Forum Discussion

Aaron_5359's avatar
Aaron_5359
Icon for Nimbostratus rankNimbostratus
Apr 01, 2008

Adding wait() before restoring service

I'd like to wait x seconds after the HTTP health check succeeds before bringing the pool member(s) online.

 

 

I imagine this would require an external script?

 

 

Thanks!

 

 

Aaron

3 Replies

  • You can get similar behavior using the 'slow ramp time' option on the pool:

     

     

     

    Slow Ramp Time

     

     

    The duration during which the system sends less traffic to a newly-enabled pool member. The amount of traffic is based on the ratio of how long the pool member has been available compared to the slow ramp time, in seconds. Once the pool member has been online for a time greater than the slow ramp time, the pool member receives a full proportion of the incoming traffic. Slow ramp time is particularly useful for least connections load balancing mode.

     

     

     

     

    But as cmbhatt said, to get the exact behavior, you'd need to write a script which delays the UP response for x number of seconds after the node responds.

     

     

    Aaron
  • Deb_Allen_18's avatar
    Deb_Allen_18
    Historic F5 Account
    If you go the monitor route, be sure the monitor interval is long enough to accommodate the request+longest possible response time+wait time, or the pool member will never be marked UP. Interval is more important than timeout for external monitors that are expected to hang around for a while after the action is over.

     

     

    Here's the relevant detail:The Timing

     

     

    The interval is the amount of time that will elapse between the start of each monitor attempt. In order to avoid creating a Denial of Service situation by sending your servers excessive monitor traffic, you should increase the interval as much as possible. The interval MUST be longer that the longest possible healthy response should take, since each successive instance of the script run against a pool member will kill off any already-running previous instances, assuming they are hung and will never complete.

     

     

    from this article about implementing external monitors: Click here

     

     

    /d