Conference pamsrc::decmessageq

    
    I haven't tried OBB in a DECsafe environment but I have setup DMQ on 2
    UNIX clusters. Basic things to note are :-
    
    1. Give the hosts in DECsafe environment their own DMQ group numbers.
    
    2. Have a common bus.init and group.init which lists both machines with
    the Initiate flag as "N" in the %XGROUP section.
    
    3. In the group.init add any XGROUP links and specify the Initiate flag
    as "Y".
    
    4. Put the MRS/PCJ/DLJ on one of the disks managed by DECsafe (only one
    of the machines will own the shared disks at any one time).
    
    5. Modify the ASE start script so that it starts the DMQ group 
    
    6. Modify the ASE stop script so that the DMQ group is shutdown when
    the service is moved.
    
    7. On the remote groups (NT, UNIX, VMS, etc.) add 2 entries in the
    %XGROUP section for the cluster and set the Initiate/GenCnt flag to "N"
    
    8. If you use the Windows Client Library then put the IP alias address
    in the PC's DMQ.INI - the dmqcls happily accepts connections on the
    machine or alias addresses.
    
    9. Finally, if the DECsafe machines act as a "server" for remote groups
    you will need to employ a hot failover strategy (using the avail
    services, application level ping, etc.)
    
    Regards,
    Alan.

    The way we set up DmQ v3.2A on HP-UX with ServiceGuard (similar to ASE)
    is to use the hostname that resolves to the "floating" IP address that
    moves with the application (what you are calling the alias address?) in
    the cross-group tables.  This requires only a single xgroup entry both
    locally for the server group itself, and in the remote client xgroup
    tables.
    
    V3.2A is able to determine if the address the hostname in the group's
    own entry maps to an address stacked on any of the machine's
    interfaces, and then can act using that address and hostname (see the
    v3.2A release notes for more details, and the ability to use multiple
    addresses for the same group).
    
    Will this same scheme work for Digital Unix?
    
    Example:
    
    we have a cluster of two HP-UX servers forming a MQS-to-DmQ bridge,
    qmb1 and qmb2.  The bridge "package" has a floating IP address with the
    DNS name qmbpkg2.  The bridge group is 1408, hence the entry in the
    group.init file for group 1408 is:
    
    QMB1408 1408 qmbpkg2 N 5000000 60 30 35000 TCPIP 18108  
    
    which works on either node in the cluster, as long as the package is
    switched to that node.  At the remote end, xgroup connections actually
    appear to be coming from qmbpkg2.
    
    (MQSeries has no IP-hostname/address-based security checks, so floating
    IPs has never been a problem - only security is a problem!)

    
    I have not tried V3.2A in an ASE environment so I haven't used the
    alias addressing capability.
    
    If the "cluster" has a XGROUP connection to a OpenVMS server how do you
    configure the XGROUP table on the OpenVMS server - do you put two
    entries for the UNIX group or 1 entry for the alias/floating hostname?
    
    Alan.

    I haven't done this on a remote VMS system, only remote Unix systems
    (HP, Sun), but yes, only one entry for the alias/floating host name.
    It works quite well.

Hi 

thanks a lot for the great input. 


Cheers

Marco