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Angel_Martinez_'s avatar
Angel_Martinez_
Icon for Nimbostratus rankNimbostratus
Nov 19, 2010

LB::server pool

Hi

 

 

I've this iRule running in two different boxes:

 

 

rule iRule_Sorry_Redirect {

 

when LB_FAILED {

 

if { [active_members [LB::server pool]] < 1 } {

 

HTTP::fallback "http://sorry-[HTTP::header host]"

 

}

 

}

 

}

 

 

On 6800 9.4.8 HF4 box is set up for 27 Virtuals without any problem at the /var/log/ltm. And the statistics says:

 

 

RULE iRule_Sorry_Redirect

 

+-> LB_FAILED 5042 total 0 fail 0 abort

 

 

 

 

But on the 6900 also 9.4.8 HF4 is only set up for 1 Virtual with this continous message at the log file:

 

 

Nov 19 08:47:18 tmm1 tmm1[2141]: 01220001:3: TCL error: iRule_Sorry_Redirect - no such pool Failed Tcl_pool_GetFromObj: pool (line 1) invoked from within "active_members [LB::server pool]"

 

 

RULE iRule_Sorry_Redirect

 

+-> LB_FAILED 269 total 269 fail 0 abort

 

 

It could be related with the CMP feature? On BIG-IP 6800 boxes CMP is not supported meanwhile on BigIP 6900 is working with this feature by default. I can read this from the 9.4.8 Release Notes:

 

 

Global variable in iRule and CMP (CR93820)

 

In this release, if an iRule containing a global variable is removed from a virtual server, the virtual server is eligible for full Clustered Multi-Processing (CMP), rather than remaining relegated to a single Traffic Management Microkernel (TMM).

 

 

So am I using a Global variable at my iRule ¿? any idea about my problem ¿?

 

 

Thanks in advanced.

 

 

 

 

 

 

 

 

application delivery
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  • Chris_Miller's avatar
    Chris_Miller
    Icon for Altostratus rankAltostratus
    Nov 19, 2010
    I'd start off by logging. 

    
rule iRule_Sorry_Redirect {
   when LB_FAILED {
   log local0. "Pool was [LB::server pool]"
  if { [active_members [LB::server pool]] < 1 } {
    HTTP::fallback "http://sorry-[HTTP::header host]"
         }
}
}

That'll log to the LTM logs. You aren't using any variables in your rule.
  • Chris_Miller's avatar
    Chris_Miller
    Icon for Altostratus rankAltostratus
    Nov 19, 2010
    As I think about this more, I don't understand how LB::server pool can be used from LB_FAILED even though the wiki page says it can be. Let's see the value you log I guess...

     

     

  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Nov 19, 2010
    Yeah, I'm not sure whether LB::server pool would return the VS default pool in LB_FAILED. If it doesn't, you could save the name of the pool in CLIENT_ACCEPTED and then reference that variable in LB_FAILED. Similarly, I don't know if HTTP::host would be available then either. 

    
when CLIENT_ACCEPTED {
   set default_pool [LB::server pool]
}
when HTTP_REQUEST {
   if {[HTTP::host] eq ""}{
      set host [IP::local_addr]
   } else {
      set host [HTTP::host]
   }
}
when LB_FAILED {
   if { [active_members $default_pool] < 1 } {
      HTTP::fallback "http://sorry-$host"
   }
}

    Aaron
  • Angel_Martinez_'s avatar
    Angel_Martinez_
    Icon for Nimbostratus rankNimbostratus
    Nov 24, 2010
    Thank you people!!!

     

     

    I've been some days out of the office and I didn't check the answers... as soon as I can I'll try your advices...

     

     

    Thanks again!

     

  • Angel_Martinez_'s avatar
    Angel_Martinez_
    Icon for Nimbostratus rankNimbostratus
    Nov 25, 2010
    Hi

     

     

    I had time to test...

     

     

    $default_pool is always pool_ni.cm.es_80 which is the default pool of the virtual server. So, I should use the event CLIENT_ACCEPTED to be sure that iRule manages the correct pool it a great idea.

     

     

    I'm going to set up on the production enviroment this iRule:

     

     

    rule Sorry-Redirect {

     

    when CLIENT_ACCEPTED {

     

    set default_pool [LB::server pool]

     

    }

     

     

    when LB_FAILED {

     

    if { [active_members [LB::server pool]] < 1 } {

     

    HTTP::fallback "http://sorry-[HTTP::header host]"

     

    }

     

     

    }

     

     

     

    I've tried on the pre-production enviroment but I need load to be sure that works right.

     

  • Angel_Martinez_'s avatar
    Angel_Martinez_
    Icon for Nimbostratus rankNimbostratus
    Nov 26, 2010
    Hi !

     

     

    It seems to be working right:

     

     

    :Active] ~ b rule iRule_Sorry_Redirect list

     

    rule iRule_Sorry_Redirect {

     

    when CLIENT_ACCEPTED {

     

    set default_pool [LB::server pool]

     

    }

     

     

    when LB_FAILED {

     

    if { [active_members $default_pool] < 1 } {

     

    HTTP::fallback "http://sorry-[HTTP::header host]"

     

    }

     

    }

     

    }

     

    Active] ~ b rule iRule_Sorry_Redirect

     

    RULE iRule_Sorry_Redirect

     

    +-> CLIENT_ACCEPTED 7667 total 0 fail 0 abort

     

    +-> LB_FAILED 5 total 0 fail 0 abort

     

  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Nov 29, 2010
    Hi Angel,

     

     

    Thanks for posting the results of your testing. Glad the last version is working for you.

     

     

    Aaron
  • Chris_Miller's avatar
    Chris_Miller
    Icon for Altostratus rankAltostratus
    Nov 29, 2010
    Aaron -should CLIENT_ACCEPTED be added to the events from which LB::server pool can be called? The wiki page doesn't list it.

     

     

    http://devcentral.f5.com/wiki/default.aspx/iRules/LB__server.html