Forum Discussion

Scott_Carlile_8's avatar
Scott_Carlile_8
Icon for Nimbostratus rankNimbostratus
Apr 19, 2010

Monitor all but Last?

We have a pool with 7-10 servers in it. The monitor is a simple http send string of GET /testpage.aspx , and expect a receive string of "Site_Up" So far, very easy to do. The app dev folks want me to stop running a monitor when there is only one server left (i.e. never take the last server out of the pool). Hopefully this is easy, and I am overlooking the obvious. This is an LTM version 9.3.1
management
monitoring
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Apr 19, 2010
    Hi Scott,

    I can't think of a simple way to stop monitoring the pool if the available pool member count drops to one. And if you could do this, how would you know if any of the other pool members had come back to life?

    You could add one or more pool members to a second pool and not configure a monitor on that pool. You could then use an iRule which checks if the main pool has no available members and then selects the second pool.

    The rule could be something like: 

    
when CLIENT_ACCEPTED {

    Check if the VS's default pool has no active members
   if { [active_members [LB::server pool]] == 0 } {

       Select the second pool
      pool standby_pool
   }
}

    Aaron