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Darren_Person_2's avatar
Darren_Person_2
Icon for Nimbostratus rankNimbostratus
Nov 07, 2006

CDN Integration / Failover in an iRule?

Hi All,

 

 

I'm interested in learning if this is possible with iRules. As a high trafficked site, we can never account for spikes with our existing infrastructure. I'd like to know if it's possible to create an iRule which will monitor CPU levels and then automatically engage a CDN when the threshold has been reached (80%).

 

 

For example:

 

we have static.domain.com with a CDN CNAME to cdn.static.domain.com

 

 

All requests for static content should go to our domain (static.domain.com) as long as our servers can handle the load. Once our CPU utilization hits 80%, we'd like the failover pool to be the cdn.static.domain.com url (the uri would be appended, but the domain would be different)

 

 

Any thoughts on how this can be achieved?

 

 

Thanks in advance - you guys have been terrific with responses and I greatly appreciate it! I think an answer to this question will provide all your customers with a great ability to truly provide unlimited scale if they are willing to engage a cache or CDN.
application delivery
dev
devops
iRules

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  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    Nov 07, 2006
    This can be accomplished without iRules with the snmp_dca monitor and defining your fallback host as your CDN. Take a look at the handy dandy configuration manual on ask.f5.com.
  • sc2397_128053's avatar
    sc2397_128053
    Icon for Nimbostratus rankNimbostratus
    Nov 17, 2006
    While not exactly the same, I have a related question:

     

     

    is it possible to take some action (e.g. run a script, make a Web Service call) based on the information available to an iRule?

     

     

    I'd like to have a collection of physical servers, a few different VMWare virtual server configurations at the ready, and the ability to automatically "provision" a virtual server by making a call to VMWare (and adding it to a pool) when certain situations come up.

     

     

    This would let me re-purpose servers in real-time as I need them for different systems.

     

     

    Thanks,

     

    Scott
  • Colin_Walker_12's avatar
    Colin_Walker_12
    Historic F5 Account
    Dec 07, 2006
    Currently the only way to do this would be to log a statement via the iRule and have syslog perform some action upon seeing that statement in the logs.

     

     

    There is no direct trigger to execute a script via iRules.

     

     

    Colin