    Icon for Nimbostratus rankNimbostratus
    Nov 02, 2008
    Hi hwidjaja,

     

     

    Thanks for your prompt response.

     

     

    It works perfectly now.

     

     

    Cheers

     

    Kris
  • aaronactive_227's avatar
    aaronactive_227
    Icon for Nimbostratus rankNimbostratus
    Oct 13, 2015

    Hi There,

    Has something changed since this used to worK?

    Just trying it out now and I get this message when trying to save the iRule:

    01070151:3: Rule [Define_Persist_Member] error: line 2: [wrong  args] [session lookup \ ] line 3: [undefined procedure: source_addr] [source_addr [IP::client_addr]]