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Yazid_Abdesslam's avatar
Yazid_Abdesslam
Icon for Nimbostratus rankNimbostratus
Jul 26, 2017

Limit Traffic on Virtual server & redirect it to "Busy" Web page

Hello,

 

We got slowness on an application that receives huge traffic. In order to troubleshoot the problem on Web & App side, we are asked to Limit traffic on it & Redirect postponed requests, or requests over limit, to a server containing a response for example "Web server is actually busy... try again later ...." & this, in order to contain them.

 

I'm thinking of an iRule, but I don't know how I can identify requests that are in Time Wait state or somthing like this.

 

regards,

 

application delivery
LTM

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  • crodriguez's avatar
    crodriguez
    Ret. Employee
    Jul 26, 2017

    You don't need an iRule to implement this functionality. Priority Group Activation could be used with connection limit instead. Specify a connection limit on all your normal pool members and assign them all priority 10. Add the "apology server" (the one that sends the "Sorry, we're busy" message) as a pool member with priority 1. Set the Priority Group Activation to "Less than 1" member. If and when all the normal servers reach their connection limits, the apology server pool member will be activated and clients connecting to it will receive the "Sorry" message. When one of the normal members once again is below its connection limit, it will start accepting new connections, and the apology server will be "deactivated" until it is needed again. ("Deactivated" meaning it's there, but won't be used for load balancing decisions.) See https://devcentral.f5.com/questions/priority-group-activation-why-use-it