Conference lassie::ucx

5370.0. "Impersonator on a three nodes cluster" by BLG03::SALVATORELLI () Fri Mar 21 1997 10:22

    Hi everybody,
    
    my customer has got the following scenario:
    
    Three AXP systems in cluster with OpenVMS V6.2-1H3
    and TCP services V4.1 ECO04
    
    The three systems have the following TCP configuration:
    
    Internet address 113.41.10.31   32  33
    Cluster  address 113.41.10.30   30  30
    
    They have an application which is started manually on node1
    At application start time node1 is forced to be the impersonator
    by giving the command:
    set inter WE0/cluster="alias"
    
    On the three nodes the cluster_timer parameter is set to 5
    
    For some reasons sometimes they have to stop the application on 
    node1 (and disable the impersonator) and start it on node2 
    which also has to become the impersonator.
    
    The problem at this stage is that once on node1 they disable the
    impersonator, before they can force node2 to become the impersonator, 
    node3 becomes impersonator and this cause users to connect to
    a system which is not the one where the application resides.
    
    What I am wandering at this stage is:
    is it possible to avoid node3 to become impersonator?
    
    I hope I described the situation clearly enough.
    
    Thanks for your help in advance
    
     		Marilena
    
    

    
    Hi there,
    
    does anybody have any idea or suggestions?
    
    Thanks              
    		Marilena

There is no way to influence which of the other two nodes will become the
impersonator. As far as I know, it is determined by the sequence in which
the nodes were booted (ie ucx started).

If you don't want node 3 to become the impersonater, just disable cluster
alias on that one before failing over from node 1.

Regards,

Oswald

    Yeah, just disable alias on all nodes EXCEPT the one where the
    application is currently running. Setting/clearing alias is dynamic.
    
    Colin.