Conference orarep::nomahs::dbms

2636.0. "VAX 7000 Applications to AS8400 remote?" by ORAREP::SLOVAX::NEWMAN () Tue May 27 1997 15:03

    I have a customer who would like to move to Alpha by setting up remote
    access from his VAX 7000s to an AS8400 or AS4100.  This would be done
    by changing the logical which points to the files to include the node
    where the files really are located (on the alpha).
    
    He has the following concerns that I hope someone can answer:
    
    1. Population of 700 users and 200 simultaneous connect limit for
    DECnet to DBM$OBJECT
    
    If each user opens a decnet session when they bind to the database and
    we need to support 700 simultaneous binds, then I think we have a
    DECnet problem.
    
    If each user opens a decnet session when they execute a transaction,
    then 200 of the 700 could be active at one time.
    
    Which is the way it really works?
    
    1a. Can this be done with tcp/ip to get around the 200 connect limit?
    
    2. If the remote node is a cluster of AS4100s, then how does DECnet
    select which node of the cluster to use?
    
    3. Customer asked about the difference between AS4100 and AS8400 for
    remote DBMS support.
    
    I said it was much more dependant on the database, database caching,
    i/o hardware, number of CPUs, amount of available memory, etc rather
    than the size of the box.  
    
    Of course, the AS8400 could have more CPUs and more memory but at 4
    CPUs and 4Gb of memory, same number of KZPSAs, disks etc., I thought
    the AS8400 would be faster than an AS4100.
    
    Does anyone have any real experience here?
    
    4. In configuring this solution, I selected the following priority
    order of hardware to be considered:
    
    1. Memory
    2. PCI / I/O bandwidth and response times
    3. CPU Speed
    4. Number of SMP CPUs
    
    5.  They are limited to OVMS 6.2-1h3 and cannot go to OVMS 7.1
    immediately.
    
    What, if any, are the restrictions when running 6.2-1h3?
    
    Thanks for you advice.
    
    Cheers,
    
    Sandy
    
                                              

Sandy,

I can answer a couple of these...

>    If each user opens a decnet session when they bind to the database and
>    we need to support 700 simultaneous binds, then I think we have a
>    DECnet problem.
    
>    If each user opens a decnet session when they execute a transaction,
>    then 200 of the 700 could be active at one time.
    
>    Which is the way it really works?
    

We would assign the channel as part of our bind sequence, which would happen
during the first READY. We would disconnect at explicit UNBIND or at image
termination.  

>    1a. Can this be done with tcp/ip to get around the 200 connect limit?
    
Remote DBMS applications don't support TCP/IP.

paul