Re: Is OpenVMS certified yet for 64-way Hard partitions (GS1280 M64).

JF Mezei wrote:
Doug Phillips wrote:
I understand the all-the-eggs-in-one-basket thing, but at what level
does the application need to be "cluster aware"?

In its design. Consider a "server" process that receives requests and
queues them for processing by itself and assumed that it is the only
process accessing the database/files because all requests are funnelled
through it.


Right. Sorry you clipped the next part of my post. Say a program reads
something from someplace (screen, keyboard, machine,...), builds a
data-record key and requests a data-record read or write. It then gets
an indication of success or failure.

Where the record came from, or what sent the error status isn't a
matter of concern at that level. Process the record or handle the
error. And, at that level is the majority of the code base and the
substance of the application.

Making this work in a cluster requires substantial changes because you
would now have 2 or more processes accessing the same database.


But, that's what database servers do.


VMS clustering was "transparent" in the days of interactive sessions
with users at the $ sign all day and running TPU/Compilers. But when you
get into server type applications, the plot thickens. distributing
transactions to spread the load amongst the available nodes is not
trivial unless you can be sure that no client casches IPs adresses and
continuously do DNS requests to make use of DNS load balancing for instance.


And that's all too deep for the API to even care about. VMS clusters
would need different RTL's & such than Veritas or whatever, but the API
should be the same.


It is definitely doable. But it isn't "out of the box" that way for
every type of application.

You're right.

.

Relevant Pages

  • Re: Active/Active configuration
    ... Almost everything out there is onActive/Passive.Setting up another instance in a cluster is no different than setting up the ... how does sql server knows which instance an application/user is refering to?You need a separate IP addresse for each clustered instance. ... you really shouldn't share a single network. ... Is this a valid assumption?You may get better performance by virute of running each database on its own ...
    (microsoft.public.sqlserver.clustering)
  • Re: What is the best backup solution for failover cluster SQL Server
    ... Backing up your SQL database in a clustered environment is not different from a normal server. ... Create a cluster disk share so in the event of a fail over, all nodes will have access to the backup share. ...
    (microsoft.public.sqlserver.clustering)
  • Re: SQL Server Architecture
    ... Mirror WRITE database fails back to primary WRITE database (which is ... now running on the secondary in the cluster). ... the primary server before Windows Clustering does. ... in addition to the database mirroring setup you described. ...
    (microsoft.public.sqlserver.clustering)
  • LSASS.exe slowly increasing in memory and VM usage
    ... I currently have a 2 node cluster with Windows 2000 Advance Server ... Description: 18264: Database backed up: Database: BEDB, ...
    (microsoft.public.win2000.advanced_server)
  • Re: Is it true that All communication between front-end and back-end servers goes through TCP port
    ... Mail server administrator, MCSA/MCSE ... > port to cluster and that MS would be using XML as the format over port 80 ... >> from any front-end server in your organization. ... Proxy requests are ...
    (microsoft.public.exchange2000.general)