0 Replies Latest reply on May 23, 2014 1:18 PM by cgregors

    Changing the caption on an existing node seems to break UDP data collection and relationship in db



      1. Create a custom poller for sysUpTime.
      2. Add a node to NPM using the non-FQDN.
      3. Assign Poller sysUpTime to node.
      4. Time goes by and data gets collected.
      5. Edit the node and change the caption from the non-FQDN to the FQDN
      6. Time goes by and no data gets collected.


      Dissection of problem:


      • It appears that the relationship between the node and the custom poller is stored in the database in the CustomPollerAssignment table
      • This sql will return the relationship between the custom poller and the node

      select nodes.caption,nodes.nodeid

      from nodes,CustomPollerAssignment

      where nodes.nodeid=CustomPollerAssignment.nodeid and CustomPollerAssignment.AssignmentName='sysUpTime on hostname';

      • Notice that the AssignmentName contains the caption of the node.
      • When the caption of the node changes to FQDN the CustomPollerAssignment table doesn't get updated with the change in the AssignmentName name.


      Work Around:

      • Unassign the custom poller from the node
      • Assign the custom poller to the node
      • The CustomPollerAssignment table gets updated with a new AssignmentName that includes the FQDN caption. example AssignmentName = 'sysUpTime on hostname.example.com'
      • Data starts collecting again.
      • Use CustomPollerAssignmentView instead of CustomPollerAssignment when writing sql

      select nodes.caption,nodes.nodeid

      from nodes,CustomPollerAssignmentView

      where nodes.nodeid=CustomPollerAssignmentView.nodeid and CustomPollerAssignmentView.AssignmentName='sysUpTime on hostname.example.com'

      Unresolved issues:

      • Detecting the situation is difficult.
      • Historical data is lost when the poller is re-assigned.
      • Node pages that display graphs for Custom pollers never finish loading data.
      • Node pages are not using the CustomPollerAssignmentView for rendering custom poller graphs.
      • The CustomPollerAssignmentView has poor performance.
        • When running a sample query against the CustomPollerAssignment table the execution time is around 10ms
        • When running a sample query against the CustomPollerAssignmentView the execution time is around 6 seconds


      Is this a bug ?