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Wil_Schultz_101's avatar
Wil_Schultz_101
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Aug 14, 2006

Long URIs and iRules... Bug?

We seem to have possibly found a bug in our F5's, version 4.6... Wondering if anyone else has experienced this...

 

 

We use an iRule with 23 statements, not huge but not that small either...

 

 

Recently a crawler found a loop in our website and soon found itself send GET requests that were over 8000 chars in length. While this crawler was misbehaving we found that the BigIp was actually dropping packets through it, even going directly to a NAT address. Our graphs show that the load was normal (about 2) and CPU was normal (about 0.3%) yet traffic had slowed from about 20mbps to about 8mbps.

 

 

I'm fairly certain that the iRules + long URIs caused this slow down, but I'm having a difficult time understanding why it was dropping packets since the load, cpu and traffic were all at or below normal.

 

 

Thanks in advance!

2 Replies

  • FYI, I've come up with the following workaround for now...

     

     

    else if (substr(http_uri, 0) > 255) {

     

    redirect to "http://www.mysite.com" + substr(http_uri, 0, 254)

     

    }

     

     

    Keeps a given URI checked at 255 chars in length...
  • I'm thinking at some point in 4.x that URI processing within iRules was limited to 255 characters, I'm not sure if that continued through 4.6 but it wouldn't surprise me.

     

     

    Denny