iRule redirection seems to cause problem under heavier load

Hi All,

 

 

We're running a redundant pair of BigIP 1500s to load balance a Blackboard Vista cluster. I created an iRule this morning to redirect autosignon failures from our student portal to a more user-friendly error page than the default page provided with the application.

 

 

The rule was enabled around 8 this morning and has been running fine up until now. The user load has gone from under 100 to about 400. The iRule text is:

 

 

*****

 

when HTTP_RESPONSE {

 

HTTP::collect 384

 

}

 

when HTTP_RESPONSE_DATA {

 

if { [HTTP::payload] contains "Autosignon Error" } {

 

HTTP::redirect "http://bellevuecollege.edu/distance/bbredirectss.asp" }

 

}

 

*****

 

 

The behavior I've noticed and verified is that earlier this morning, with fewer users, Vista ran at normal speeds. At the present time, with the rule enabled, the login page is extremely slow to load, and may time out.

 

 

I've had to create the iRule this way due to the application behavior- if a user with a disabled account experiences an autosignon failure, Vista does not return a 404 error, it returns a 200 message along with a sparse autosignon error page.

 

 

I've checked the traffic manager performance and do not see anything to indicate that the processing of the iRule is exceeding system resources.

 

 

I'd appreciate any suggestions you have for troubleshooting this issue.

 

 

Thanks in advance!

 

 

Ed