Re-LB to apologize server without redirect when server doesn't respond

Hi,

 

Some overloaded servers(and databases behind application server) are able to do 3WAY handshake with LTM but they don't respond any application data even HTTP status code.

 

In this "no L7 response for specific URI" case, I want iRules to re-send the HTTP request to another server in different pool. Apologize server for instance.

 

Now I am trying to do this using "after" TCL command in v10 but I haven't get to work.

 

Here is tiny sample script for the solution I am working on.

 

 

 
 when HTTP_REQUEST { 
 set retry 0 
 set http_request [HTTP::request]  
 after 5000 { 
 log local0. "reselect"  
 LB::down 
 LB::detach 
 } 
 } 
 

 

 

I could see "reselect" log message on /var/log/ltm but LB::down and LB::detach weren't invoked by checking tcpdump in serverside.

 

 

I may don't understand usage of after 100%... please advice how I solve my original issue.

 

 

Thanks!