Re: Hot Standby (or Failover) support.

In article <89E152B.0389001DA2.uuout_at_compudata.com>, BARRY ROOMBERG <barry.roomberg_at_compudata.com> wrote:
>-> Can anyone tell me what Oracle offers for "Hot Standby" (normally
>-> automatic) or "Failover" (normally manual) support? I'm particularly
>-> interested in Sun, HP, DEC(Alpha), IBM RS/6000 and NT machines.
>
>I don't know what they "OFFER" for this, but I've created it
>by putting a backup machine in recovery mode and applying
>the archived logs as they show up. I did it under SCO Unix,
>but it should be easy in networked environment.

HACMP/6000 is an IBM LPP for the RS/6000 that enables a cluster (2-4 RS/6000s) to provide highly available services to clients, with minimal interruption in the event of system or component failure.

You can configure an HACMP cluster and ORACLE in one of two ways: concurrent (Oracle Parallel Server) or non-concurrent.

In concurrent mode, an instance of ORACLE runs on all cluster nodes. Each node has access to the raw logical volumes. An HACMP daemon (cllockd) provides locking services to the ORACLE server, to arbitrate requests for the shared, concurrent volume. (File systems can not be used in concurrent mode.) If a node fails, client requests are directed to the surviving node.

In non-concurrent mode, one node is active and one is a standby. When the active node fails, it's applications, disk resources, and IP Address can be automatically taken over by a "standby" node. Clients experience a brief interruption in service, and then can continue processing. If a component (physical volume, communication adapter) fails, mirror or standby components step in for the failed original.

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