Failover using TNSNAMES.ora on a HA Cluster

From: Alan Patil <Alan_Patil_at_msn.com>
Date: Tue, 10 Nov 1998 11:42:15 -0000
Message-ID: <e#RZp7JD#GA.184@upnetnews05>

Does anyone out there use a HA parallel server cluster (two nodes with one acting as a backup). I need to setup failover from one node to the other when the primary goes down and the Oracle documentation alludes to the fact that TNSNAMES.ora can be setup on the client to failover to the other node.

Unfortunately the example they give using the backup option in tnsnames suggests the client can go to either node initially ( I only want it to go the primary initially, and switch over to the secondary when the primary fails and then switch back when the primary is OK). Am I correct in this assumption or do I have to use a shell script to manually do failover.

Oracle example from the parallel server docs:-

group g1=(i11)
group g2=(i12)
group gc=(i11,i12)

In the TNSNAMES.ORA file you would enter:

i11 = (DESCRIPTION=

(ADDRESS=(PROTOCOL=TCP)(HOST=host1)(PORT=1521))
(CONNECT_DATA=(SID=i11)(SERVER=DEDICATED)

           (FAILOVER_MODE=(TYPE=select)(METHOD=preconnect)
               (BACKUP=i12))
        )
      )
i12 = (DESCRIPTION=


        (ADDRESS=(PROTOCOL=TCP)(HOST=host2)(PORT=1521))


        (CONNECT_DATA=(SID=i12)(SERVER=DEDICATED)


             (FAILOVER_MODE=(TYPE=select)(METHOD=preconnect)
               (BACKUP=i11))
        )
      )
______________________________________________________________

Al Received on Tue Nov 10 1998 - 05:42:15 CST