Oracle 9i on OpenVMS Clusters

[Douglas Buxton]

I'm looking for any information on running Oracle 9i (or 10g) on OpenVMS clusters. The Oracle people we have say that you can't run instances of oracle on multiple nodes in a cluster (withoug RAC) because the db properties are relegated to a node. Anyone doing it or done it before.

[Hein van den Heuvel · Accepted solution]

They are right. You can not run the same instance on multiple nodes without RAC (or OPS in 8i).
There has to be synchronization between the access which RAC will manage with its lock manager.
Beside synchronization RAC will also offer 'cache fusion', moving blocks from cache to cache directly without needed to bounce of the disk (as they did in OPS)

You can run other instances on other nodes.
So if in your cluster you have node X and Y
and oracle instance DEV, TST and PRD.
You can run
- all on X,
- all on Y,
- DEV on X, TST + PRD on Y
- TST on X, DEV + PRD on Y
- the other 4 combo's
You can NOT run
- PRD on X and Y
- the other 2 double's

hth,
Hein.

[Douglas Buxton]

That being the case, then the use of VMS clusters with Oracle is limited if you have a small number of instances (large DB's, but only 3 or 3) and don't want to pay $400 per user for RAC. Is that about the size of it?

[Martin P.J. Zinser]

Hello Douglas,

well if you do want to take care of performance features like Row cache the situation is not that much different even on Oracle Rdb (as opposed to Oracle 8/9/10), although with JCCs LogMiner Loader (www.jcc.com) one can try to work around this a bit.

Greetings, Martin

[Douglas Buxton]

Our issue isn't performance (although I've never seen a better performance product that VMS clustering), it is more an issue of cost. $400 per user for RAC, a new cluster product to share data, network only cluster interconnection media, etc. etc. etc. Just in the cost area, $80,000 for 200 user licenses will by approx. 11 ES45 cluster licenses. And we have to use a product that, from all I can tell, is not all that stable yet. So we have to use VMS clustering for stability AND incurr the cost of RAC as well. Not a good scenario from our standpoint.

[Jeff Wolfe_1]

Assuming your issue is about fault tolerance then RAC is the only seemless solution. If access is the issue, any node can in the cluster can assess the database as long as the TNSNAMES.ORA file is set up properly. So, one node will be the DB server and the other nodes become clients. We also went throught the trouble of creating init files for the DB on the other nodes, so that in the event of a node failure, we could bring up the DB on another other node. Not as nice as how Rdb works, but it is a workable solution.

[Douglas Buxton]

Did you create a separate ora_root:[dbs]sid_.properties for all other nodes in the cluster changing the node association
to prevent oracle from saying you can't start it up?
ORA_DB_LOGICALS.COM - ERROR:
Attempting to setup environment for instance DEVDB on the wrong node.
You are on node "GRAKLE", but the ora_root:[dbs]sid_DEVDB.properties
file indicates this instance is associated with node "OSPREY"."

[Jeff Wolfe_1]

First let me say that we are still using 8i. We did create a set of sid.ORA files for each node in the cluster. These files were in the same cluster common "admin" directory. I took us a few test tries before we found everything that needed to be changed. But we eventually got the database to start.

[Hein van den Heuvel]

Yes well, I am fortunate(?) to be able to be able to ignore licensing costs in my day-to-day work. I put a questionmark there because it detaches me from 'the real worlds' where obviously everthing counts towards an ultimate 'TCO'.

I don't suppose the the license cost is negotiable as a combination of CPU's and RAC such that 2 nodes with 2 cpus would price more similar to 1 node with 4 (assuming you can restrict oracle to 2 out of 4 cpus in a box).

Anyway... a VMS cluster remains (IMHO) very valuable. For starters there is ofcourse the near-transparant failover for the instances.
- the ability to pick and choose node where to run an application (oracle instance)
- the ability to do generic maintenance (backups) from any node
- the 'one system image' managemetn
- on and on...

Thanks for your real life feedback!

Hein.

[Martin P.J. Zinser]

Hello,

if you are able to make a tradeoff between performance and cost, Oracle Rdb actually might be an alternative. As far as I know the costs for the database server are the same as for Oracle Classic and support for VMS clusters is build-in (as long as you do not use row caches).

Greetings, Martin