iRule send CPU utilization to 100%

I don't know about the profiles, but see if this helps:

when HTTP_REQUEST {
    HTTP::respond 200 content {
         "Site unavailable
    
    
    
    System Maintenance
    Argos is down for some emergency maintenance.  We apologize for the inconvenience.  At this time we expect Argos to be back up and running by 1 pm on Wednesday, January 28.
    "
         } "Connection" "Close"

     event disable all
     return
}

Thanks Micheal. Are you saying that the connection stays open after the irule runs? And that's why you added the "Connection" "Close" statement? Also, does "return" essentially "exit" the VIP? If so, what happens at the client? Will the system down page stay in the client's browser?

Thanks again

Hi Danny,

I agree with Michael J. It´s probably the applied profile mix ... It may help to reproduce the issue (not on production system of course), to take a tcpdump and to watch the logs.

Regarding the iRule:

I would remove the quotes, add the doctype declaration to the content, replace the server header, add the content type header and do a connection close.

when HTTP_REQUEST {
    HTTP::respond 200 content {
        
        
            
                
                    Site unavailable
                
            
            
                
                
                    
                        System Maintenance
                    
                    Argos is down for some emergency maintenance.  
                    We apologize for the inconvenience.  
                    At this time we expect Argos to be back up and running by 1 pm on Wednesday, January 28.
                
                
            
        
    } noserver Server Argos Connection Close Content-Type text/html
    return
}

Thanks, Stephan

Thanks Michael and Stephan. Ill try these suggestions.

And Ill report back

The irule works now without spiking the CPU on the F5. Thanks for the help.

As I mentioned the irule works now. However, we are noticing very inconsistent results from the different clients hitting the website. Some people get the "system down" page, others just get a spinning circle as firefox tries to load the site. We tried firefox, chrome and ie. We cleared the cache and cookies for each browser. What we found is that IE works 100% of the time. Firefox and Chrome don't work. Eventually after about 10 minutes, all the browsers get the systemdown page, but only IE works right away. I tried disabling persistence to see if that helps, but it did not. Any idea why the browsers would behave this way?

Thanks, I'll try that.

Also, in the following line, what does "noserver Server Argos" do? I'm planning to reuse this irule with all of my VIPs, but it should not reference the Argos server. Is this just a comment?

"noserver Server Argos Connection Close Content-Type text/html"

Good info. Thanks again for all your help

so the 100% CPU was caused by ? Any conclusion at last?