Forum Discussion

Welson_Alexandr's avatar
Welson_Alexandr
Icon for Nimbostratus rankNimbostratus
Jul 27, 2005

"Dynamic Provisioning" of hosts

Using IControl / IRules, I want to be able to dynamically provision a "stand-by" server. Basically, when any particular pool exceeds a threshold that we define (total CPU Utilization, total RAM utilization, maximum number of concurrent connection or any combination of the aforementioned, etc....), I would like the load balancer (LB) to do the following:

 

 

a) Execute an installation package that resides on a "stand-by" server(s). Is this configurable? Can the LB be made aware of multiple stand-by hosts?

 

b) Add that server(s) to the LB that has had it's threshold exceeded.

 

c) When the pool threshold is no longer exceeded, remove the "stand-by" host from the affected pool, and un-install the package that was installed.
dev
devops
iControl
v4

1 Reply

Sort By
  • bknotwell_12713's avatar
    bknotwell_12713
    Historic F5 Account
    Jul 27, 2005
    Hi Alexandre--

     

     

    Depending on your performance requirements and the load on your BIGIP, you might not need iControl at all. Specifically, you might just write a simple shell to gather metrics, make overload decisions, do remote (de)installs, and issue the appropriate bigpipe commands.

     

     

    Now, in the context of iControl, you might use a separate machine (I might use the standby with the understanding that I'd lose my provisioning capability for a bit when failovers occur) do all the work above. iControl calls to the active box would be used to gather the metrics and change the BIGIP's configuration.

     

     

    Finally, unless you're trying to minimize software license costs by temporary installations, I'd simplify the problem set slightly by removing the (de)installation requirements and just leaving the software always installed. Everything else remains the same.

     

     

    Good luck!

     

     

    --Brad